diff --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp index 1779e746bad36..781a8dd8f68e8 100644 --- a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp +++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp @@ -8071,7 +8071,7 @@ bool llvm::execMayBeModifiedBeforeAnyUse(const MachineRegisterInfo &MRI, auto &UseInst = *Use.getParent(); // Don't bother searching between blocks, although it is possible this block // doesn't modify exec. - if (UseInst.getParent() != DefBB) + if (UseInst.getParent() != DefBB || UseInst.isPHI()) return true; if (++NumUse > MaxUseScan) diff --git a/llvm/test/CodeGen/AMDGPU/dpp_combine.mir b/llvm/test/CodeGen/AMDGPU/dpp_combine.mir index 1c896b44b3ac0..07259dbaa02bd 100644 --- a/llvm/test/CodeGen/AMDGPU/dpp_combine.mir +++ b/llvm/test/CodeGen/AMDGPU/dpp_combine.mir @@ -883,3 +883,58 @@ body: | %5:vgpr_32 = V_ADD_CO_U32_e32 %4.sub0, %4.sub0, implicit-def $vcc, implicit $exec %6:vgpr_32 = V_ADDC_U32_e32 %4.sub1, %4.sub1, implicit-def $vcc, implicit $vcc, implicit $exec ... + +# execMayBeModifiedBeforeAnyUse used to assert if the queried +# V_MOV_B32_dpp was the last instruction in the block. +--- +name: mov_dpp_last_block_inst +tracksRegLiveness: true +body: | + ; GCN-LABEL: name: mov_dpp_last_block_inst + ; GCN: bb.0: + ; GCN-NEXT: successors: %bb.1(0x80000000) + ; GCN-NEXT: liveins: $vgpr0, $sgpr4_sgpr5, $sgpr6_sgpr7, $sgpr8 + ; GCN-NEXT: {{ $}} + ; GCN-NEXT: [[COPY:%[0-9]+]]:sgpr_32 = COPY $sgpr8 + ; GCN-NEXT: [[DEF:%[0-9]+]]:vgpr_32 = IMPLICIT_DEF + ; GCN-NEXT: [[DEF1:%[0-9]+]]:sreg_32 = IMPLICIT_DEF + ; GCN-NEXT: [[DEF2:%[0-9]+]]:sreg_64_xexec = IMPLICIT_DEF + ; GCN-NEXT: {{ $}} + ; GCN-NEXT: bb.1: + ; GCN-NEXT: successors: %bb.2(0x80000000) + ; GCN-NEXT: {{ $}} + ; GCN-NEXT: [[PHI:%[0-9]+]]:vgpr_32 = PHI [[DEF]], %bb.0, %5, %bb.2 + ; GCN-NEXT: [[V_MOV_B32_dpp:%[0-9]+]]:vgpr_32 = V_MOV_B32_dpp [[DEF]], [[PHI]], 323, 15, 15, 0, implicit $exec + ; GCN-NEXT: {{ $}} + ; GCN-NEXT: bb.2: + ; GCN-NEXT: successors: %bb.1(0x40000000), %bb.3(0x40000000) + ; GCN-NEXT: {{ $}} + ; GCN-NEXT: [[V_CNDMASK_B32_e64_:%[0-9]+]]:vgpr_32 = V_CNDMASK_B32_e64 0, 0, 0, 1, [[DEF2]], implicit $exec + ; GCN-NEXT: V_CMP_NE_U32_e32 1, [[V_CNDMASK_B32_e64_]], implicit-def $vcc, implicit $exec + ; GCN-NEXT: S_CBRANCH_VCCNZ %bb.1, implicit $vcc + ; GCN-NEXT: S_BRANCH %bb.3 + ; GCN-NEXT: {{ $}} + ; GCN-NEXT: bb.3: + ; GCN-NEXT: S_ENDPGM 0 + bb.0: + liveins: $vgpr0, $sgpr4_sgpr5, $sgpr6_sgpr7, $sgpr8 + + %0:sgpr_32 = COPY $sgpr8 + %1:vgpr_32 = IMPLICIT_DEF + %2:sreg_32 = IMPLICIT_DEF + %3:sreg_64_xexec = IMPLICIT_DEF + + bb.1: + %4:vgpr_32 = PHI %1, %bb.0, %5, %bb.2 + %5:vgpr_32 = V_MOV_B32_dpp %1, %4, 323, 15, 15, 0, implicit $exec + + bb.2: + %6:vgpr_32 = V_CNDMASK_B32_e64 0, 0, 0, 1, %3, implicit $exec + V_CMP_NE_U32_e32 1, %6, implicit-def $vcc, implicit $exec + S_CBRANCH_VCCNZ %bb.1, implicit $vcc + S_BRANCH %bb.3 + + bb.3: + S_ENDPGM 0 + +...