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| author | Dale Johannesen <dalej@apple.com> | 2011-01-10 21:53:07 +0000 |
|---|---|---|
| committer | Dale Johannesen <dalej@apple.com> | 2011-01-10 21:53:07 +0000 |
| commit | 97fd9a58de3c99a74b0890a908430fa3ab894bed (patch) | |
| tree | 9fa01c8038a9edfc81cb63ce9f6319d4107c95a5 /test/CodeGen/X86/2011-01-10-DagCombineHang.ll | |
| parent | 4a6fb94c4088fbfc42042007f6c6c8eef7fc4b27 (diff) | |
| download | external_llvm-97fd9a58de3c99a74b0890a908430fa3ab894bed.zip external_llvm-97fd9a58de3c99a74b0890a908430fa3ab894bed.tar.gz external_llvm-97fd9a58de3c99a74b0890a908430fa3ab894bed.tar.bz2 | |
Fix PR 8916 (qv for analysis), at least the immediate problem.
There's an inherent tension in DAGCombine between assuming
that things will be put in canonical form, and the Depth
mechanism that disables transformations when recursion gets
too deep. It would not surprise me if there's a lot of little
bugs like this one waiting to be discovered. The mechanism
seems fragile and I'd suggest looking at it from a design viewpoint.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123191 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/X86/2011-01-10-DagCombineHang.ll')
| -rw-r--r-- | test/CodeGen/X86/2011-01-10-DagCombineHang.ll | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/test/CodeGen/X86/2011-01-10-DagCombineHang.ll b/test/CodeGen/X86/2011-01-10-DagCombineHang.ll new file mode 100644 index 0000000..bf438b8 --- /dev/null +++ b/test/CodeGen/X86/2011-01-10-DagCombineHang.ll @@ -0,0 +1,15 @@ +; RUN: llc < %s -mtriple=x86_64-apple-darwin10 +; This formerly got DagCombine into a loop, PR 8916. + +define i32 @foo(i64 %x, i64 %y, i64 %z, i32 %a, i32 %b) { +entry: + %"alloca point" = bitcast i32 0 to i32 ; <i32> [#uses=0] + %t1 = shl i64 %x, 15 + %t2 = and i64 %t1, 4294934528 + %t3 = or i64 %t2, %y + %t4 = xor i64 %z, %t3 + %t5 = trunc i64 %t4 to i32 + %t6 = add i32 %a, %t5 + %t7 = add i32 %t6, %b + ret i32 %t7 +} |