diff options
| -rw-r--r-- | llvm/lib/CodeGen/MachineCopyPropagation.cpp | 24 | ||||
| -rw-r--r-- | llvm/test/CodeGen/AMDGPU/dead_copy.mir | 27 |
2 files changed, 40 insertions, 11 deletions
diff --git a/llvm/lib/CodeGen/MachineCopyPropagation.cpp b/llvm/lib/CodeGen/MachineCopyPropagation.cpp index 4655b5ba704..030db4366e9 100644 --- a/llvm/lib/CodeGen/MachineCopyPropagation.cpp +++ b/llvm/lib/CodeGen/MachineCopyPropagation.cpp @@ -275,18 +275,20 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) { ClobberRegister(Reg); } - // Remember Def is defined by the copy. - for (MCSubRegIterator SR(Def, TRI, /*IncludeSelf=*/true); SR.isValid(); - ++SR) { - CopyMap[*SR] = MI; - AvailCopyMap[*SR] = MI; - } + if (!MI->getOperand(0).isDead() && !MI->getOperand(1).isUndef()) { + // Remember Def is defined by the copy. + for (MCSubRegIterator SR(Def, TRI, /*IncludeSelf=*/true); SR.isValid(); + ++SR) { + CopyMap[*SR] = MI; + AvailCopyMap[*SR] = MI; + } - // Remember source that's copied to Def. Once it's clobbered, then - // it's no longer available for copy propagation. - RegList &DestList = SrcMap[Src]; - if (!is_contained(DestList, Def)) - DestList.push_back(Def); + // Remember source that's copied to Def. Once it's clobbered, then + // it's no longer available for copy propagation. + RegList &DestList = SrcMap[Src]; + if (!is_contained(DestList, Def)) + DestList.push_back(Def); + } continue; } diff --git a/llvm/test/CodeGen/AMDGPU/dead_copy.mir b/llvm/test/CodeGen/AMDGPU/dead_copy.mir new file mode 100644 index 00000000000..76a25f2ba80 --- /dev/null +++ b/llvm/test/CodeGen/AMDGPU/dead_copy.mir @@ -0,0 +1,27 @@ +# RUN: llc -o - %s -march=amdgcn -mcpu=fiji -run-pass=machine-cp -verify-machineinstrs | FileCheck -check-prefix=GCN %s + +# GCN-LABEL: dead_copy +# GCN: bb.0 +# GCN-NOT: dead %vgpr5 = COPY undef %vgpr11, implicit %exec +# GCN: %vgpr5 = COPY %vgpr11, implicit %exec + +--- +name: dead_copy + +body: | + + bb.0: + liveins: %vgpr11, %sgpr0, %sgpr1, %vgpr6, %vgpr7, %vgpr4 + + dead %vgpr5 = COPY undef %vgpr11, implicit %exec + + %vgpr5 = COPY %vgpr11, implicit %exec + + %sgpr14 = S_ADD_U32 %sgpr0, target-flags(amdgpu-gotprel) 1136, implicit-def %scc + %sgpr15 = S_ADDC_U32 %sgpr1, target-flags(amdgpu-gotprel32-lo) 0, implicit-def dead %scc, implicit %scc + + %vgpr10 = COPY killed %sgpr14, implicit %exec + %vgpr11 = COPY killed %sgpr15, implicit %exec + + FLAT_STORE_DWORDX4 %vgpr10_vgpr11, %vgpr4_vgpr5_vgpr6_vgpr7, 0, 0, 0, implicit %exec, implicit %flat_scr +... |
