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| author | Dan Gohman <gohman@apple.com> | 2010-02-17 00:54:58 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2010-02-17 00:54:58 +0000 |
| commit | 9ee7123ab462d97a2b242280e9bf0b47883531cb (patch) | |
| tree | 3588eaffa989e094b90f3caa5a668d725949a594 | |
| parent | 378c0b35a7b9884f1de2a9762825424fbf1813ac (diff) | |
| download | external_llvm-9ee7123ab462d97a2b242280e9bf0b47883531cb.zip external_llvm-9ee7123ab462d97a2b242280e9bf0b47883531cb.tar.gz external_llvm-9ee7123ab462d97a2b242280e9bf0b47883531cb.tar.bz2 | |
Fold bswap(undef) to undef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96432 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Analysis/ConstantFolding.cpp | 6 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/bswap-fold.ll | 6 |
2 files changed, 12 insertions, 0 deletions
diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index 6bab5ec..676a846 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -1179,6 +1179,12 @@ llvm::ConstantFoldCall(Function *F, return 0; } + if (isa<UndefValue>(Operands[0])) { + if (Name.startswith("llvm.bswap")) + return Operands[0]; + return 0; + } + return 0; } diff --git a/test/Transforms/InstCombine/bswap-fold.ll b/test/Transforms/InstCombine/bswap-fold.ll index 034c70e..a6b30c0 100644 --- a/test/Transforms/InstCombine/bswap-fold.ll +++ b/test/Transforms/InstCombine/bswap-fold.ll @@ -67,3 +67,9 @@ define i16 @test8(i64 %A) { %D = tail call i16 @llvm.bswap.i16(i16 %C) nounwind ret i16 %D } + +; Misc: Fold bswap(undef) to undef. +define i64 @foo() { + %a = call i64 @llvm.bswap.i64(i64 undef) + ret i64 %a +} |