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| author | Sanjay Patel <spatel@rotateright.com> | 2018-04-27 14:22:48 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2018-04-27 14:22:48 +0000 |
| commit | d1754765662030774356b272c3c818cac6aa11dd (patch) | |
| tree | a4b29d82065a290b09fc5215e55fb810f79e2498 /clang/lib/CodeGen/CGCall.cpp | |
| parent | 9a485985cd2817d21c8a996a1d973411aab55ab9 (diff) | |
| download | bcm5719-llvm-d1754765662030774356b272c3c818cac6aa11dd.tar.gz bcm5719-llvm-d1754765662030774356b272c3c818cac6aa11dd.zip | |
[Driver, CodeGen] add options to enable/disable an FP cast optimization
As discussed in the post-commit thread for:
rL330437 ( http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20180423/545906.html )
We need a way to opt-out of a float-to-int-to-float cast optimization because too much
existing code relies on the platform-specific undefined result of those casts when the
float-to-int overflows.
The LLVM changes associated with adding this function attribute are here:
rL330947
rL330950
rL330951
Also as suggested, I changed the LLVM doc to mention the specific sanitizer flag that
catches this problem:
rL330958
Differential Revision: https://reviews.llvm.org/D46135
llvm-svn: 331041
Diffstat (limited to 'clang/lib/CodeGen/CGCall.cpp')
| -rw-r--r-- | clang/lib/CodeGen/CGCall.cpp | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp index eed9e2f5c40..da2ff14b598 100644 --- a/clang/lib/CodeGen/CGCall.cpp +++ b/clang/lib/CodeGen/CGCall.cpp @@ -1727,6 +1727,9 @@ void CodeGenModule::ConstructDefaultFnAttrList(StringRef Name, bool HasOptnone, FuncAttrs.addAttribute("no-trapping-math", llvm::toStringRef(CodeGenOpts.NoTrappingMath)); + if (CodeGenOpts.FPCastOverflowWorkaround) + FuncAttrs.addAttribute("fp-cast-overflow-workaround", "true"); + // TODO: Are these all needed? // unsafe/inf/nan/nsz are handled by instruction-level FastMathFlags. FuncAttrs.addAttribute("no-infs-fp-math", |
