Index: llvm/trunk/lib/Target/AMDGPU/SIInstrInfo.cpp =================================================================== --- llvm/trunk/lib/Target/AMDGPU/SIInstrInfo.cpp +++ llvm/trunk/lib/Target/AMDGPU/SIInstrInfo.cpp @@ -770,7 +770,7 @@ if (ST.hasScalarStores()) { // m0 is used for offset to scalar stores if used to spill. - Spill.addReg(AMDGPU::M0, RegState::ImplicitDefine); + Spill.addReg(AMDGPU::M0, RegState::ImplicitDefine | RegState::Dead); } return; @@ -871,7 +871,7 @@ if (ST.hasScalarStores()) { // m0 is used for offset to scalar stores if used to spill. - Spill.addReg(AMDGPU::M0, RegState::ImplicitDefine); + Spill.addReg(AMDGPU::M0, RegState::ImplicitDefine | RegState::Dead); } return; Index: llvm/trunk/test/CodeGen/AMDGPU/spill-to-smem-m0.ll =================================================================== --- llvm/trunk/test/CodeGen/AMDGPU/spill-to-smem-m0.ll +++ llvm/trunk/test/CodeGen/AMDGPU/spill-to-smem-m0.ll @@ -0,0 +1,22 @@ +; RUN: llc -O0 -march=amdgcn -mcpu=fiji -amdgpu-spill-sgpr-to-smem=1 -verify-machineinstrs -stop-before=prologepilog < %s + +; Spill to SMEM clobbers M0. Check that the implicit-def dead operand is present +; in the pseudo instructions. + +; CHECK-LABEL: {{^}}spill_sgpr: +; CHECK: SI_SPILL_S32_SAVE {{.*}}, implicit-def dead %m0 +; CHECK: SI_SPILL_S32_RESTORE {{.*}}, implicit-def dead %m0 +define amdgpu_kernel void @spill_sgpr(i32 addrspace(1)* %out, i32 %in) #0 { + %sgpr = call i32 asm sideeffect "; def $0", "=s" () #0 + %cmp = icmp eq i32 %in, 0 + br i1 %cmp, label %bb0, label %ret + +bb0: + call void asm sideeffect "; use $0", "s"(i32 %sgpr) #0 + br label %ret + +ret: + ret void +} + +attributes #0 = { nounwind }