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| author | Bill Wendling <isanbard@gmail.com> | 2009-03-04 00:18:06 +0000 |
|---|---|---|
| committer | Bill Wendling <isanbard@gmail.com> | 2009-03-04 00:18:06 +0000 |
| commit | 36ae6c182759871a4af71d9af85f970b29a669f1 (patch) | |
| tree | 76f7ebdf6942034a2aa5a3001aa850f90871970f /test/CodeGen/X86/2009-03-03-BTHang.ll | |
| parent | 127a7936dea7b86e5cad337ad4b537bc115c2588 (diff) | |
| download | llvm-36ae6c182759871a4af71d9af85f970b29a669f1.tar.gz llvm-36ae6c182759871a4af71d9af85f970b29a669f1.tar.bz2 llvm-36ae6c182759871a4af71d9af85f970b29a669f1.tar.xz | |
The DAG combiner was performing a BT combine. The BT combine had a value of -1,
so it changed it into a 31 via the TLO.ShrinkDemandedConstant() call. Then it
would go through the DAG combiner again. This time it had a value of 31, which
was turned into a -1 by TLI.SimplifyDemandedBits(). This would ping pong
forever.
Teach the TLO.ShrinkDemandedConstant() call not to lower a value if the demanded
value is an XOR of all ones.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65985 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/X86/2009-03-03-BTHang.ll')
| -rw-r--r-- | test/CodeGen/X86/2009-03-03-BTHang.ll | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/test/CodeGen/X86/2009-03-03-BTHang.ll b/test/CodeGen/X86/2009-03-03-BTHang.ll new file mode 100644 index 0000000000..0f338d8ead --- /dev/null +++ b/test/CodeGen/X86/2009-03-03-BTHang.ll @@ -0,0 +1,37 @@ +; RUN: llvm-as < %s | llc -march=x86 +; rdar://6642541 + + %struct.HandleBlock = type { [30 x i32], [990 x i8*], %struct.HandleBlockTrailer } + %struct.HandleBlockTrailer = type { %struct.HandleBlock* } + +define hidden zeroext i8 @IsHandleAllocatedFromPool(i8** %h) nounwind optsize { +entry: + %0 = ptrtoint i8** %h to i32 ; <i32> [#uses=2] + %1 = and i32 %0, -4096 ; <i32> [#uses=1] + %2 = inttoptr i32 %1 to %struct.HandleBlock* ; <%struct.HandleBlock*> [#uses=3] + %3 = getelementptr %struct.HandleBlock* %2, i32 0, i32 0, i32 0 ; <i32*> [#uses=1] + %4 = load i32* %3, align 4096 ; <i32> [#uses=1] + %5 = icmp eq i32 %4, 1751280747 ; <i1> [#uses=1] + br i1 %5, label %bb, label %bb1 + +bb: ; preds = %entry + %6 = getelementptr %struct.HandleBlock* %2, i32 0, i32 1 ; <[990 x i8*]*> [#uses=1] + %7 = ptrtoint [990 x i8*]* %6 to i32 ; <i32> [#uses=1] + %8 = sub i32 %0, %7 ; <i32> [#uses=2] + %9 = lshr i32 %8, 2 ; <i32> [#uses=1] + %10 = ashr i32 %8, 7 ; <i32> [#uses=1] + %11 = and i32 %10, 134217727 ; <i32> [#uses=1] + %12 = getelementptr %struct.HandleBlock* %2, i32 0, i32 0, i32 %11 ; <i32*> [#uses=1] + %not.i = and i32 %9, 31 ; <i32> [#uses=1] + %13 = xor i32 %not.i, 31 ; <i32> [#uses=1] + %14 = shl i32 1, %13 ; <i32> [#uses=1] + %15 = load i32* %12, align 4 ; <i32> [#uses=1] + %16 = and i32 %15, %14 ; <i32> [#uses=1] + %17 = icmp eq i32 %16, 0 ; <i1> [#uses=1] + %tmp = zext i1 %17 to i8 ; <i8> [#uses=1] + ret i8 %tmp + +bb1: ; preds = %entry + ret i8 0 +} + |