Stay away from str <undef> in ARMLoadStoreOpt. This pass does not understand

<undef> operands, and can cause scavenger failures when it translates
<kill,undef> to <kill>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97046 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2010-02-24 18:57:08 +00:00
parent 39b03163a7
commit 9e6396d05e

View File

@ -748,11 +748,19 @@ static bool isMemoryOp(const MachineInstr *MI) {
if (MMO->isVolatile())
return false;
// Unaligned ldr/str is emulated by some kernels, but unaligned ldm/stm is not.
// Unaligned ldr/str is emulated by some kernels, but unaligned ldm/stm is
// not.
if (MMO->getAlignment() < 4)
return false;
}
// str <undef> could probably be eliminated entirely, but for now we just want
// to avoid making a mess of it.
// FIXME: Use str <undef> as a wildcard to enable better stm folding.
if (MI->getNumOperands() > 0 && MI->getOperand(0).isReg() &&
MI->getOperand(0).isUndef())
return false;
int Opcode = MI->getOpcode();
switch (Opcode) {
default: break;