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| author | Shuxin Yang <shuxin.llvm@gmail.com> | 2013-01-09 00:13:41 +0000 |
|---|---|---|
| committer | Shuxin Yang <shuxin.llvm@gmail.com> | 2013-01-09 00:13:41 +0000 |
| commit | 935e35d2b9f889566207b76a7026b63a1619742c (patch) | |
| tree | cc26ce74146b052bea87a9ca28314767d6cef72b /lib/IR/Constants.cpp | |
| parent | b6714227eda5d499f7667fc865f931126a8dc488 (diff) | |
| download | llvm-935e35d2b9f889566207b76a7026b63a1619742c.tar.gz llvm-935e35d2b9f889566207b76a7026b63a1619742c.tar.bz2 llvm-935e35d2b9f889566207b76a7026b63a1619742c.tar.xz | |
Consider expression "0.0 - X" as the negation of X if
- this expression is explicitly marked no-signed-zero, or
- no-signed-zero of this expression can be derived from some context.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171922 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/IR/Constants.cpp')
| -rw-r--r-- | lib/IR/Constants.cpp | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/IR/Constants.cpp b/lib/IR/Constants.cpp index 4b58599955..812692f3fa 100644 --- a/lib/IR/Constants.cpp +++ b/lib/IR/Constants.cpp @@ -51,6 +51,15 @@ bool Constant::isNegativeZeroValue() const { return isNullValue(); } +bool Constant::isZeroValue() const { + // Floating point values have an explicit -0.0 value. + if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this)) + return CFP->isZero(); + + // Otherwise, just use +0.0. + return isNullValue(); +} + bool Constant::isNullValue() const { // 0 is null. if (const ConstantInt *CI = dyn_cast<ConstantInt>(this)) |