Summary:
LLVM Allows Targets to provide information that guides optimisations
made to LLVM IR. This is done with callbacks on a TargetTransformInfo object.
This patch adds a TargetTransformInfo class for RISC-V. This will allow us to
implement RISC-V specific callbacks as they become necessary.
This commit also adds the getIntImmCost callbacks, and tests them with a simple
constant hoisting test. Our immediate costs are on the conservative side, for
the moment, but we prevent hoisting in most circumstances anyway.
Previous review was on D63007
Reviewers: asb, luismarques
Reviewed By: asb
Subscribers: ributzka, MaskRay, llvm-commits, Jim, benna, psnobl, jocewei, PkmX, rkruppe, the_o, brucehoult, MartinMosbeck, rogfer01, edward-jones, zzheng, jrtc27, shiva0217, kito-cheng, niosHD, sabuasal, apazos, simoncook, johnrusso, rbar, hiraditya, mgorny
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63433
llvm-svn: 364046
This patch adds lowering for global TLS addresses for the TLS models of
InitialExec, GlobalDynamic, LocalExec and LocalDynamic.
LocalExec support required using a 4-operand add instruction, which uses
the fourth operand to express a relocation on the symbol. The necessary
fixup is emitted when the instruction is emitted.
Differential Revision: https://reviews.llvm.org/D55305
llvm-svn: 363771
r363757 renamed ExpandISelPseudo to FinalizeISel, so the RUN line in
select-optimize-multiple.mir needed updating to refer to finalize-isel.
llvm-svn: 363762
Summary:
DAGCombine will normally turn a `(shl (add x, c1), c2)` into `(add (shl x, c2), c1 << c2)`, where `c1` and `c2` are constants. This can be prevented by a callback in TargetLowering.
On RISC-V, materialising the constant `c1 << c2` can be more expensive than materialising `c1`, because materialising the former may take more instructions, and may use a register, where materialising the latter would not.
This patch implements the hook in RISCVTargetLowering to prevent this transform, in the cases where:
- `c1` fits into the immediate field in an `addi` instruction.
- `c1` takes fewer instructions to materialise than `c1 << c2`.
In future, DAGCombine could do the check to see whether `c1` fits into an add immediate, which might simplify more targets hooks than just RISC-V.
Reviewers: asb, luismarques, efriedma
Reviewed By: asb
Subscribers: xbolva00, lebedev.ri, craig.topper, lewis-revill, Jim, hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62857
llvm-svn: 363736
This patch adds support for generating calls through the procedure
linkage table where required for a given ExternalSymbol or GlobalAddress
callee.
Differential Revision: https://reviews.llvm.org/D55304
llvm-svn: 363686
Some GEPs were not being split, presumably because that split would just be
undone by the DAGCombiner. Not performing those splits can prevent important
optimizations, such as preventing the element indices / member offsets from
being (partially) folded into load/store instruction immediates. This patch:
- Makes the splits also occur in the cases where the base address and the GEP
are in the same BB.
- Ensures that the DAGCombiner doesn't reassociate them back again.
Differential Revision: https://reviews.llvm.org/D60294
llvm-svn: 363544
In order to generate correct debug frame information, it needs to
generate CFI information in prologue and epilog.
Differential Revision: https://reviews.llvm.org/D61773
llvm-svn: 363120
This patch allows lowering of PIC addresses by using PC-relative
addressing for DSO-local symbols and accessing the address through the
global offset table for non-DSO-local symbols.
Differential Revision: https://reviews.llvm.org/D55303
llvm-svn: 363058
This validates and lowers arguments to inline asm nodes which have the
constraints I, J & K, with the following semantics (equivalent to GCC):
I: Any 12-bit signed immediate.
J: Immediate integer zero only.
K: Any 5-bit unsigned immediate.
Differential Revision: https://reviews.llvm.org/D54093
llvm-svn: 363054
Summary:
This allows some integer bitwise operations to instead be performed by
hardware fp instructions. This is correct because the RISC-V spec
requires the F and D extensions to use the IEEE-754 standard
representation, and fp register loads and stores to be bit-preserving.
This is tested against the soft-float ABI, but with hardware float
extensions enabled, so that the tests also ensure the optimisation also
fires in this case.
Reviewers: asb, luismarques
Reviewed By: asb
Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62900
llvm-svn: 362790
The 3-field form was introduced by D3499 in 2014 and the legacy 2-field
form was planned to be removed in LLVM 4.0
For the textual format, this patch migrates the existing 2-field form to
use the 3-field form and deletes the compatibility code.
test/Verifier/global-ctors-2.ll checks we have a friendly error message.
For bitcode, lib/IR/AutoUpgrade UpgradeGlobalVariables will upgrade the
2-field form (add i8* null as the third field).
Reviewed By: rnk, dexonsmith
Differential Revision: https://reviews.llvm.org/D61547
llvm-svn: 360742
This patch allows for expansion of ADDCARRY and SUBCARRY when the target does not support it.
Differential Revision: https://reviews.llvm.org/D61411
llvm-svn: 360303
When not optimizing for minimum size (-Oz) we custom lower wide shifts
(SHL_PARTS, SRA_PARTS, SRL_PARTS) instead of expanding to a libcall.
Differential Revision: https://reviews.llvm.org/D59477
llvm-svn: 358498
Because of gp = sdata_start_address + 0x800, gp with signed twelve-bit offset
could covert most of the small data section. Linker relaxation could transfer
the multiple data accessing instructions to a gp base with signed twelve-bit
offset instruction.
Differential Revision: https://reviews.llvm.org/D57493
llvm-svn: 358150
Recent change rL357393 uses MachineInstrBuilder::addDisp to add a based on a
BlockAddress but this case was not implemented.
This patch adds the missing case and a test for RISC-V that exercises the new
case.
Differential Revision: https://reviews.llvm.org/D60136
llvm-svn: 357752
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
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
vararg.ll previously missed RV64 tests. This patch also prepares for using
vararg.ll to test handling of varargs for the ilp32f/ilp32d/lp64f/lp64d hard
float ABIs. In these ABIs, varargs are passed as in either the ilp32 or lp64
ABI. Due to some slight codegen differences, different check lines are needed
for when RV32D is enabled.
llvm-svn: 357350
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
This minimises differences in output when compiling with hardware floating
point support, which will be done in a future patch (to demonstrate the same
vararg calling convention is used).
llvm-svn: 357339
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
rL356068 caused some minor re-orderings. Regenerate legalize-fneg.ll to
reflect this, and remove the NOLIB check lines (they're redundant given that
the RV32I and RV64I check lines generated by update_llc_test_checks.py already
demonstrate there is no libcall).
llvm-svn: 356074
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
Note that s0 need not be marked reserved if the frame pointer isn't used. For
the ILP32 and LP64 soft float ABIS that are currently support, all FPRs are
always considered temporaries.
llvm-svn: 356061
These are closely modeled on similar tests for the ilp32 ABI. Like those
tests, we group together tests that should be common cross lp64, lp64+lp64f,
and lp64+lp64f+lp64d ABIs.
llvm-svn: 355899
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
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
Re-organise calling convention tests to prepare for ilp32f and ilp32d hard
float ABI tests. It's also clear that we need to introduce similar tests for
lp64.
llvm-svn: 354323
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
For targets where i32 is not a legal type (e.g. 64-bit RISC-V),
LegalizeIntegerTypes must promote the integer operand of ISD::FPOWI. As this
is a signed value, this should be sign-extended.
This patch enables all tests in test/CodeGen/RISCVfloat-intrinsics.ll for
RV64, as prior to this patch that file couldn't be compiled for RV64 due to an
assertion when performing codegen for fpowi.
Differential Revision: https://reviews.llvm.org/D54574
llvm-svn: 352832
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
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
(fcopysign a, (fneg b)) will be expanded to bitwise operations by
DAGTypeLegalizer::SoftenFloatRes_FCOPYSIGN if the floating point type isn't
legal. Arguably it might be worth doing a combine even if it is legal.
llvm-svn: 352240
The intrinsic names erroneously used the .f32 variant. As the return and
argument types were still double the intrinsics calls worked properly.
llvm-svn: 352211
Sam Elliott