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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2012-10-19 20:43:44 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2012-10-19 20:43:44 +0000 |
| commit | 0aae4bd0fc9133ba3b4e59d6cdb05b878fc8f436 (patch) | |
| tree | ad9ce31279574e965cf4603e2fa6385505f6f892 | |
| parent | 28ce1cc183582e4061f1e5ba4fb443d99a4915ae (diff) | |
SimplifyLibcalls: The return value of ffsll is always i32, even when the input is zero.
Fixes PR13028.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166313 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 4 | ||||
| -rw-r--r-- | test/Transforms/SimplifyLibCalls/FFS.ll | 15 |
2 files changed, 14 insertions, 5 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index 90efa8ae0e..c82a00fc2c 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -772,8 +772,8 @@ struct FFSOpt : public LibCallOptimization { // Constant fold. if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) { - if (CI->getValue() == 0) // ffs(0) -> 0. - return Constant::getNullValue(CI->getType()); + if (CI->isZero()) // ffs(0) -> 0. + return B.getInt32(0); // ffs(c) -> cttz(c)+1 return B.getInt32(CI->getValue().countTrailingZeros() + 1); } diff --git a/test/Transforms/SimplifyLibCalls/FFS.ll b/test/Transforms/SimplifyLibCalls/FFS.ll index e38d78349d..6aecbeacd7 100644 --- a/test/Transforms/SimplifyLibCalls/FFS.ll +++ b/test/Transforms/SimplifyLibCalls/FFS.ll @@ -1,6 +1,7 @@ -; Test that the ToAsciiOptimizer works correctly -; RUN: opt < %s -simplify-libcalls -S | \ -; RUN: not grep "call.*@ffs" +; Test that FFSOpt works correctly +; RUN: opt < %s -simplify-libcalls -S | FileCheck %s + +; CHECK-NOT: call{{.*}}@ffs @non_const = external global i32 ; <i32*> [#uses=1] @@ -34,3 +35,11 @@ define i32 @a(i64) nounwind { %2 = call i32 @ffsll(i64 %0) ; <i32> [#uses=1] ret i32 %2 } + +; PR13028 +define i32 @b() nounwind { + %ffs = call i32 @ffsll(i64 0) + ret i32 %ffs +; CHECK: @b +; CHECK-NEXT: ret i32 0 +} |