This patch adds support in the MC layer for parsing and assembling the
4-operand add instruction needed for TLS addressing. This also involves
parsing the %tprel_hi, %tprel_lo and %tprel_add operand modifiers.
Differential Revision: https://reviews.llvm.org/D55341
llvm-svn: 357698
This patch allows symbols appended with @plt to parse and assemble with the
R_RISCV_CALL_PLT relocation.
Differential Revision: https://reviews.llvm.org/D55335
Patch by Lewis Revill.
llvm-svn: 357470
This patch replaces the addition of VK_RISCV_CALL in RISCVMCCodeEmitter by
creating the RISCVMCExpr when tail/call are parsed, or in the codegen case
when the callee symbols are created.
This required adding a new CallSymbol operand to allow only adding
VK_RISCV_CALL to tail/call instructions.
This patch will allow further expansion of parsing and codegen to easily
include PLT symbols which must generate the R_RISCV_CALL_PLT relocation.
Differential Revision: https://reviews.llvm.org/D55560
Patch by Lewis Revill.
llvm-svn: 357396
This patch adds an implementation of a PC-relative addressing sequence to be
used when -mcmodel=medium is specified. With absolute addressing, a 'medium'
codemodel may cause addresses to be out of range. This is because while
'medium' implies a 2 GiB addressing range, this 2 GiB can be at any offset as
opposed to 'small', which implies the first 2 GiB only.
Note that LLVM/Clang currently specifies code models differently to GCC, where
small and medium imply the same functionality as GCC's medlow and medany
respectively.
Differential Revision: https://reviews.llvm.org/D54143
Patch by Lewis Revill.
llvm-svn: 357393
Adds a `seto` pattern expansion. Without it the lowerings of `fcmp one` and
`fcmp ord` would be inefficient due to an unoptimized double negation.
Differential Revision: https://reviews.llvm.org/D59699
llvm-svn: 357378
A pcrel_lo will point to the associated pcrel_hi fixup which in turn points to
the real target. RISCVMCExpr::evaluatePCRelLo will work around this
indirection in order to allow the fixup to be evaluate properly. However, if
relocations are forced (e.g. due to linker relaxation is enabled) then its
evaluation is undesired and will result in a relocation with the wrong target.
This patch modifies evaluatePCRelLo so it will not try to evaluate if the
fixup will be forced as a relocation. A new helper method is added to
RISCVAsmBackend to query this.
Differential Revision: https://reviews.llvm.org/D59686
llvm-svn: 357374
This patch adds support for the RISC-V hard float ABIs, building on top of
rL355771, which added basic target-abi parsing and MC layer support. It also
builds on some re-organisations and expansion of the upstream ABI and calling
convention tests which were recently committed directly upstream.
A number of aspects of the RISC-V float hard float ABIs require frontend
support (e.g. flattening of structs and passing int+fp for fp+fp structs in a
pair of registers), and will be addressed in a Clang patch.
As can be seen from the tests, it would be worthwhile extending
RISCVMergeBaseOffsets to handle constant pool as well as global accesses.
Differential Revision: https://reviews.llvm.org/D59357
llvm-svn: 357352
The SplitF64 node is used on RV32D to convert an f64 directly to a pair of i32
(necessary as bitcasting to i64 isn't legal). When performed on a ConstantFP,
this will result in a FP load from the constant pool followed by a store to
the stack and two integer loads from the stack (necessary as there is no way
to directly move between f64 FPRs and i32 GPRs on RV32D). It's always cheaper
to just materialise integers for the lo and hi parts of the FP constant, so do
that instead.
llvm-svn: 357341
Adds two patterns to improve the codegen of GPR value comparisons with small
constants. Instead of first loading the constant into another register and then
doing an XOR of those registers, these patterns directly use the constant as an
XORI immediate.
llvm-svn: 356990
The RISC-V ISA defines RV32E as an alternative "base" instruction set
encoding, that differs from RV32I by having only 16 rather than 32 registers.
This patch adds basic definitions for RV32E as well as MC layer support
(assembling, disassembling) and tests. The only supported ABI on RV32E is
ILP32E.
Add a new RISCVFeatures::validate() helper to RISCVUtils which can be called
from codegen or MC layer libraries to validate the combination of TargetTriple
and FeatureBitSet. Other targets have similar checks (e.g. erroring if SPE is
enabled on PPC64 or oddspreg + o32 ABI on Mips), but they either duplicate the
checks (Mips), or fail to check for both codegen and MC codepaths (PPC).
Codegen for the ILP32E ABI support and RV32E codegen are left for a future
patch/patches.
Differential Revision: https://reviews.llvm.org/D59470
llvm-svn: 356744
This patch optimizes the emission of a sequence of SELECTs with the same
condition, avoiding the insertion of unnecessary control flow. Such a sequence
often occurs when a SELECT of values wider than XLEN is legalized into two
SELECTs with legal types. We have identified several use cases where the
SELECTs could be interleaved with other instructions. Therefore, we extend the
sequence to include non-SELECT instructions if we are able to detect that the
non-SELECT instructions do not impact the optimization.
This patch supersedes https://reviews.llvm.org/D59096, which attempted to
address this issue by introducing a new SelectionDAG node. Hat tip to Eli
Friedman for his feedback on how to best handle this issue.
Differential Revision: https://reviews.llvm.org/D59355
Patch by Luís Marques.
llvm-svn: 356741
Indicates in the TargetLowering interface that conversions from CC logic to
bitwise logic are allowed. Adds tests that show the benefit when optimization
opportunities are detected. Also adds tests that show that when the optimization
is not applied correct code is generated (but opportunities for other
optimizations remain).
Differential Revision: https://reviews.llvm.org/D59596
Patch by Luís Marques.
llvm-svn: 356740
RISCVAsmParser::ParseRegister is called from AsmParser::parseRegisterOrNumber,
which in turn is called when processing CFI directives. The RISC-V
implementation wasn't setting RegNo, and so was incorrect. This patch address
that and adds cfi directive tests that demonstrate the fix. A follow-up patch
will factor out the register parsing logic shared between ParseRegister and
parseRegister.
llvm-svn: 356329
The CSR renaming further prepares the way for an upcoming patch adding support for more
RISC-V ABIs.
Modify RISCVRegisterInfo::getCalleeSavedRegs and
RISCVRegisterInfo::getReservedRegs to do MF->getSubtarget<RISCVSubtarget>()
once rather than multiple times.
llvm-svn: 356123
This follows similar logic in the ARM and Mips backends, and allows the free
use of s0 in functions without a dedicated frame pointer. The changes in
callee-saved-gprs.ll most clearly show the effect of this patch.
llvm-svn: 356063
RISCVDisassembler was incorrectly using sizeof(Arr) when it should have used
sizeof(Arr)/sizeof(Arr[0]). Update to use array_lengthof instead.
llvm-svn: 356035
If a symbol points to the end of a fragment, instead of searching for
fixups in that fragment, search in the next fragment.
Fixes spurious assembler error with subtarget change next to "la"
pseudo-instruction, or expanded equivalent.
Alternate proposal to fix the problem discussed in
https://reviews.llvm.org/D58759.
Testcase by Ana Pazos.
Differential Revision: https://reviews.llvm.org/D58943
llvm-svn: 355946
AtomicCmpSwapWithSuccess is legalised into an AtomicCmpSwap plus a comparison.
This requires an extension of the value which, by default, is a
zero-extension. When we later lower AtomicCmpSwap into a PseudoCmpXchg32 and then expanded in
RISCVExpandPseudoInsts.cpp, the lr.w instruction does a sign-extension.
This mismatch of extensions causes the comparison to fail when the compared
value is negative. This change overrides TargetLowering::getExtendForAtomicOps
for RISC-V so it does a sign-extension instead.
Differential Revision: https://reviews.llvm.org/D58829
Patch by Ferran Pallarès Roca.
llvm-svn: 355869
The RISC-V Assembly Programmer's Manual defines fp as another alias of x8.
However, our tablegen rules only recognise s0. This patch adds fp as another
alias of x8. GCC also accepts fp.
Differential Revision: https://reviews.llvm.org/D59209
Patch by Ferran Pallarès Roca.
llvm-svn: 355867
This patch adds proper handling of -target-abi, as accepted by llvm-mc and
llc. Lowering (codegen) for the hard-float ABIs will follow in a subsequent
patch. However, this patch does add MC layer support for the hard float and
RVE ABIs (emission of the appropriate ELF flags
https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md#-file-header).
ABI parsing must be shared between codegen and the MC layer, so we add
computeTargetABI to RISCVUtils. A warning will be printed if an invalid or
unrecognized ABI is given.
Differential Revision: https://reviews.llvm.org/D59023
llvm-svn: 355771
Summary:
Floating-point CSRs should be accessible even when F extension is not enabled.
But pseudo instructions that access floating point CSRs still require the F extension.
GNU tools already implement this behavior. RISC-V spec is pending update to reflect
this behavior and to extend it to pseudo instructions that access floating point CSRs.
Reviewers: asb
Reviewed By: asb
Subscribers: asb, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, llvm-commits
Differential Revision: https://reviews.llvm.org/D58932
llvm-svn: 355753
Allow load/store instructions with implied zero offset for compatibility with
GNU assembler.
Differential Revision: https://reviews.llvm.org/D57141
Patch by James Clarke.
llvm-svn: 354581
Summary:
Those pseudo-instructions are making load/store instructions able to
load/store from/to a symbol, and its always using PC-relative addressing
to generating a symbol address.
Reviewers: asb, apazos, rogfer01, jrtc27
Differential Revision: https://reviews.llvm.org/D50496
llvm-svn: 354430
This patch also introduces the emitAuipcInstPair helper, which is then used
for both emitLoadAddress and emitLoadLocalAddress.
Differential Revision: https://reviews.llvm.org/D55325
Patch by James Clarke.
llvm-svn: 354111
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html
This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.
This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.
There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.
Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii
Differential Revision: https://reviews.llvm.org/D53765
llvm-svn: 353563
This patch:
* Adds necessary RV64D codegen patterns
* Modifies CC_RISCV so it will properly handle f64 types (with soft float ABI)
Note that in general there is no reason to try to select fcvt.w[u].d rather than fcvt.l[u].d for i32 conversions because fptosi/fptoui produce poison if the input won't fit into the target type.
Differential Revision: https://reviews.llvm.org/D53237
llvm-svn: 352833
This requires a little extra work due tothe fact i32 is not a legal type. When
call lowering happens post-legalisation (e.g. when an intrinsic was inserted
during legalisation). A bitcast from f32 to i32 can't be introduced. This is
similar to the challenges with RV32D. To handle this, we introduce
target-specific DAG nodes that perform bitcast+anyext for f32->i64 and
trunc+bitcast for i64->f32.
Differential Revision: https://reviews.llvm.org/D53235
llvm-svn: 352807
Linker relaxation may change code size. We need to fix up the alignment
of alignment directive in text section by inserting Nops and R_RISCV_ALIGN
relocation type. So then linker could satisfy the alignment by removing Nops.
To do this:
1. Add shouldInsertExtraNopBytesForCodeAlign target hook to calculate
the Nops we need to insert.
2. Add shouldInsertFixupForCodeAlign target hook to insert
R_RISCV_ALIGN fixup type.
Differential Revision: https://reviews.llvm.org/D47755
llvm-svn: 352616
DAGCombiner::visitBITCAST will perform:
fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
As shown in double-bitmanip-dagcombines.ll, this can be advantageous. But
RV32FD doesn't use bitcast directly (as i64 isn't a legal type), and instead
uses RISCVISD::SplitF64. This patch adds an equivalent DAG combine for
SplitF64.
llvm-svn: 352247
Follow the same custom legalisation strategy as used in D57085 for
variable-length shifts (see that patch summary for more discussion). Although
we may lose out on some late-stage DAG combines, I think this custom
legalisation strategy is ultimately easier to reason about.
There are some codegen changes in rv64m-exhaustive-w-insts.ll but they are all
neutral in terms of the number of instructions.
Differential Revision: https://reviews.llvm.org/D57096
llvm-svn: 352171
The previous DAG combiner-based approach had an issue with infinite loops
between the target-dependent and target-independent combiner logic (see
PR40333). Although this was worked around in rL351806, the combiner-based
approach is still potentially brittle and can fail to select the 32-bit shift
variant when profitable to do so, as demonstrated in the pr40333.ll test case.
This patch instead introduces target-specific SelectionDAG nodes for
SHLW/SRLW/SRAW and custom-lowers variable i32 shifts to them. pr40333.ll is a
good example of how this approach can improve codegen.
This adds DAG combine that does SimplifyDemandedBits on the operands (only
lower 32-bits of first operand and lower 5 bits of second operand are read).
This seems better than implementing SimplifyDemandedBitsForTargetNode as there
is no guarantee that would be called (and it's not for e.g. the anyext return
test cases). Also implements ComputeNumSignBitsForTargetNode.
There are codegen changes in atomic-rmw.ll and atomic-cmpxchg.ll but the new
instruction sequences are semantically equivalent.
Differential Revision: https://reviews.llvm.org/D57085
llvm-svn: 352169
Previously we had names like 'Call' or 'Tail'. This potentially clashes with
the naming scheme used elsewhere in RISCVInstrInfo.td. Many other backends
would use names like AArch64call or PPCtail. I prefer the SystemZ approach,
which uses prefixed all-lowercase names. This matches the naming scheme used
for target-independent SelectionDAG nodes.
llvm-svn: 351823
Avoid the infinite loop caused by the target DAG combine converting ANYEXT to
SIGNEXT and the target-independent DAG combine logic converting back to
ANYEXT. Do this by not adding the new node to the worklist.
Committing directly as this definitely doesn't make the problem any worse, and
I intend to follow-up with a patch that avoids this custom combiner logic
altogether and just lowers the i32 operations to a target-specific
SelectionDAG node. This should be easier to reason about and improve codegen
quality in some cases (though may miss out on some later DAG combines).
llvm-svn: 351806
This broke the RISCV build, and even with that fixed, one of the RISCV
tests behaves surprisingly differently with asserts than without,
leaving there no clear test pattern to use. Generally it seems bad for
hte IR to differ substantially due to asserts (as in, an alloca is used
with asserts that isn't needed without!) and nothing I did simply would
fix it so I'm reverting back to green.
This also required reverting the RISCV build fix in r351782.
llvm-svn: 351796
The break isn't strictly needed yet as there is no subsequent entry in the
case. But adding to prevent mistakes further down the road.
llvm-svn: 351785
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
In order to support codegen RV64A, this patch:
* Introduces masked atomics intrinsics for atomicrmw operations and cmpxchg
that use the i64 type. These are ultimately lowered to masked operations
using lr.w/sc.w, but we need to use these alternate intrinsics for RV64
because i32 is not legal
* Modifies RISCVExpandPseudoInsts.cpp to handle PseudoAtomicLoadNand64 and
PseudoCmpXchg64
* Modifies the AtomicExpandPass hooks in RISCVTargetLowering to sext/trunc as
needed for RV64 and to select the i64 intrinsic IDs when necessary
* Adds appropriate patterns to RISCVInstrInfoA.td
* Updates test/CodeGen/RISCV/atomic-*.ll to show RV64A support
This ends up being a fairly mechanical change, as the logic for RV32A is
effectively reused.
Differential Revision: https://reviews.llvm.org/D53233
llvm-svn: 351422
As discussed on llvm-dev
<http://lists.llvm.org/pipermail/llvm-dev/2018-December/128497.html>, we have
to be careful when trying to select the *w RV64M instructions. i32 is not a
legal type for RV64 in the RISC-V backend, so operations have been promoted by
the time they reach instruction selection. Information about whether the
operation was originally a 32-bit operations has been lost, and it's easy to
write incorrect patterns.
Similarly to the variable 32-bit shifts, a DAG combine on ANY_EXTEND will
produce a SIGN_EXTEND if this is likely to result in sdiv/udiv/urem being
selected (and so save instructions to sext/zext the input operands).
Differential Revision: https://reviews.llvm.org/D53230
llvm-svn: 350993
This restores support for selecting the SLLW/SRLW/SRAW instructions, which was
removed in rL348067 as the previous patterns made some unsafe assumptions.
Also see the related llvm-dev discussion
<http://lists.llvm.org/pipermail/llvm-dev/2018-December/128497.html>
Ultimately I didn't introduce a custom SelectionDAG node, but instead added a
DAG combine that inserts an AssertZext i5 on the shift amount for an i32
variable-length shift and also added an ANY_EXTEND DAG-combine which will
instead produce a SIGN_EXTEND for an i32 variable-length shift, increasing the
opportunity to safely select SLLW/SRLW/SRAW.
There are obviously different ways of addressing this (a number discussed in
the llvm-dev thread), so I'd welcome further feedback and comments.
Note that there are now some cases in
test/CodeGen/RISCV/rv64i-exhaustive-w-insts.ll where sraw/srlw/sllw is
selected even though sra/srl/sll could be used without any extra instructions.
Given both are semantically equivalent, there doesn't seem a good reason to
prefer one vs the other. Given that would require more logic to still select
sra/srl/sll in those cases, I've left it preferring the *w variants.
Differential Revision: https://reviews.llvm.org/D56264
llvm-svn: 350992
This further improves compatibility with GNU as, allowing input such as the
following to be assembled:
.equ CONST, 0x123456
li a0, CONST
addi a0, a0, %lo(CONST)
.equ CONST, 1
slli a0, a0, CONST
Note that we don't have perfect compatibility with gas, as it will avoid
emitting a relocation in this case:
addi a0, a0, %lo(CONST2)
.equ CONST2, 0x123456
Thanks to Shiva Chen for suggesting a better way to approach this during review.
Differential Revision: https://reviews.llvm.org/D52298
llvm-svn: 350831
This is a update to D43157 to correctly handle fixup_riscv_pcrel_lo12.
Notable changes:
Rebased onto trunk
Handle and test S-type
Test case pcrel-hilo.s is merged into relocations.s
D43157 description:
VK_RISCV_PCREL_LO has to be handled specially. The MCExpr inside is
actually the location of an auipc instruction with a VK_RISCV_PCREL_HI fixup
pointing to the real target.
Differential Revision: https://reviews.llvm.org/D54029
Patch by Chih-Mao Chen and Michael Spencer.
llvm-svn: 349764
Adds support for the various RISC-V FMA instructions (fmadd, fmsub, fnmsub, fnmadd).
The criteria for choosing whether a fused add or subtract is used, as well as
whether the product is negated or not, is whether some of the arguments to the
llvm.fma.* intrinsic are negated or not. In the tests, extraneous fadd
instructions were added to avoid the negation being performed using a xor
trick, which prevented the proper FMA forms from being selected and thus
tested.
The FMA instruction patterns might seem incorrect (e.g., fnmadd: -rs1 * rs2 -
rs3), but they should be correct. The misleading names were inherited from
MIPS, where the negation happens after computing the sum.
The llvm.fmuladd.* intrinsics still do not generate RISC-V FMA instructions,
as that depends on TargetLowering::isFMAFasterthanFMulAndFAdd.
Some comments in the test files about what type of instructions are there
tested were updated, to better reflect the current content of those test
files.
Differential Revision: https://reviews.llvm.org/D54205
Patch by Luís Marques.
llvm-svn: 349023
Adds fatal errors for any target that does not support the Tiny or Kernel
codemodels by rejigging the getEffectiveCodeModel calls.
Differential Revision: https://reviews.llvm.org/D50141
llvm-svn: 348585
As noted by Eli Friedman <https://reviews.llvm.org/D52977?id=168629#1315291>,
the RV64I shift patterns for SLLW/SRLW/SRAW make some incorrect assumptions.
SRAW assumed that (sext_inreg foo, i32) could only be produced when
sign-extended an i32. However, it can be produced by input such as:
define i64 @tricky_ashr(i64 %a, i64 %b) {
%1 = shl i64 %a, 32
%2 = ashr i64 %1, 32
%3 = ashr i64 %2, %b
ret i64 %3
}
It's important not to select sraw in the above case, because sraw only uses
bits lower 5 bits from the shift, while a shift of 32-63 would be valid.
Similarly, the patterns for srlw assumed (and foo, 0xffffffff) would only be
produced when zero-extending a value that was originally i32 in LLVM IR. This
is obviously incorrect.
This patch removes the SLLW/SRLW/SRAW shift patterns for the time being and
adds test cases that would demonstrate a miscompile if the incorrect patterns
were re-added.
llvm-svn: 348067
This patch adds CSR instructions aliases for the cases where the instruction
takes an immediate operand but the alias doesn't have the i suffix. This is
necessary for gas/gcc compatibility.
gas doesn't do a similar conversion for fsflags or fsrm, so this should be
complete.
Differential Revision: https://reviews.llvm.org/D55008
Patch by Luís Marques.
llvm-svn: 347991
This patch adds support for UNIMP in both 32- and 16-bit forms. The 32-bit
form can be seen as a variant of the ECALL/EBREAK/etc. family of instructions.
The 16-bit form is just all zeroes, which isn't a valid RISC-V instruction,
but still follows the 16-bit instruction form (i.e. bits 0-1 != 11).
Until recently unimp was undocumented and supported just by binutils, which
printed unimp for either the 16 or 32-bit form. Both forms are now documented
<https://github.com/riscv/riscv-asm-manual/pull/20> and binutils now supports
c.unimp <https://sourceware.org/ml/binutils-cvs/2018-11/msg00179.html>.
Differential Revision: https://reviews.llvm.org/D54316
Patch by Luís Marques.
llvm-svn: 347988
DAGTypeLegalizer::PromoteSetCCOperands currently prefers to zero-extend
operands when it is able to do so. For some targets this is more expensive
than a sign-extension, which is also a valid choice. Introduce the
isSExtCheaperThanZExt hook and use it in the new SExtOrZExtPromotedInteger
helper. On RISC-V, we prefer sign-extension for FromTy == MVT::i32 and ToTy ==
MVT::i64, as it can be performed using a single instruction.
Differential Revision: https://reviews.llvm.org/D52978
llvm-svn: 347977
As discussed in the RFC
<http://lists.llvm.org/pipermail/llvm-dev/2018-October/126690.html>, 64-bit
RISC-V has i64 as the only legal integer type. This patch introduces patterns
to support codegen of the new instructions
introduced in RV64I: addiw, addiw, subw, sllw, slliw, srlw, srliw, sraw,
sraiw, ld, sd.
Custom selection code is needed for srliw as SimplifyDemandedBits will remove
lower bits from the mask, meaning the obvious pattern won't work:
def : Pat<(sext_inreg (srl (and GPR:$rs1, 0xffffffff), uimm5:$shamt), i32),
(SRLIW GPR:$rs1, uimm5:$shamt)>;
This is sufficient to compile and execute all of the GCC torture suite for
RV64I other than those files using frameaddr or returnaddr intrinsics
(LegalizeDAG doesn't know how to promote the operands - a future patch
addresses this).
When promoting i32 sltu/sltiu operands, it would be more efficient to use
sign-extension rather than zero-extension for RV64. A future patch adds a hook
to allow this.
Differential Revision: https://reviews.llvm.org/D52977
llvm-svn: 347973
Utilise a similar ('late') lowering strategy to D47882. The changes to
AtomicExpandPass allow this strategy to be utilised by other targets which
implement shouldExpandAtomicCmpXchgInIR.
All cmpxchg are lowered as 'strong' currently and failure ordering is ignored.
This is conservative but correct.
Differential Revision: https://reviews.llvm.org/D48131
llvm-svn: 347914
This adds support in the RISCVAsmParser the storing of Subtarget feature bits to a stack so that they can be pushed/popped to enable/disable multiple features at once.
Differential Revision: https://reviews.llvm.org/D46424
Patch by Lewis Revill.
llvm-svn: 347774
The RISC-V ISA manual was updated on 2018-11-07 (commit 00557c3) to define a
new compressed instruction format, RVC format CA (no actual instruction
encodings were changed). This patch updates the RISC-V backend to define the
new format, and to use it in the relevant instructions.
Differential Revision: https://reviews.llvm.org/D54302
Patch by Luís Marques.
llvm-svn: 347043
This commit introduces support for materialising 64-bit constants for RV64I,
making use of the RISCVMatInt::generateInstSeq helper in order to share logic
for immediate materialisation with the MC layer (where it's used for the li
pseudoinstruction).
test/CodeGen/RISCV/imm.ll is updated to test RV64, and gains new 64-bit
constant tests. It would be preferable if anyext constant returns were sign
rather than zero extended (see PR39092). This patch simply adds an explicit
signext to the returns in imm.ll.
Further optimisations for constant materialisation are possible, most notably
for mask-like values which can be generated my loading -1 and shifting right.
A future patch will standardise on the C++ codepath for immediate selection on
RV32 as well as RV64, and then add further such optimisations to
RISCVMatInt::generateInstSeq in order to benefit both RV32 and RV64 for
codegen and li expansion.
Differential Revision: https://reviews.llvm.org/D52962
llvm-svn: 347042
C.EBREAK was defined with hasSideEffects = 0, which is incorrect and
inconsistent with the non-compressed instruction form. This patch corrects
this oversight.
This wouldn't cause codegen issues, as compressed instructions are only ever
generated by converting the non-compressed form as an MCInst. But having
correct flags is still worthwhile.
Differential Revision: https://reviews.llvm.org/D54256
Patch by Luís Marques.
llvm-svn: 346959
Mark the FREM SelectionDAG node as Expand, which is necessary in order to
support the frem IR instruction on RISC-V. This is expanded into a library
call. Adds the corresponding test. Previously, this would have triggered an
assertion at instruction selection time.
Differential Revision: https://reviews.llvm.org/D54159
Patch by Luís Marques.
llvm-svn: 346958
Logic to load 32-bit and 64-bit immediates is currently present in
RISCVAsmParser::emitLoadImm in order to support the li pseudoinstruction. With
the introduction of RV64 codegen, there is a greater benefit of sharing
immediate materialisation logic between the MC layer and codegen. The
generateInstSeq helper allows this by producing a vector of simple structs
representing the chosen instructions. This can then be consumed in the MC
layer to produce MCInsts or at instruction selection time to produce
appropriate SelectionDAG node. Sharing this logic means that both the li
pseudoinstruction and codegen can benefit from future optimisations, and
that this logic can be used for materialising constants during RV64 codegen.
This patch does contain a behaviour change: addi will now be produced on RV64
when no lui is necessary to materialise the constant. In that case addiw takes
x0 as the source register, so is semantically identical to addi.
Differential Revision: https://reviews.llvm.org/D52961
llvm-svn: 346937
This extends the .option support from D45864 to enable/disable the relax
feature flag from D44886
During parsing of the relax/norelax directives, the RISCV::FeatureRelax
feature bits of the SubtargetInfo stored in the AsmParser are updated
appropriately to reflect whether relaxation is currently enabled in the
parser. When an instruction is parsed, the parser checks if relaxation is
currently enabled and if so, gets a handle to the AsmBackend and sets the
ForceRelocs flag. The AsmBackend uses a combination of the original
RISCV::FeatureRelax feature bits set by e.g -mattr=+/-relax and the
ForceRelocs flag to determine whether to emit relocations for symbol and
branch diffs. Diff relocations should therefore only not be emitted if the
relax flag was not set on the command line and no instruction was ever parsed
in a section with relaxation enabled to ensure correct diffs are emitted.
Differential Revision: https://reviews.llvm.org/D46423
Patch by Lewis Revill.
llvm-svn: 346655
A number of intrinsics, such as llvm.sin.f32, would result in a failure to
select. This patch adds expansions for the relevant selection DAG nodes, as
well as exhaustive testing for all f32 and f64 intrinsics.
The codegen for FMA remains a TODO item, pending support for the various
RISC-V FMA instruction variants.
The llvm.minimum.f32.* and llvm.maximum.* tests are commented-out, pending
upstream support for target-independent expansion, as discussed in
http://lists.llvm.org/pipermail/llvm-dev/2018-November/127408.html.
Differential Revision: https://reviews.llvm.org/D54034
Patch by Luís Marques.
llvm-svn: 346034
SelectionDAGBuilder::visitShift will always zero-extend a shift amount when it
is promoted to the ShiftAmountTy. This results in zero-extension (masking)
which is unnecessary for RISC-V as the shift operations only read the lower 5
or 6 bits (RV32 or RV64).
I initially proposed adding a getExtendForShiftAmount hook so the shift amount
can be any-extended (D52975). @efriedma explained this was unsafe, so I have
instead eliminate the unnecessary and operations at instruction selection time
in a manner similar to X86InstrCompiler.td.
Differential Revision: https://reviews.llvm.org/D53224
llvm-svn: 344432
Summary:
Instruction with 0 in fence field being disassembled as fence , iorw.
Printing "unknown" to match GAS behavior.
This bug was uncovered by a LLVM MC Disassembler Protocol Buffer Fuzzer
for the RISC-V assembly language.
Reviewers: asb
Subscribers: rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, jfb, PkmX, jocewei, asb
Differential Revision: https://reviews.llvm.org/D51828
llvm-svn: 344309
A pattern was present for addi rd, x0, simm6 but not addiw which is
semantically identical when the source register is x0. This patch addresses
that, and the benefit can be seen in rv64c-aliases-valid.s.
llvm-svn: 343911
lowerGlobalAddress, lowerBlockAddress, and insertIndirectBranch contain
overzealous checks for is64Bit. These functions are all safe as-implemented
for RV64.
llvm-svn: 343781
f32 values passed on the stack would previously cause an assertion in
unpackFromMemLoc.. This would only trigger in the presence of the F extension
making f32 a legal type. Otherwise the f32 would be legalized.
This patch fixes that by keeping LocVT=f32 when a float is passed on the
stack. It also adds test coverage for this case, and tests that also
demonstrate lw/sw/flw/fsw will be selected when most profitable. i.e. there is
no unnecessary i32<->f32 conversion in registers.
llvm-svn: 343756
r343712 performed this optimisation during instruction selection. As Eli
Friedman pointed out in post-commit review, implementing this as a DAGCombine
might allow opportunities for further optimisations.
llvm-svn: 343741
There was some duplicated logic for using the LocInfo of a CCValAssign in
order to convert from the ValVT to LocVT or vice versa. Resolve this by
factoring out convertLocVTFromValVT from unpackFromRegLoc. Also rename
packIntoRegLoc to the more appropriate convertValVTToLocVT and call these
helper functions consistently.
llvm-svn: 343737
Although we can't write a tablegen pattern to remove redundant
splitf64+buildf64 pairs due to the multiple return values, we can handle it
with some C++ selection code. This is simpler than removing them after
instruction selection through RISCVDAGToDAGISel::PostprocessISelDAG, as was
done previously.
llvm-svn: 343712
The patterns as defined are correct only when XLen==32.
This is another preparatory patch for a set of patches that flesh out RV64
codegen.
llvm-svn: 343679
1. brcond operates on an condition.
2. atomic_fence and the pseudo AMO instructions should all take xlen immediates
This allows the same definitions and patterns to work for RV64 (XLenVT==i64).
llvm-svn: 343678
This is a trivial refactoring that I'm committing now as it makes a patch I'm
about to post for review easier to follow. There is some overlap between
evaluateConstantImm and addExpr in RISCVAsmParser. This patch allows
evaluateConstantImm to be reused from addExpr to remove this overlap. The
benefit will be greater when a future patch adds extra code to allows
immediates to be evaluated from constant symbols (e.g. `.equ CONST, 0x1234`).
No functional change intended.
llvm-svn: 342641
Examples such as `jal a3`, `j a3` and `jal a3, a3` are accepted by gas
but rejected by LLVM MC. This patch rectifies this. I introduce
RISCVAsmParser::parseJALOffset to ensure that symbol names that coincide with
register names can safely be parsed. This is made a somewhat fiddly due to the
single-operand alias form (see the comment in parseJALOffset for more info).
Differential Revision: https://reviews.llvm.org/D52029
llvm-svn: 342629
Introduce a new RISCVExpandPseudoInsts pass to expand atomic
pseudo-instructions after register allocation. This is necessary in order to
ensure that register spills aren't introduced between LL and SC, thus breaking
the forward progress guarantee for the operation. AArch64 does something
similar for CmpXchg (though only at O0), and Mips is moving towards this
approach (see D31287). See also [this mailing list
post](http://lists.llvm.org/pipermail/llvm-dev/2016-May/099490.html) from
James Knight, which summarises the issues with lowering to ll/sc in IR or
pre-RA.
See the [accompanying RFC
thread](http://lists.llvm.org/pipermail/llvm-dev/2018-June/123993.html) for an
overview of the lowering strategy.
Differential Revision: https://reviews.llvm.org/D47882
llvm-svn: 342534
This allows the hard-coded shouldForceImmediate logic to be removed because
the generated MatchOperandParserImpl makes use of the current context (i.e.
the current mnemonic) to determine parsing behaviour, and so won't first try
to parse a register before parsing a symbol name.
No functional change is intended. gas accepts immediate arguments for call,
tail and lla. This patch doesn't address this discrepancy.
Differential Revision: https://reviews.llvm.org/D51733
llvm-svn: 342488
addi a0, a0, foo and lw a0, foo(a0) and similar are now rejected. An explicit
%lo and %pcrel_lo modifier is required. This matches gas behaviour.
llvm-svn: 342487
Reject bare symbols and accept only %pcrel_hi(sym) for auipc and %hi(sym) for
lui. Also test valid operand modifiers in rv32i-valid.s.
Note this is slightly stricter than gas, which will accept either %pcrel_hi or
%hi for both lui and auipc.
Differential Revision: https://reviews.llvm.org/D51731
llvm-svn: 342486
Summary:
Fixed assertions due to invalid fixup when encoding compressed instructions
(c.addi, c.addiw, c.li, c.andi) with bare symbols with/without modifiers.
This matches GAS behavior as well.
This bug was uncovered by a LLVM MC Disassembler Protocol Buffer Fuzzer
for the RISC-V assembly language.
Reviewers: asb
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, asb
Differential Revision: https://reviews.llvm.org/D52005
llvm-svn: 342160
Summary:
The illegal instruction 0x00 0x00 is being wrongly decoded as
c.addi4spn with 0 immediate.
The invalid instruction 0x01 0x61 is being wrongly decoded as
c.addi16sp with 0 immediate.
This bug was uncovered by a LLVM MC Disassembler Protocol Buffer Fuzzer
for the RISC-V assembly language.
Reviewers: asb
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, asb
Differential Revision: https://reviews.llvm.org/D51815
llvm-svn: 342159
Disassemblers cannot depend on main target headers. The same is true for
MCTargetDesc, but there's a lot more cleanup needed for that.
llvm-svn: 341822
Summary:
RISCVDisassembler should check number of bytes available before reading them.
Crash noticed when enabling -DLLVM_USE_SANITIZER=Address.
This bug was uncovered by a LLVM MC Disassembler Protocol Buffer Fuzzer for the RISC-V assembly language.
Reviewers: asb
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, asb
Differential Revision: https://reviews.llvm.org/D51708
llvm-svn: 341686
Summary:
RISCVAsmParser needs to handle the case the error message is of specific type, other than the generic Match_InvalidOperand, and the corresponding
operand is missing.
This bug was uncovered by a LLVM MC Assembler Protocol Buffer Fuzzer for the RISC-V assembly language.
Reviewers: asb
Reviewed By: asb
Subscribers: llvm-commits, jocewei, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX
Differential Revision: https://reviews.llvm.org/D50790
llvm-svn: 341104
We cannot directy reuse the patterns of StPat because for some reason the store
DAG node and the atomic_store_nn DAG nodes put the ptr and the value in
different positions. Currently we attempt to store the address to an address
formed by the value.
Differential Revision: https://reviews.llvm.org/D51217
llvm-svn: 340722
This function is not virtual, it is private and it is not called anywhere. No
regression is introduced by removing it.
I think we can safely remove it.
Differential Revision: https://reviews.llvm.org/D50836
llvm-svn: 340024
This is a fix for r339314.
MCInstBuilder uses the named parameter idiom and an 'operator MCInst&' to ease
the creation of MCInsts. As the object of MCInstBuilder owns the MCInst is
manipulating, the lifetime of the MCInst is bound to that of MCInstBuilder.
In r339314 I bound a reference to the MCInst in an initializer. The
temporary of MCInstBuilder (and also its MCInst) is destroyed at the end of
the declaration leading to a dangling reference.
Fix this by using MCInstBuilder inside an argument of a function call.
Temporaries in function calls are destroyed in the enclosing full expression,
so the the reference to MCInst is still valid when emitToStreamer executes.
llvm-svn: 339654
This pseudo-instruction is similar to la but uses PC-relative addressing
unconditionally. This is, la is only different to lla when using -fPIC. This
pseudo-instruction seems often forgotten in several specs but it is definitely
mentioned in binutils opcodes/riscv-opc.c. The semantics are defined both in
page 37 of the "RISC-V Reader" book but also in function macro found in
gas/config/tc-riscv.c.
This is a very first step towards adding PIC support for Linux in the RISC-V
backend.
The lla pseudo-instruction expands to a sequence of auipc + addi with a couple
of pc-rel relocations where the second points to the first one. This is
described in
https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md#pc-relative-symbol-addresses
For now, this patch only introduces support of that pseudo instruction at the
assembler parser.
Differential Revision: https://reviews.llvm.org/D49661
llvm-svn: 339314
Match the GNU assembler in supporting immediate operands for these
instructions even when the reg-reg mnemonic is used.
Differential Revision: https://reviews.llvm.org/D50046
Patch by Kito Cheng.
llvm-svn: 339252
- Save/restore only registers that are used.
This includes Callee saved registers and Caller saved registers
(arguments and temporaries) for integer and FP registers.
- If there is a call in the interrupt handler, save/restore all
Caller saved registers (arguments and temporaries) and all FP registers.
- Emit special return instructions depending on "interrupt"
attribute type.
Based on initial patch by Zhaoshi Zheng.
Reviewers: asb
Reviewed By: asb
Subscribers: rkruppe, the_o, MartinMosbeck, brucehoult, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, llvm-commits
Differential Revision: https://reviews.llvm.org/D48411
llvm-svn: 338047
Summary:
In r333455 we added a peephole to fix the corner cases that result
from separating base + offset lowering of global address.The
peephole didn't handle some of the cases because it only has a basic
block view instead of a function level view.
This patch replaces that logic with a machine function pass. In
addition to handling the original cases it handles uses of the global
address across blocks in function and folding an offset from LW\SW
instruction. This pass won't run for OptNone compilation, so there
will be a negative impact overall vs the old approach at O0.
Reviewers: asb, apazos, mgrang
Reviewed By: asb
Subscribers: MartinMosbeck, brucehoult, the_o, rogfer01, mgorny, rbar, johnrusso, simoncook, niosHD, kito-cheng, shiva0217, zzheng, llvm-commits, edward-jones
Differential Revision: https://reviews.llvm.org/D47857
llvm-svn: 335786
Summary:
When expanding the PseudoTail in expandFunctionCall() we were using X6
to save the return address. Since this is a tail call the return
address is not needed, this patch replaces it with X0 to be ignored.
This matches the behaviour listed in the ISA V2.2 document page 110.
tail offset -----> jalr x0, x6, offset
GCC exhibits the same behavior.
Reviewers: apazos, asb, mgrang
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01
Differential Revision: https://reviews.llvm.org/D48343
llvm-svn: 335239
These instructions were renamed in version 2.2 of the user-level ISA spec, but
the old name should also be accepted by standard tools.
llvm-svn: 335154
These are produced by GCC and supported by GAS, but not currently contained in
the pseudoinstruction listing in the RISC-V ISA manual.
llvm-svn: 335127
These are produced by GCC and supported by GAS, but not currently contained in
the pseudoinstruction listing in the RISC-V ISA manual.
llvm-svn: 335120
Fences are inserted according to table A.6 in the current draft of version 2.3
of the RISC-V Instruction Set Manual, which incorporates the memory model
changes and definitions contributed by the RISC-V Memory Consistency Model
task group.
Instruction selection failures will now occur for 8/16/32-bit atomicrmw and
cmpxchg operations when targeting RV32IA until lowering for these operations
is added in a follow-on patch.
Differential Revision: https://reviews.llvm.org/D47589
llvm-svn: 334591
This patch adds lowering for atomic fences and relies on AtomicExpandPass to
lower atomic loads/stores, atomic rmw, and cmpxchg to __atomic_* libcalls.
test/CodeGen/RISCV/atomic-* are modelled on the exhaustive
test/CodeGen/PPC/atomics-regression.ll, and will prove more useful once RV32A
codegen support is introduced.
Fence mappings are taken from table A.6 in the current draft of version 2.3 of
the RISC-V Instruction Set Manual, which incorporates the memory model changes
and definitions contributed by the RISC-V Memory Consistency Model task group.
Differential Revision: https://reviews.llvm.org/D47587
llvm-svn: 334590
The instruction makes use of a previously ignored field in the fence
instruction. It is introduced in the version 2.3 draft of the RISC-V
specification after much work by the Memory Model Task Group.
As clarified here <https://github.com/riscv/riscv-isa-manual/issues/186>,
the fence.tso assembler mnemonic does not have operands.
llvm-svn: 334278
The implementation follows the MIPS backend and expands the pseudo instruction
directly during asm parsing. As the result, only real MC instructions are
emitted to the MCStreamer. The actual expansion to real instructions is
similar to the expansion performed by the GNU Assembler.
This patch supersedes D41949.
Differential Revision: https://reviews.llvm.org/D46118
Patch by Mario Werner.
llvm-svn: 334203
Summary:
They've been deprecated in favor of UADDO/ADDCARRY or USUBO/SUBCARRY for a while.
Target that uses these opcodes are changed in order to ensure their behavior doesn't change.
Reviewers: efriedma, craig.topper, dblaikie, bkramer
Subscribers: jholewinski, arsenm, jyknight, sdardis, nemanjai, nhaehnle, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, mgrang, atanasyan, llvm-commits
Differential Revision: https://reviews.llvm.org/D47422
llvm-svn: 333748
Resolving fixup_riscv_call by assembler when the linker relaxation diabled
and the function and callsite within the same compile unit.
And also adding static_assert after Infos array declaration
to avoid missing any new fixup in MCFixupKindInfo in the future.
Differential Revision: https://reviews.llvm.org/D47126
llvm-svn: 333487
Summary:
Base and offset are always separated when a GlobalAddress node is lowered
(rL332641) as an optimization to reduce instruction count. However, this
optimization is not profitable if the Global Address ends up being used in only
instruction.
This patch adds peephole optimizations that merge an offset of
an address calculation into the LUI %%hi and ADD %lo of the lowering sequence.
The peephole handles three patterns:
1) ADDI (ADDI (LUI %hi(global)) %lo(global)), offset
--->
ADDI (LUI %hi(global + offset)) %lo(global + offset).
This generates:
lui a0, hi (global + offset)
add a0, a0, lo (global + offset)
Instead of
lui a0, hi (global)
addi a0, hi (global)
addi a0, offset
This pattern is for cases when the offset is small enough to fit in the
immediate filed of ADDI (less than 12 bits).
2) ADD ((ADDI (LUI %hi(global)) %lo(global)), (LUI hi_offset))
--->
offset = hi_offset << 12
ADDI (LUI %hi(global + offset)) %lo(global + offset)
Which generates the ASM:
lui a0, hi(global + offset)
addi a0, lo(global + offset)
Instead of:
lui a0, hi(global)
addi a0, lo(global)
lui a1, (offset)
add a0, a0, a1
This pattern is for cases when the offset doesn't fit in an immediate field
of ADDI but the lower 12 bits are all zeros.
3) ADD ((ADDI (LUI %hi(global)) %lo(global)), (ADDI lo_offset, (LUI hi_offset)))
--->
offset = global + offhi20<<12 + offlo12
ADDI (LUI %hi(global + offset)) %lo(global + offset)
Which generates the ASM:
lui a1, %hi(global + offset)
addi a1, %lo(global + offset)
Instead of:
lui a0, hi(global)
addi a0, lo(global)
lui a1, (offhi20)
addi a1, (offlo12)
add a0, a0, a1
This pattern is for cases when the offset doesn't fit in an immediate field
of ADDI and both the lower 1 bits and high 20 bits are non zero.
Reviewers: asb
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, apazos,
niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang
llvm-svn: 333455
To do this:
1. Add fixup_riscv_relax fixup types which eventually will
transfer to R_RISCV_RELAX relocation types.
2. Insert R_RISCV_RELAX relocation types to auipc function call
expression when linker relaxation enabled.
Differential Revision: https://reviews.llvm.org/D44886
llvm-svn: 333158
Summary:
Set CostPerUse higher for registers that are not used in the compressed
instruction set. This will influence the greedy register allocator to reduce
the use of registers that can't be encoded in 16 bit instructions. This
affects register allocation even when compressed instruction isn't targeted,
we see no major negative codegen impact.
Reviewers: asb
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, apazos, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang
Differential Revision: https://reviews.llvm.org/D47039
llvm-svn: 333132
For RISC-V it is desirable to have relaxation happen in the linker once
addresses are known, and as such the size between two instructions/byte
sequences in a section could change.
For most assembler expressions, this is fine, as the absolute address results
in the expression being converted to a fixup, and finally relocations.
However, for expressions such as .quad .L2-.L1, the assembler folds this down
to a constant once fragments are laid out, under the assumption that the
difference can no longer change, although in the case of linker relaxation the
differences can change at link time, so the constant is incorrect. One place
where this commonly appears is in debug information, where the size of a
function expression is in a form similar to the above.
This patch extends the assembler to allow an AsmBackend to declare that it
does not want the assembler to fold down this expression, and instead generate
a pair of relocations that allow the linker to carry out the calculation. In
this case, the expression is not folded, but when it comes to emitting a
fixup, the generic FK_Data_* fixups are converted into a pair, one for the
addition half, one for the subtraction, and this is passed to the relocation
generating methods as usual. I have named these FK_Data_Add_* and
FK_Data_Sub_* to indicate which half these are for.
For RISC-V, which supports this via e.g. the R_RISCV_ADD64, R_RISCV_SUB64 pair
of relocations, these are also set to always emit relocations relative to
local symbols rather than section offsets. This is to deal with the fact that
if relocations were calculated on e.g. .text+8 and .text+4, the result 12
would be stored rather than 4 as both addends are added in the linker.
Differential Revision: https://reviews.llvm.org/D45181
Patch by Simon Cook.
llvm-svn: 333079
This is a different approach to fixing the problem described in D46746.
RISCVAsmBackend currently depends on the getSize helper function returning the
number of bytes a fixup may change (note: some other backends have a similar
helper named getFixupNumKindBytes). As noted in that review, this doesn't
return the correct size for FK_Data_1, FK_Data_2, or FK_Data_8 meaning that
too few bytes will be written in the case of FK_Data_8, and there's the
potential of writing outside the Data array for the smaller fixups.
D46746 extends getSize to recognise some of the builtin fixup types. Rather
than having a function that needs to be kept up to date as new builtin or
target-specific fixups are added, We can calculate an appropriate bound on the
number of bytes that might be touched using Info.TargetSize and
Info.TargetOffset.
Differential Revision: https://reviews.llvm.org/D46965
llvm-svn: 333076
With this we gain a little flexibility in how the generic object
writer is created.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47045
llvm-svn: 332868
To make this work I needed to add an endianness field to MCAsmBackend
so that writeNopData() implementations know which endianness to use.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47035
llvm-svn: 332857
Provide some free functions to reduce verbosity of endian-writing
a single value, and replace the endianness template parameter with
a field.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47032
llvm-svn: 332757
For RISCV branch instructions, we need to preserve relocation types when linker
relaxation enabled, so then linker could modify offset when the branch offsets
changed.
We preserve relocation types by define shouldForceRelocation.
IsResolved return by evaluateFixup will always false when shouldForceRelocation
return true. It will make RISCV MC Branch Relaxation always relax 16-bit
branches to 32-bit form, even if the symbol actually could be resolved.
To avoid 16-bit branches always relax to 32-bit form when linker relaxation
enabled, we add a new parameter WasForced to indicate that the symbol actually
couldn't be resolved and not forced by shouldForceRelocation return true.
RISCVAsmBackend::fixupNeedsRelaxationAdvanced could relax branches with
unresolved symbols by (!IsResolved && !WasForced).
RISCV MC Branch Relaxation is needed because RISCV could perform 32-bit
to 16-bit transformation in MC layer.
Differential Revision: https://reviews.llvm.org/D46350
llvm-svn: 332696
Summary:
When lowering global address, lower the base as a TargetGlobal first then
create an SDNode for the offset separately and chain it to the address calculation
This optimization will create a DAG where the base address of a global access will
be reused between different access. The offset can later be folded into the immediate
part of the memory access instruction.
With this optimization we generate:
lui a0, %hi(s)
addi a0, a0, %lo(s) ; shared base address.
addi a1, zero, 20 ; 2 instructions per access.
sw a1, 44(a0)
addi a1, zero, 10
sw a1, 8(a0)
addi a1, zero, 30
sw a1, 80(a0)
Instead of:
lui a0, %hi(s+44) ; 3 instructions per access.
addi a1, zero, 20
sw a1, %lo(s+44)(a0)
lui a0, %hi(s+8)
addi a1, zero, 10
sw a1, %lo(s+8)(a0)
lui a0, %hi(s+80)
addi a1, zero, 30
sw a1, %lo(s+80)(a0)
Which will save one instruction per access.
Reviewers: asb, apazos
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, apazos, asb, llvm-commits
Differential Revision: https://reviews.llvm.org/D46989
llvm-svn: 332641
Summary:
This patch implements MC support for tail psuedo instruction.
A follow-up patch implements the codegen support as well as handling of the indirect tail pseudo instruction.
Reviewers: asb, apazos
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, llvm-commits
Differential Revision: https://reviews.llvm.org/D46221
llvm-svn: 332634
The isReMaterlizable flag is somewhat confusing, unlike most other instruction
flags it is currently interpreted as a hint (mightBeRematerializable would be
a better name). While LUI is always rematerialisable, for an instruction like
ADDI it depends on its operands. TargetInstrInfo::isTriviallyReMaterializable
will call TargetInstrInfo::isReallyTriviallyReMaterializable, which in turn
calls TargetInstrInfo::isReallyTriviallyReMaterializableGeneric. We rely on
the logic in the latter to pick out instances of ADDI that really are
rematerializable.
The isReMaterializable flag does make a difference on a variety of test
programs. The recently committed remat.ll test case demonstrates how stack
usage is reduce and a unnecessary lw/sw can be removed. Stack usage in the
Proc0 function in dhrystone reduces from 192 bytes to 112 bytes.
For the sake of completeness, this patch also implements
RISCVRegisterInfo::isConstantPhysReg. Although this is called from a number of
places, it doesn't seem to result in different codegen for any programs I've
thrown at it. However, it is called in the rematerialisation codepath and it
seems sensible to implement something correct here.
Differential Revision: https://reviews.llvm.org/D46182
llvm-svn: 332617
These directives are recognised by gas. Support is added through the use of
addAliasForDirective.
Also match RISC-V gcc in preferring .half and .word for 16-bit and 32-bit data
directives.
llvm-svn: 332574
1. Deine FeatureRelax to enable/disable linker relaxation.
2. Define shouldForceRelocation to preserve relocation types even if the fixup
can be resolved when linker relaxation enabled. This is necessary for
correctness as offsets may change during relaxation.
Differential Revision: https://reviews.llvm.org/D46674
llvm-svn: 332318
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
These directives allow the 'C' (compressed) extension to be enabled/disabled
within a single file.
Differential Revision: https://reviews.llvm.org/D45864
Patch by Kito Cheng
llvm-svn: 332107
Inspired by r331508, I did a grep and found these.
Mostly just change from dyn_cast to cast. Some cases also showed a dyn_cast result being converted to bool, so those I changed to isa.
llvm-svn: 331577
This causes some slight shuffling but no meaningful codegen differences on the
corpus I used for testing, but it has a larger impact when combined with e.g.
rematerialisation. Regardless, it makes sense to report as accurate
target-specific information as possible.
llvm-svn: 330949
I'm unable to construct a representative test case that demonstrates the
advantage, but it seems sensible to report accurate target-specific
information regardless.
llvm-svn: 330938
This has no impact on codegen for the current RISC-V unit tests or my small
benchmark set and very minor changes in a few programs in the GCC torture
suite. Based on this, I haven't been able to produce a representative test
program that demonstrates a benefit from isLegalAddressingMode. I'm committing
the patch anyway, on the basis that presenting accurate information to the
target-independent code is preferable to relying on incorrect generic
assumptions.
llvm-svn: 330932
Previously `call zero`, `call f0` etc would fail. This leads to compilation
failures if building programs that define functions with those names and using
-save-temps.
llvm-svn: 330846
To do this:
1. Change GlobalAddress SDNode to TargetGlobalAddress to avoid legalizer
split the symbol.
2. Change ExternalSymbol SDNode to TargetExternalSymbol to avoid legalizer
split the symbol.
3. Let PseudoCALL match direct call with target operand TargetGlobalAddress
and TargetExternalSymbol.
Differential Revision: https://reviews.llvm.org/D44885
llvm-svn: 330827
To do this:
1. Add PseudoCALLIndirct to match indirect function call.
2. Add PseudoCALL to support parsing and print pseudo `call` in assembly
3. Expand PseudoCALL to the following form with R_RISCV_CALL relocation type
while encoding:
auipc ra, func
jalr ra, ra, 0
If we expand PseudoCALL before emitting assembly, we will see auipc and jalr
pair when compile with -S. It's hard for assembly parser to parsing this
pair and identify it's semantic is function call and then insert R_RISCV_CALL
relocation type. Although we could insert R_RISCV_PCREL_HI20 and
R_RISCV_PCREL_LO12_I relocation types instead of R_RISCV_CALL.
Due to RISCV relocation design, auipc and jalr pair only can relax to jal with
R_RISCV_CALL + R_RISCV_RELAX relocation types.
We expand PseudoCALL as late as encoding(RISCVMCCodeEmitter) instead of before
emitting assembly(RISCVAsmPrinter) because we want to preserve call
pseudoinstruction in assembly code. It's more readable and assembly parser
could identify call assembly and insert R_RISCV_CALL relocation type.
Differential Revision: https://reviews.llvm.org/D45859
llvm-svn: 330826
Reverts rL330224, while issues with the C extension and missed common
subexpression elimination opportunities are addressed. Neither of these issues
are visible in current RISC-V backend unit tests, which clearly need
expanding.
llvm-svn: 330281
The implementation follows the MIPS backend and expands the
pseudo instruction directly during asm parsing. As the result, only
real MC instructions are emitted to the MCStreamer. Additionally,
PseudoLI instructions are emitted during codegen. The actual
expansion to real instructions is performed during MI to MC lowering
and is similar to the expansion performed by the GNU Assembler.
Differential Revision: https://reviews.llvm.org/D41949
Patch by Mario Werner.
llvm-svn: 330224
Summary:
Specifying assert message with an || operator makes the compiler interpret it
as a bool. Changed it to &&.
Reviewers: asb, apazos
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, llvm-commits
Differential Revision: https://reviews.llvm.org/D45660
llvm-svn: 330148
Summary:
GCC compresses the pseudo instruction "mv rd, rs", which is an alias of
"addi rd, rs, 0", to "c.mv rd, rs".
In LLVM we rely on the canonical MC instruction (MCInst) to do our compression
checks and since there is no rule to compress "addi rd, rs, 0" --> "c.mv
rd, rs" we lose this compression opportunity to gcc.
In this patch we fix that by adding an addi to c.mv compression pattern, the
instruction "mv rd, rs" will be compressed to "c.mv rd, rs" just like
gcc does.
Patch by Zhaoshi Zheng (zzheng) and Sameer (sabuasal).
Reviewers: asb, apazos, zzheng, mgrang, shiva0217
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, niosHD, kito-cheng, llvm-commits
Differential Revision: https://reviews.llvm.org/D45583
llvm-svn: 329939
Summary:
According RISC-V ELF psABI specification, base RV32 and RV64 ISAs only
allow 32-bit instruction alignment, but instruction allow to be aligned
to 16-bit boundaries for C-extension.
So we just align to 4 bytes and 2 bytes for C-extension is enough.
Reviewers: asb, apazos
Differential Revision: https://reviews.llvm.org/D45560
Patch by Kito Cheng.
llvm-svn: 329899
Also add double-prevoius-failure.ll which captures a test case that at one
point triggered a compiler crash, while developing calling convention support
for f64 on RV32D with soft-float ABI.
llvm-svn: 329877
fadd.d is required in order to force floating point registers to be used in
test code, as parameters are passed in integer registers in the soft float
ABI.
Much of this patch is concerned with support for passing f64 on RV32D with a
soft-float ABI. Similar to Mips, introduce pseudoinstructions to build an f64
out of a pair of i32 and to split an f64 to a pair of i32. BUILD_PAIR and
EXTRACT_ELEMENT can't be used, as a BITCAST to i64 would be necessary, but i64
is not a legal type.
llvm-svn: 329871
Summary:
This patch implements a tablegen-driven Instruction Compression
mechanism for generating RISCV compressed instructions
(C Extension) from the expanded instruction form.
This tablegen backend processes CompressPat declarations in a
td file and generates all the compile-time and runtime checks
required to validate the declarations, validate the input
operands and generate correct instructions.
The checks include validating register operands, immediate
operands, fixed register operands and fixed immediate operands.
Example:
class CompressPat<dag input, dag output> {
dag Input = input;
dag Output = output;
list<Predicate> Predicates = [];
}
let Predicates = [HasStdExtC] in {
def : CompressPat<(ADD GPRNoX0:$rs1, GPRNoX0:$rs1, GPRNoX0:$rs2),
(C_ADD GPRNoX0:$rs1, GPRNoX0:$rs2)>;
}
The result is an auto-generated header file
'RISCVGenCompressEmitter.inc' which exports two functions for
compressing/uncompressing MCInst instructions, plus
some helper functions:
bool compressInst(MCInst& OutInst, const MCInst &MI,
const MCSubtargetInfo &STI,
MCContext &Context);
bool uncompressInst(MCInst& OutInst, const MCInst &MI,
const MCRegisterInfo &MRI,
const MCSubtargetInfo &STI);
The clients that include this auto-generated header file and
invoke these functions can compress an instruction before emitting
it, in the target-specific ASM or ELF streamer, or can uncompress
an instruction before printing it, when the expanded instruction
format aliases is favored.
The following clients were added to implement compression\uncompression
for RISCV:
1) RISCVAsmParser::MatchAndEmitInstruction:
Inserted a call to compressInst() to compresses instructions
parsed by llvm-mc coming from an ASM input.
2) RISCVAsmPrinter::EmitInstruction:
Inserted a call to compressInst() to compress instructions that
were lowered from Machine Instructions (MachineInstr).
3) RVInstPrinter::printInst:
Inserted a call to uncompressInst() to print the expanded
version of the instruction instead of the compressed one (e.g,
add s0, s0, a5 instead of c.add s0, a5) when -riscv-no-aliases
is not passed.
This patch squashes D45119, D42780 and D41932. It was reviewed in smaller patches by
asb, efriedma, apazos and mgrang.
Reviewers: asb, efriedma, apazos, llvm-commits, sabuasal
Reviewed By: sabuasal
Subscribers: mgorny, eraman, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, niosHD, kito-cheng, shiva0217, zzheng
Differential Revision: https://reviews.llvm.org/D45385
llvm-svn: 329455
Makes it easier to see mistakes such as the one fixed in r329178 and makes
the different target CMakeLists more consistent.
Also remove some stale-looking comments from the Nios2 target cmakefile.
No intended behavior change.
llvm-svn: 329181
Currently EVT is in the IR layer only because of Function.cpp needing a very small piece of the functionality of EVT::getEVTString(). The rest of EVT is used in codegen making CodeGen a better place for it.
The previous code converted a Type* to EVT and then called getEVTString. This was only expected to handle the primitive types from Type*. Since there only a few primitive types, we can just print them as strings directly.
Differential Revision: https://reviews.llvm.org/D45017
llvm-svn: 328806
Summary:
LLVM defaults to the newer .init_array/.fini_array scheme for static
constructors rather than the less desirable .ctors/.dtors (the UseCtors
flag defaults to false). This wasn't being respected in the RISC-V
backend because it fails to call TargetLoweringObjectFileELF::InitializeELF with the the appropriate
flag for UseInitArray.
This patch fixes this by implementing RISCVELFTargetObjectFile and overriding its Initialize method to call
InitializeELF(TM.Options.UseInitArray).
Reviewers: asb, apazos
Reviewed By: asb
Subscribers: mgorny, rbar, johnrusso, simoncook, jordy.potman.lists, sabuasal, niosHD, kito-cheng, shiva0217, llvm-commits
Differential Revision: https://reviews.llvm.org/D44750
llvm-svn: 328433
This patch also includes extensive tests targeted at select and br+fcmp IR
inputs. A sequence of br+fcmp required support for FPR32 registers to be added
to RISCVInstrInfo::storeRegToStackSlot and
RISCVInstrInfo::loadRegFromStackSlot.
llvm-svn: 328104
E.g.
bar (int x)
{
char p[x];
push outgoing variables for foo.
call foo
}
We need to generate stack adjustment instructions for outgoing arguments by
eliminateCallFramePseudoInstr when the function contains variable size
objects to avoid outgoing variables corrupt the variable size object.
Default hasReservedCallFrame will return !hasFP().
We don't want to generate extra sp adjustment instructions when hasFP()
return true, So We override hasReservedCallFrame as !hasVarSizedObjects().
Differential Revision: https://reviews.llvm.org/D43752
llvm-svn: 327938
Summary:
This patch implements relaxation for RISCV in the MC layer.
The following relaxations are currently handled:
1) Relax C_BEQZ to BEQ and C_BNEZ to BNEZ in RISCV.
2) Relax and C_J $imm to JAL x0, $imm and CJAL to JAL ra, $imm.
Reviewers: asb, llvm-commits, efriedma
Reviewed By: asb
Subscribers: shiva0217
Differential Revision: https://reviews.llvm.org/D43055
llvm-svn: 326626
Summary:
Add a target option AllowRegisterRenaming that is used to opt in to
post-register-allocation renaming of registers. This is set to 0 by
default, which causes the hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq
fields of all opcodes to be set to 1, causing
MachineOperand::isRenamable to always return false.
Set the AllowRegisterRenaming flag to 1 for all in-tree targets that
have lit tests that were effected by enabling COPY forwarding in
MachineCopyPropagation (AArch64, AMDGPU, ARM, Hexagon, Mips, PowerPC,
RISCV, Sparc, SystemZ and X86).
Add some more comments describing the semantics of the
MachineOperand::isRenamable function and how it is set and maintained.
Change isRenamable to check the operand's opcode
hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq bit directly instead of
relying on it being consistently reflected in the IsRenamable bit
setting.
Clear the IsRenamable bit when changing an operand's register value.
Remove target code that was clearing the IsRenamable bit when changing
registers/opcodes now that this is done conservatively by default.
Change setting of hasExtraSrcRegAllocReq in AMDGPU target to be done in
one place covering all opcodes that have constant pipe read limit
restrictions.
Reviewers: qcolombet, MatzeB
Subscribers: aemerson, arsenm, jyknight, mcrosier, sdardis, nhaehnle, javed.absar, tpr, arichardson, kristof.beyls, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, niosHD, escha, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D43042
llvm-svn: 325931
Implement c.lui immediate constraint to [1, 31] and [0xfffe0, 0xfffff].
The RISC-V ISA describes the constraint as [1, 63], with that value
being loaded in to bits 17-12 of the destination register and sign extended
from bit 17. Therefore, this 6-bit immediate can represent values in the
ranges [1, 31] and [0xfffe0, 0xfffff].
Differential Revision: https://reviews.llvm.org/D42834
llvm-svn: 325792
As pointed out by @sabuasal in a comment on D23568, the logic in
RISCVMCCodeEmitter::getImmOpValue could be more defensive. Although with the
current instruction definitions it is always the case that `VK_RISCV_LO` is
always used with either an I- or S-format instruction, this may not always be
the case in the future. Add a check to ensure we will get an assertion in
debug builds if that changes.
llvm-svn: 325775
Previously some targets printed their own message at the start of Select to indicate what they were selecting. For the targets that didn't, it means there was no print of the root node before any custom handling in the target executed. So if the target did something custom and never called SelectNodeCommon, no print would be made. For the targets that did print a message in Select, if they didn't custom handle a node SelectNodeCommon would reprint the root node before walking the isel table.
It seems better to just print the message before the call to Select so all targets behave the same. And then remove the root node printing from SelectNodeCommon and just leave a message that says we're starting the table search.
There were also some oddities in blank line behavior. Usually due to a \n after a call to SelectionDAGNode::dump which already inserted a new line.
llvm-svn: 323551
When the compressed instruction set is enabled, the 16-bit c.nop can be
generated if necessary.
Differential Revision: https://reviews.llvm.org/D41221
Patch by Shiva Chen.
llvm-svn: 322658
Although the register scavenger can often find a spare register, an emergency
spill slot is needed to guarantee success. Reserve this slot in cases where
the function is known to have a large stack (meaning the scavenger may be
needed when forming stack addresses).
llvm-svn: 322269
Branch relaxation is needed to support branch displacements that overflow the
instruction's immediate field.
Differential Revision: https://reviews.llvm.org/D40830
llvm-svn: 322224
This is a prerequisite for the branch relaxation pass, and allows a number of
optimisation passes (e.g. BranchFolding and MachineBlockPlacement) to work.
Differential Revision: https://reviews.llvm.org/D40808
llvm-svn: 322222
Includes support for expanding va_copy. Also adds support for using 'aligned'
registers when necessary for vararg calls, and ensure the frame pointer always
points to the bottom of the vararg spill region. This is necessary to ensure
that the saved return address and stack pointer are always available at fixed
known offsets of the frame pointer.
Differential Revision: https://reviews.llvm.org/D40805
llvm-svn: 322215
Currently it's not possible to access MCSubtargetInfo from a TgtMCAsmBackend.
D20830 threaded an MCSubtargetInfo reference through
MCAsmBackend::relaxInstruction, but this isn't the only function that would
benefit from access. This patch removes the Triple and CPUString arguments
from createMCAsmBackend and replaces them with MCSubtargetInfo.
This patch just changes the interface without making any intentional
functional changes. Once in, several cleanups are possible:
* Get rid of the awkward MCSubtargetInfo handling in ARMAsmBackend
* Support 16-bit instructions when valid in MipsAsmBackend::writeNopData
* Get rid of the CPU string parsing in X86AsmBackend and just use a SubtargetFeature for HasNopl
* Emit 16-bit nops in RISCVAsmBackend::writeNopData if the compressed instruction set extension is enabled (see D41221)
This change initially exposed PR35686, which has since been resolved in r321026.
Differential Revision: https://reviews.llvm.org/D41349
llvm-svn: 321692
c.slli/c.srli/c.srai allow a 5-bit shift in RV32C and a 6-bit shift in RV64C.
This patch adds uimmlog2xlennonzero to reflect this constraint as well as
tests.
Differential Revision: https://reviews.llvm.org/D41216
Patch by Shiva Chen.
llvm-svn: 320799
This patch switches the default for -riscv-no-aliases to false
and updates all affected MC and CodeGen tests. As recommended in
D41071, MC tests use the canonical instructions and the CodeGen
tests use the aliases.
Additionally, for the f and d instructions with rounding mode,
the tests for the aliased versions are moved and tightened such
that they can actually detect if alias emission is enabled.
(see D40902 for context)
Differential Revision: https://reviews.llvm.org/D41225
Patch by Mario Werner.
llvm-svn: 320797
Unfortunately these aren't defined explicitly in the privileged spec, but the
GNU assembler does accept `sfence.vma` and `sfence.vma rs` as well as the
usual `sfence.vma rs, rt`.
llvm-svn: 320575
Adds the assembler aliases for the floating point instructions
which can be mapped to a single canonical instruction. The missing
pseudo instructions (flw, fld, fsw, fsd) are marked as TODO. Other
things, like for example PCREL_LO, have to be implemented first.
This patch builds upon D40902.
Differential Revision: https://reviews.llvm.org/D41071
Patch by Mario Werner.
llvm-svn: 320569
When an instruction mnemonic contains a '.', we usually name the instruction
with a _ in that place. e.g. fadd.s -> FADD_S.
This patch updates RISCVInstrInfoC.td to do the same, e.g. c.nop -> C_NOP.
Also includes some minor formatting changes in RISCVInstrInfoC.td to better
align it with the formatting conventions in the rest of the backend.
llvm-svn: 320560
Adds the assembler pseudo instructions of RV32I and RV64I which can
be mapped to a single canonical instruction. The missing pseudo
instructions (e.g., call, tail, ...) are marked as TODO. Other
things, like for example PCREL_LO, have to be implemented first.
Currently, alias emission is disabled by default to keep the patch
minimal. Alias emission by default will be enabled in a subsequent
patch which also updates all affected tests. Note that this patch
should actually break the floating point MC tests. However, the
used FileCheck configuration is not tight enought to detect the
breakage.
Differential Revision: https://reviews.llvm.org/D40902
Patch by Mario Werner.
llvm-svn: 320487
The TableGen-based calling convention definitions are inflexible, while
writing a function to implement the calling convention is very
straight-forward, and allows difficult cases to be handled more easily. With
this patch adds support for:
* Passing large scalars according to the RV32I calling convention
* Byval arguments
* Passing values on the stack when the argument registers are exhausted
The custom CC_RISCV calling convention is also used for returns.
This patch also documents the ABI lowering that a language frontend is
expected to perform. I would like to work to simplify these requirements over
time, but this will require further discussion within the LLVM community.
We add PendingArgFlags CCState, as a companion to PendingLocs.
The PendingLocs vector is used by a number of backends to handle arguments
that are split during legalisation. However CCValAssign doesn't keep track of
the original argument alignment. Therefore, add a PendingArgFlags vector which
can be used to keep track of the ISD::ArgFlagsTy for every value added to
PendingLocs.
Differential Revision: https://reviews.llvm.org/D39898
llvm-svn: 320359
As frame pointer elimination isn't implemented until a later patch and we make
extensive use of update_llc_test_checks.py, this changes touches a lot of the
RISC-V tests.
Differential Revision: https://reviews.llvm.org/D39849
llvm-svn: 320357
Introduces the AddrFI "addressing mode", which is necessary simply because
it's not possible to write a pattern that directly matches a frameindex.
Ensure callee-saved registers are accessed relative to the stackpointer. This
is necessary as callee-saved register spills are performed before the frame
pointer is set.
Move HexagonDAGToDAGISel::isOrEquivalentToAdd to SelectionDAGISel, so we can
make use of it in the RISC-V backend.
Differential Revision: https://reviews.llvm.org/D39848
llvm-svn: 320353
Simply checking for register class equality will break once additional
register classes are added (as is done for the RVC instruction set extension).
llvm-svn: 320036
As the FPR32 and FPR64 registers have the same names, use
validateTargetOperandClass in RISCVAsmParser to coerce a parsed FPR32 to an
FPR64 when necessary. The rest of this patch is very similar to the RV32F
patch.
Differential Revision: https://reviews.llvm.org/D39895
llvm-svn: 320023
The most interesting part of this patch is probably the handling of
rounding mode arguments. Sadly, the RISC-V assembler handles floating point
rounding modes as a special "argument" when it would be more consistent to
handle them like the atomics, opcode suffixes. This patch supports parsing
this optional parameter, using InstAlias to allow parsing these floating point
instructions when no rounding mode is specified.
Differential Revision: https://reviews.llvm.org/D39893
llvm-svn: 320020
As pointed out in post-commit review of r318738, `return ReplaceNode(..)` when
both ReplaceNode and the current function return void is confusing. This patch
moves to using a more obvious early return, and moves to just using an if to
catch the one case we currently care about. A future patch that adds further
custom instruction selection can introduce a switch.
llvm-svn: 318757
The obvious approach of defining a pattern like the one below actually doesn't
work:
`def : Pat<(i32 0), (i32 X0)>;`
As was noted when Lanai made this change (https://reviews.llvm.org/rL288215),
attempting to handle the constant 0 in tablegen leads to assertions due to a
physical register being used where a virtual register is expected.
llvm-svn: 318738
Previous patches primarily ensured that codegen was possible for the standard
RISC-V instructions. However, there are a number of IR inputs that wouldn't be
appropriately lowered. This patch both adds test cases and supports lowering
for a number of these cases:
* Improved sext/zext/trunc support
* Support for setcc variants that don't map directly to RISC-V instructions
* Lowering mul, and hence support for external symbols
* addc, adde, subc, sube
* mulhs, srem, mulhu, urem, udiv, sdiv
* {srl,sra,shl}_parts
* brind
* br_jt
* bswap, ctlz, cttz, ctpop
* rotl, rotr
* BlockAddress operands
Differential Revision: https://reviews.llvm.org/D29938
llvm-svn: 318737
Although ISD::SELECT_CC is a more natural match for RISCVISD::SELECT_CC (and
ultimately the integer RISC-V conditional branch instructions), we choose to
expand ISD::SELECT_CC and lower ISD::SELECT. The appropriate compare+branch
will be created in the case where an ISD::SELECT condition value is created by
an ISD::SETCC node, which operates on XLen types. Other datatypes such as
floating point don't have conditional branch instructions, and lowering
ISD::SELECT allows more flexibility for handling these cases.
Differential Revision: https://reviews.llvm.org/D29937
llvm-svn: 318735
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
Note that this is just enough for simple function call examples to generate
working code. Support for varargs etc follows in future patches.
Differential Revision: https://reviews.llvm.org/D29936
llvm-svn: 317691
A good portion of this patch is the extra functions that needed to be
implemented to support the test case. e.g. storeRegToStackSlot,
loadRegFromStackSlot, eliminateFrameIndex.
Setting ISD::BR_CC to Expand may appear non-obvious on an architecture with
branch+cmp instructions. However, I found it much easier to deal with matching
the expanded form.
I had to change simm13_lsb0 and simm21_lsb0 to inherit from the
Operand<OtherVT> class rather than Operand<i32> in order to keep tablegen
happy. This isn't a big deal, but it does seem a shame to lose the uniformity
across immediate types when there's not an obvious benefit (I'm hoping a
tablegen expert will educate me on what I'm missing here!).
Differential Revision: https://reviews.llvm.org/D29935
llvm-svn: 317690
This required the implementation of RISCVTargetInstrInfo::copyPhysReg. Support
for lowering global addresses follow in the next patch.
Differential Revision: https://reviews.llvm.org/D29934
llvm-svn: 317685
rL162640 introduced CodeGenTarget::guessInstructionProperties. If a target
sets guessInstructionProperties=0 in its FooInstrInfo, tablegen will error if
it has to guess properties from patterns. Unfortunately,
guessInstructionProperties=0 can't be used with current upstream LLVM as
instructions in the TargetOpcode namespace are always included and sometimes
have inferred properties for mayLoad, mayStore, and hasSideEffects. This patch
provides the simplest possible fix to this problem, setting default values for
these fields in the TargetOpcode scope. There is no intended functional
change, as the explicitly set properties should match what was previously
inferred. A number of the instructions had hasSideEffects=1 inferred
unintentionally. This patch makes it explicit, while future patches (such as
D37097) correct the property.
Differential Revision: https://reviews.llvm.org/D37065
llvm-svn: 317674
This header includes CodeGen headers, and is not, itself, included by
any Target headers, so move it into CodeGen to match the layering of its
implementation.
llvm-svn: 317647
This header already includes a CodeGen header and is implemented in
lib/CodeGen, so move the header there to match.
This fixes a link error with modular codegeneration builds - where a
header and its implementation are circularly dependent and so need to be
in the same library, not split between two like this.
llvm-svn: 317379
This adds the minimum necessary to support codegen for simple ALU operations
on RV32. Prolog and epilog insertion, support for memory operations etc etc
follow in future patches.
Leave guessInstructionProperties=1 until https://reviews.llvm.org/D37065 is
reviewed and lands.
Differential Revision: https://reviews.llvm.org/D29933
llvm-svn: 316188
While parameterising by XLen, also take the opportunity to clean up the
formatting of the RISCV .td files.
This commit unifies the in-tree code with my patchset at
<https://github.com/lowrisc/riscv-llvm>.
llvm-svn: 316159
r315275 set the IsLittleEndian parameter incorrectly. This patch corrects
this, and adds a test to ensure such mistakes will be caught in the future.
llvm-svn: 316091
Reverting to investigate layering effects of MCJIT not linking
libCodeGen but using TargetMachine::getNameWithPrefix() breaking the
lldb bots.
This reverts commit r315633.
llvm-svn: 315637
Lewis Revill