diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Target/AMDGPU/SIFoldOperands.cpp | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp index ccbf7c80f2a..6230d1e28b7 100644 --- a/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp +++ b/llvm/lib/Target/AMDGPU/SIFoldOperands.cpp @@ -338,6 +338,17 @@ bool SIFoldOperands::runOnMachineFunction(MachineFunction &MF) { !TargetRegisterInfo::isVirtualRegister(OpToFold.getReg())) continue; + // Prevent folding operands backwards in the function. For example, + // the COPY opcode must not be replaced by 1 in this example: + // + // %vreg3<def> = COPY %VGPR0; VGPR_32:%vreg3 + // ... + // %VGPR0<def> = V_MOV_B32_e32 1, %EXEC<imp-use> + MachineOperand &Dst = MI.getOperand(0); + if (Dst.isReg() && + !TargetRegisterInfo::isVirtualRegister(Dst.getReg())) + continue; + // We need mutate the operands of new mov instructions to add implicit // uses of EXEC, but adding them invalidates the use_iterator, so defer // this. |
