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
Alex Bradbury