diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Target/PowerPC/PPCInstrInfo.cpp | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp b/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp index 540d6932004..0a3b969c9c3 100644 --- a/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp +++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp @@ -2480,8 +2480,6 @@ bool PPCInstrInfo::convertToImmediateForm(MachineInstr &MI, Is64BitLI = Opc != PPC::RLDICL_32; NewImm = InVal.getSExtValue(); SetCR = Opc == PPC::RLDICLo; - if (SetCR && (SExtImm & NewImm) != NewImm) - return false; break; } return false; @@ -2495,7 +2493,7 @@ bool PPCInstrInfo::convertToImmediateForm(MachineInstr &MI, int64_t ME = MI.getOperand(4).getImm(); APInt InVal(32, SExtImm, true); InVal = InVal.rotl(SH); - // Set the bits ( MB + 32 ) to ( ME + 32 ). + // Set the bits ( MB + 32 ) to ( ME + 32 ). uint64_t Mask = ((1LLU << (32 - MB)) - 1) & ~((1LLU << (31 - ME)) - 1); InVal &= Mask; // Can't replace negative values with an LI as that will sign-extend @@ -2509,8 +2507,6 @@ bool PPCInstrInfo::convertToImmediateForm(MachineInstr &MI, Is64BitLI = Opc == PPC::RLWINM8 || Opc == PPC::RLWINM8o; NewImm = InVal.getSExtValue(); SetCR = Opc == PPC::RLWINMo || Opc == PPC::RLWINM8o; - if (SetCR && (SExtImm & NewImm) != NewImm) - return false; break; } return false; @@ -2536,6 +2532,33 @@ bool PPCInstrInfo::convertToImmediateForm(MachineInstr &MI, } if (ReplaceWithLI) { + // We need to be careful with CR-setting instructions we're replacing. + if (SetCR) { + // We don't know anything about uses when we're out of SSA, so only + // replace if the new immediate will be reproduced. + bool ImmChanged = (SExtImm & NewImm) != NewImm; + if (PostRA && ImmChanged) + return false; + + if (!PostRA) { + // If the defining load-immediate has no other uses, we can just replace + // the immediate with the new immediate. + if (MRI->hasOneUse(DefMI->getOperand(0).getReg())) + DefMI->getOperand(1).setImm(NewImm); + + // If we're not using the GPR result of the CR-setting instruction, we + // just need to and with zero/non-zero depending on the new immediate. + else if (MRI->use_empty(MI.getOperand(0).getReg())) { + if (NewImm) { + assert(Immediate && "Transformation converted zero to non-zero?"); + NewImm = Immediate; + } + } + else if (ImmChanged) + return false; + } + } + LLVM_DEBUG(dbgs() << "Replacing instruction:\n"); LLVM_DEBUG(MI.dump()); LLVM_DEBUG(dbgs() << "Fed by:\n"); |
