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| author | Michael Kuperstein <mkuper@google.com> | 2016-11-23 18:33:49 +0000 |
|---|---|---|
| committer | Michael Kuperstein <mkuper@google.com> | 2016-11-23 18:33:49 +0000 |
| commit | 47eb85a0033fd21764fe100e736c3ec54d4f741f (patch) | |
| tree | 87b3a0867fc7cfd6773183ffa1082de972f1bbc8 /llvm/lib/CodeGen/InlineSpiller.cpp | |
| parent | 3c3fe5d885b8772634a7571907400580873ab611 (diff) | |
| download | llvm-47eb85a0033fd21764fe100e736c3ec54d4f741f.zip llvm-47eb85a0033fd21764fe100e736c3ec54d4f741f.tar.gz llvm-47eb85a0033fd21764fe100e736c3ec54d4f741f.tar.bz2 | |
[X86] Allow folding of stack reloads when loading a subreg of the spilled reg
We did not support subregs in InlineSpiller:foldMemoryOperand() because targets
may not deal with them correctly.
This adds a target hook to let the spiller know that a target can handle
subregs, and actually enables it for x86 for the case of stack slot reloads.
This fixes PR30832.
Differential Revision: https://reviews.llvm.org/D26521
llvm-svn: 287792
Diffstat (limited to 'llvm/lib/CodeGen/InlineSpiller.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/InlineSpiller.cpp | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/llvm/lib/CodeGen/InlineSpiller.cpp b/llvm/lib/CodeGen/InlineSpiller.cpp index 3ccc18d..3e5ae5f 100644 --- a/llvm/lib/CodeGen/InlineSpiller.cpp +++ b/llvm/lib/CodeGen/InlineSpiller.cpp @@ -739,9 +739,12 @@ foldMemoryOperand(ArrayRef<std::pair<MachineInstr*, unsigned> > Ops, bool WasCopy = MI->isCopy(); unsigned ImpReg = 0; - bool SpillSubRegs = (MI->getOpcode() == TargetOpcode::STATEPOINT || - MI->getOpcode() == TargetOpcode::PATCHPOINT || - MI->getOpcode() == TargetOpcode::STACKMAP); + // Spill subregs if the target allows it. + // We always want to spill subregs for stackmap/patchpoint pseudos. + bool SpillSubRegs = TII.isSubregFoldable() || + MI->getOpcode() == TargetOpcode::STATEPOINT || + MI->getOpcode() == TargetOpcode::PATCHPOINT || + MI->getOpcode() == TargetOpcode::STACKMAP; // TargetInstrInfo::foldMemoryOperand only expects explicit, non-tied // operands. @@ -754,7 +757,7 @@ foldMemoryOperand(ArrayRef<std::pair<MachineInstr*, unsigned> > Ops, ImpReg = MO.getReg(); continue; } - // FIXME: Teach targets to deal with subregs. + if (!SpillSubRegs && MO.getSubReg()) return false; // We cannot fold a load instruction into a def. |