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| author | Sanjay Patel <spatel@rotateright.com> | 2015-04-09 15:03:23 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2015-04-09 15:03:23 +0000 |
| commit | 359b105745cc7edf0d3c84a697de596ee331374d (patch) | |
| tree | 759cf9f38fe866fbf3ad7dea34718629a26a5f46 /clang/lib/Driver/Tools.cpp | |
| parent | f4db5462e3370b604e551ec6bb81441a254d77a4 (diff) | |
| download | llvm-359b105745cc7edf0d3c84a697de596ee331374d.zip llvm-359b105745cc7edf0d3c84a697de596ee331374d.tar.gz llvm-359b105745cc7edf0d3c84a697de596ee331374d.tar.bz2 | |
Process the -freciprocal-math optimization flag (PR20912)
The driver currently accepts but ignores the -freciprocal-math flag.
This patch passes the flag through and enables 'arcp' fast-math-flag
generation in IR.
Note that this change does not actually enable the optimization for
any target. The reassociation optimization that this flag specifies
was implemented by http://reviews.llvm.org/D6334 :
http://llvm.org/viewvc/llvm-project?view=revision&revision=222510
Because the optimization is done in the backend rather than IR,
the backend must be modified to understand instruction-level
fast-math-flags or a new function-level attribute must be created.
Also note that -freciprocal-math is independent of any target-specific
usage of reciprocal estimate hardware instructions. That requires
its own flag ('-mrecip').
https://llvm.org/bugs/show_bug.cgi?id=20912
llvm-svn: 234493
Diffstat (limited to 'clang/lib/Driver/Tools.cpp')
| -rw-r--r-- | clang/lib/Driver/Tools.cpp | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp index f0fc574..9ebf681 100644 --- a/clang/lib/Driver/Tools.cpp +++ b/clang/lib/Driver/Tools.cpp @@ -3062,6 +3062,9 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA, if (!SignedZeros) CmdArgs.push_back("-fno-signed-zeros"); + if (ReciprocalMath) + CmdArgs.push_back("-freciprocal-math"); + // Validate and pass through -fp-contract option. if (Arg *A = Args.getLastArg(options::OPT_ffast_math, FastMathAliasOption, options::OPT_fno_fast_math, |