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 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
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
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
The srli test in alu8.ll was a no-op, as it shifted by 8 bits. Fix this, and
also change the immediate in alu16.ll as shifted by something other than a
poewr of 8 is more interesting.
llvm-svn: 343958
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
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
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
There is no way in the universe, that doing a full-width division in
software will be faster than doing overflowing multiplication in
software in the first place, especially given that this same full-width
multiplication needs to be done anyway.
This patch replaces the previous implementation with a direct lowering
into an overflowing multiplication algorithm based on half-width
operations.
Correctness of the algorithm was verified by exhaustively checking the
output of this algorithm for overflowing multiplication of 16 bit
integers against an obviously correct widening multiplication. Baring
any oversights introduced by porting the algorithm to DAG, confidence in
correctness of this algorithm is extremely high.
Following table shows the change in both t = runtime and s = space. The
change is expressed as a multiplier of original, so anything under 1 is
“better” and anything above 1 is worse.
+-------+-----------+-----------+-------------+-------------+
| Arch | u64*u64 t | u64*u64 s | u128*u128 t | u128*u128 s |
+-------+-----------+-----------+-------------+-------------+
| X64 | - | - | ~0.5 | ~0.64 |
| i686 | ~0.5 | ~0.6666 | ~0.05 | ~0.9 |
| armv7 | - | ~0.75 | - | ~1.4 |
+-------+-----------+-----------+-------------+-------------+
Performance numbers have been collected by running overflowing
multiplication in a loop under `perf` on two x86_64 (one Intel Haswell,
other AMD Ryzen) based machines. Size numbers have been collected by
looking at the size of function containing an overflowing multiply in
a loop.
All in all, it can be seen that both performance and size has improved
except in the case of armv7 where code size has regressed for 128-bit
multiply. u128*u128 overflowing multiply on 32-bit platforms seem to
benefit from this change a lot, taking only 5% of the time compared to
original algorithm to calculate the same thing.
The final benefit of this change is that LLVM is now capable of lowering
the overflowing unsigned multiply for integers of any bit-width as long
as the target is capable of lowering regular multiplication for the same
bit-width. Previously, 128-bit overflowing multiply was the widest
possible.
Patch by Simonas Kazlauskas!
Differential Revision: https://reviews.llvm.org/D50310
llvm-svn: 339922
When emitting the difference between two symbols, the standard behavior is
that the difference will be resolved to an absolute value if both of the
symbols are offsets from the same data fragment. This is undesirable on
architectures such as RISC-V where relaxation in the linker may cause the
computed difference to become invalid. This caused an issue when compiling to
object code, where the size of a function in the debug information was already
calculated even though it could change as a consequence of relaxation in the
subsequent linking stage.
This patch inhibits the resolution of symbol differences to absolute values
where the target's AsmBackend has declared that it does not want these to be
folded.
Differential Revision: https://reviews.llvm.org/D45773
Patch by Edward Jones.
llvm-svn: 339864
- 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
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
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
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
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
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 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
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
This test case demonstrates that common subexpression elimination takes place
between code sequences for materialising constants. In particular, it
demonstrates that redundant lui aren't generated. This would capture a
regression if applying a patch such as D41949.
llvm-svn: 330291
The objdump tests interfere with update_llc_test_checks.py and can't be
automatically update them. Put the sanitify check for compression on the
codegen codepath into a separate file, and expand it to also include tests of
integer materialisation. This would catch changes such as those triggered by
D41949.
llvm-svn: 330288
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:
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
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
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
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
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
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
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.
The MIR printer prints the IR name of a MBB only for block definitions.
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix
Differential Revision: https://reviews.llvm.org/D40422
llvm-svn: 319665
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
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
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
Alex Bradbury