diff options
Diffstat (limited to 'lib/Target/ARM/ARMLoadStoreOptimizer.cpp')
-rw-r--r-- | lib/Target/ARM/ARMLoadStoreOptimizer.cpp | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/lib/Target/ARM/ARMLoadStoreOptimizer.cpp b/lib/Target/ARM/ARMLoadStoreOptimizer.cpp index b78b95b22e..19f1e3ba12 100644 --- a/lib/Target/ARM/ARMLoadStoreOptimizer.cpp +++ b/lib/Target/ARM/ARMLoadStoreOptimizer.cpp @@ -350,7 +350,8 @@ ARMLoadStoreOpt::MergeLDR_STR(MachineBasicBlock &MBB, unsigned SIndex, : ARMRegisterInfo::getRegisterNumbering(Reg); // AM4 - register numbers in ascending order. // AM5 - consecutive register numbers in ascending order. - if (NewOffset == Offset + (int)Size && + if (Reg != ARM::SP && + NewOffset == Offset + (int)Size && ((isAM4 && RegNum > PRegNum) || RegNum == PRegNum+1)) { Offset += Size; PRegNum = RegNum; @@ -747,11 +748,24 @@ 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; + + // Likewise don't mess with references to undefined addresses. + if (MI->getNumOperands() > 1 && MI->getOperand(1).isReg() && + MI->getOperand(1).isUndef()) + return false; + int Opcode = MI->getOpcode(); switch (Opcode) { default: break; |