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Differential D99136

[RISCV] RVV stack needs two emergency stack slots.
AbandonedPublic

Authored by NickHung on Mar 22 2021, 8:05 PM.

Details

Reviewers
HsiangKai
Summary

D94465, Function RISCVInstrInfo::getVLENFactoredAmount handles NumOfVReg.
If it's not the power of two, MUL instruction needs two virtual registers (SizeOfVector and VN).
So, two emergency stack slots may be needed for the RegScavenger.

Diff Detail

Unit TestsFailed

TimeTest
70 msx64 debian > LLVM.CodeGen/RISCV::large-stack.ll
40 msx64 debian > LLVM.CodeGen/RISCV::out-of-reach-emergency-slot.mir
30 msx64 debian > LLVM.CodeGen/RISCV::split-sp-adjust.ll
130 msx64 debian > LLVM.CodeGen/RISCV::vararg.ll
40 msx64 debian > LLVM.CodeGen/RISCV/rvv::access-fixed-objects-by-rvv.ll
View Full Test Results (14 Failed)

Revision Contents

PathSize
llvm/
lib/
Target/
RISCV/
3 lines

Diff 332503

llvm/lib/Target/RISCV/RISCVFrameLowering.cpp

Show First 20 Lines • Show All 91 Lines • ▼ Show 20 Lines
// representable an 11-bit signed field rather than 12-bits. // representable an 11-bit signed field rather than 12-bits.
// FIXME: It may be possible to craft a function with a small stack that // FIXME: It may be possible to craft a function with a small stack that
// still needs an emergency spill slot for branch relaxation. This case // still needs an emergency spill slot for branch relaxation. This case
// would currently be missed. // would currently be missed.
if (!isInt<11>(MFI.estimateStackSize(MF)) || RVVStackSize != 0) { if (!isInt<11>(MFI.estimateStackSize(MF)) || RVVStackSize != 0) {
int RegScavFI = MFI.CreateStackObject(RegInfo->getSpillSize(*RC), int RegScavFI = MFI.CreateStackObject(RegInfo->getSpillSize(*RC),
RegInfo->getSpillAlign(*RC), false); RegInfo->getSpillAlign(*RC), false);
RS->addScavengingFrameIndex(RegScavFI); RS->addScavengingFrameIndex(RegScavFI);
int RegScavFI1 = MFI.CreateStackObject(RegInfo->getSpillSize(*RC),
RegInfo->getSpillAlign(*RC), false);
Lint: Pre-merge checks
Inline Actions

clang-format: please reformat the code

-                                          RegInfo->getSpillAlign(*RC), false);
+                                           RegInfo->getSpillAlign(*RC), false);
Lint: Pre-merge checks: clang-format: please reformat the code ``` - RegInfo…
RS->addScavengingFrameIndex(RegScavFI1);
} }
} }
void RISCVFrameLowering::processFunctionBeforeFrameIndicesReplaced( void RISCVFrameLowering::processFunctionBeforeFrameIndicesReplaced(
MachineFunction &MF, RegScavenger *RS) const { MachineFunction &MF, RegScavenger *RS) const {
auto *RVFI = MF.getInfo<RISCVMachineFunctionInfo>(); auto *RVFI = MF.getInfo<RISCVMachineFunctionInfo>();
const MachineFrameInfo &MFI = MF.getFrameInfo(); const MachineFrameInfo &MFI = MF.getFrameInfo();
if (MFI.getCalleeSavedInfo().empty() || RVFI->useSaveRestoreLibCalls(MF)) { if (MFI.getCalleeSavedInfo().empty() || RVFI->useSaveRestoreLibCalls(MF)) {
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