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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-10-16 22:51:58 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-10-16 22:51:58 +0000 |
| commit | 320db3f8052c9f506d9ea043ba5da534df40aa08 (patch) | |
| tree | 8940e7352ef9f815644b8a4e4021f0d98be78ee0 /test | |
| parent | cdcdfd2cab67366b1debbe36bf46c29f7fecda67 (diff) | |
Avoid rematerializing a redef immediately after the old def.
PR14098 contains an example where we would rematerialize a MOV8ri
immediately after the original instruction:
%vreg7:sub_8bit<def> = MOV8ri 9; GR32_ABCD:%vreg7
%vreg22:sub_8bit<def> = MOV8ri 9; GR32_ABCD:%vreg7
Besides being pointless, it is also wrong since the original instruction
only redefines part of the register, and the value read by the new
instruction is wrong.
The problem was the LiveRangeEdit::allUsesAvailableAt() didn't
special-case OrigIdx == UseIdx and found the wrong SSA value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166068 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/CodeGen/X86/pr14098.ll | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/test/CodeGen/X86/pr14098.ll b/test/CodeGen/X86/pr14098.ll new file mode 100644 index 00000000000..6ce2449ab6a --- /dev/null +++ b/test/CodeGen/X86/pr14098.ll @@ -0,0 +1,23 @@ +; RUN: llc -mtriple i386-unknown-linux-gnu -relocation-model=pic -verify-machineinstrs < %s +; We used to crash on this. + +declare void @foo() +declare void @foo3(i1 %x) +define void @bar(i1 %a1, i16 %a2) nounwind align 2 { +bb0: + %a3 = trunc i16 %a2 to i8 + %a4 = lshr i16 %a2, 8 + %a5 = trunc i16 %a4 to i8 + br i1 %a1, label %bb1, label %bb2 +bb1: + br label %bb2 +bb2: + %a6 = phi i8 [ 3, %bb0 ], [ %a5, %bb1 ] + %a7 = phi i8 [ 9, %bb0 ], [ %a3, %bb1 ] + %a8 = icmp eq i8 %a6, 1 + call void @foo() + %a9 = icmp eq i8 %a7, 0 + call void @foo3(i1 %a9) + call void @foo3(i1 %a8) + ret void +} |