diff options
| -rw-r--r-- | llvm/lib/CodeGen/MachineCopyPropagation.cpp | 4 | ||||
| -rw-r--r-- | llvm/test/CodeGen/AArch64/machine-dead-copy.mir | 32 |
2 files changed, 35 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/MachineCopyPropagation.cpp b/llvm/lib/CodeGen/MachineCopyPropagation.cpp index 4c1717e1ec3..8b6777f06db 100644 --- a/llvm/lib/CodeGen/MachineCopyPropagation.cpp +++ b/llvm/lib/CodeGen/MachineCopyPropagation.cpp @@ -399,7 +399,9 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) { MachineInstr *MI = &*I; ++I; - if (MI->isCopy()) { + // Analyze copies (which don't overlap themselves). + if (MI->isCopy() && !TRI->regsOverlap(MI->getOperand(0).getReg(), + MI->getOperand(1).getReg())) { unsigned Def = MI->getOperand(0).getReg(); unsigned Src = MI->getOperand(1).getReg(); diff --git a/llvm/test/CodeGen/AArch64/machine-dead-copy.mir b/llvm/test/CodeGen/AArch64/machine-dead-copy.mir index a3d7e7cbbf7..09548f3f608 100644 --- a/llvm/test/CodeGen/AArch64/machine-dead-copy.mir +++ b/llvm/test/CodeGen/AArch64/machine-dead-copy.mir @@ -6,6 +6,8 @@ define i32 @copyprop2(i32 %a, i32 %b) { ret i32 %a } define i32 @copyprop3(i32 %a, i32 %b) { ret i32 %a } define i32 @copyprop4(i32 %a, i32 %b) { ret i32 %a } + define i32 @copyprop5(i32 %a, i32 %b) { ret i32 %a } + define i32 @copyprop6(i32 %a, i32 %b) { ret i32 %a } declare i32 @foo(i32) ... --- @@ -65,3 +67,33 @@ body: | RET_ReallyLR implicit $w0 ... +# Don't try to erase any COPY which overlaps itself. +# CHECK-LABEL: name: copyprop5 +# CHECK: bb.0: +# CHECK: COPY killed $q26_q27_q28_q29 +# CHECK: COPY killed $q28_q29_q30_q31 +name: copyprop5 +body: | + bb.0: + liveins: $q26_q27_q28_q29 + $q28_q29_q30_q31 = COPY killed $q26_q27_q28_q29 + $q26_q27_q28_q29 = COPY killed $q28_q29_q30_q31 + BL @foo, csr_aarch64_aapcs, implicit killed $q26_q27_q28_q29 + RET_ReallyLR +... + +# Don't try to analyze any COPY which overlaps itself. +# CHECK-LABEL: name: copyprop6 +# CHECK: bb.0: +# CHECK: COPY killed $q26_q27_q28_q29 +# CHECK: $q30 = COPY $q28 +name: copyprop6 +body: | + bb.0: + liveins: $q26_q27_q28_q29 + $q28_q29_q30_q31 = COPY killed $q26_q27_q28_q29 + $q30 = COPY $q28 + BL @foo, csr_aarch64_aapcs, implicit killed $q28_q29_q30_q31 + RET_ReallyLR +... + |
