Index: lib/Target/AMDGPU/GCNHazardRecognizer.cpp =================================================================== --- lib/Target/AMDGPU/GCNHazardRecognizer.cpp +++ lib/Target/AMDGPU/GCNHazardRecognizer.cpp @@ -395,9 +395,10 @@ const MCInstrDesc &Desc = MI.getDesc(); int VDataIdx = AMDGPU::getNamedOperandIdx(Opcode, AMDGPU::OpName::vdata); - int VDataRCID = -1; - if (VDataIdx != -1) - VDataRCID = Desc.OpInfo[VDataIdx].RegClass; + if (VDataIdx == -1) + return -1; + + int VDataRCID = Desc.OpInfo[VDataIdx].RegClass; if (TII->isMUBUF(MI) || TII->isMTBUF(MI)) { // For MUBUF/MTBUF instructions this hazard only exists if the Index: test/CodeGen/AMDGPU/llvm.amdgcn.buffer.wbinvl1.vol.ll =================================================================== --- test/CodeGen/AMDGPU/llvm.amdgcn.buffer.wbinvl1.vol.ll +++ test/CodeGen/AMDGPU/llvm.amdgcn.buffer.wbinvl1.vol.ll @@ -7,9 +7,11 @@ ; GCN-NEXT: ; BB#0: ; CI-NEXT: buffer_wbinvl1_vol ; encoding: [0x00,0x00,0xc0,0xe1,0x00,0x00,0x00,0x00] ; VI-NEXT: buffer_wbinvl1_vol ; encoding: [0x00,0x00,0xfc,0xe0,0x00,0x00,0x00,0x00] -; GCN-NEXT: s_endpgm +; GCN: s_endpgm define void @test_buffer_wbinvl1_vol() #0 { call void @llvm.amdgcn.buffer.wbinvl1.vol() +; This used to crash in hazard recognizer + store i8 0, i8 addrspace(1)* undef, align 1 ret void }