diff options
| author | Manman Ren <mren@apple.com> | 2012-11-27 18:58:41 +0000 |
|---|---|---|
| committer | Manman Ren <mren@apple.com> | 2012-11-27 18:58:41 +0000 |
| commit | 39834da697e5a6d0198a6a802133ce351c871904 (patch) | |
| tree | 7d65925640c6c2c94aa2d63f05f9ddf07e77c305 | |
| parent | a241b58f8d5d71eebfb2cb9be3689fe72b454474 (diff) | |
CSE: allow PerformTrivialCoalescing to check copies across basic block
boundaries.
Given the following case:
BB0
%vreg1<def> = SUBrr %vreg0, %vreg7
%vreg2<def> = COPY %vreg7
BB1
%vreg10<def> = SUBrr %vreg0, %vreg2
We should be able to CSE between SUBrr in BB0 and SUBrr in BB1.
rdar://12462006
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168717 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/CodeGen/MachineCSE.cpp | 2 | ||||
| -rw-r--r-- | test/CodeGen/ARM/machine-cse-cmp.ll | 32 |
2 files changed, 32 insertions, 2 deletions
diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp index dbc41defeb..56cea4e599 100644 --- a/lib/CodeGen/MachineCSE.cpp +++ b/lib/CodeGen/MachineCSE.cpp @@ -126,8 +126,6 @@ bool MachineCSE::PerformTrivialCoalescing(MachineInstr *MI, // deleted. continue; MachineInstr *DefMI = MRI->getVRegDef(Reg); - if (DefMI->getParent() != MBB) - continue; if (!DefMI->isCopy()) continue; unsigned SrcReg = DefMI->getOperand(1).getReg(); diff --git a/test/CodeGen/ARM/machine-cse-cmp.ll b/test/CodeGen/ARM/machine-cse-cmp.ll index 3ac7d77d6f..03abd762a2 100644 --- a/test/CodeGen/ARM/machine-cse-cmp.ll +++ b/test/CodeGen/ARM/machine-cse-cmp.ll @@ -45,3 +45,35 @@ for.cond1.preheader: ; preds = %entry } declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) nounwind + +; rdar://12462006 +define i8* @f3(i8* %base, i32* nocapture %offset, i32 %size) nounwind { +entry: +; CHECK: f3: +; CHECK-NOT: sub +; CHECK: cmp +; CHECK: blt +%0 = load i32* %offset, align 4 +%cmp = icmp slt i32 %0, %size +%s = sub nsw i32 %0, %size +%size2 = sub nsw i32 %size, 0 +br i1 %cmp, label %return, label %if.end + +if.end: +; We are checking cse between %sub here and %s in entry block. +%sub = sub nsw i32 %0, %size2 +%s2 = sub nsw i32 %s, %size +%s3 = sub nsw i32 %sub, %s2 +; CHECK: sub [[R1:r[0-9]+]], [[R2:r[0-9]+]], r2 +; CHECK: sub [[R3:r[0-9]+]], [[R1]], r2 +; CHECK: sub [[R4:r[0-9]+]], [[R1]], [[R3]] +; CHECK-NOT: sub +; CHECK: str +store i32 %s3, i32* %offset, align 4 +%add.ptr = getelementptr inbounds i8* %base, i32 %sub +br label %return + +return: +%retval.0 = phi i8* [ %add.ptr, %if.end ], [ null, %entry ] +ret i8* %retval.0 +} |