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| author | James Greenhalgh <james.greenhalgh@arm.com> | 2016-12-20 16:17:27 +0000 |
|---|---|---|
| committer | James Greenhalgh <jgreenhalgh@gcc.gnu.org> | 2016-12-20 16:17:27 +0000 |
| commit | 314e1b47dceafda7a52650915648703236bc4f23 (patch) | |
| tree | b7b1211e081da6609886060d597693664c100be5 /gcc/doc | |
| parent | aa90531ea4cfe2ceb9150943f601b67907b27811 (diff) | |
| download | gcc-314e1b47dceafda7a52650915648703236bc4f23.zip gcc-314e1b47dceafda7a52650915648703236bc4f23.tar.gz gcc-314e1b47dceafda7a52650915648703236bc4f23.tar.bz2 | |
[Patch] Turn -fexcess-precision=fast on when in -ffast-math
* common.opt (excess_precision): Tag as SetByCombined.
* opts.c (set_fast_math_flags): Also set
flag_excess_precision_cmdline.
(fast_math_flags_set_p): Also check flag_excess_precision_cmdline.
* doc/invoke.texi (-fexcess-precision): Drop text saying the
option has no effect under -ffast-math, make it clear that
-ffast-math will cause -fexcess-precision=fast by default even for
standards compliant modes.
(-ffast-math): Document that this sets -fexcess-precision=fast.
From-SVN: r243824
Diffstat (limited to 'gcc/doc')
| -rw-r--r-- | gcc/doc/invoke.texi | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index b729964..5c92fe6 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -9109,12 +9109,12 @@ both casts and assignments cause values to be rounded to their semantic types (whereas @option{-ffloat-store} only affects assignments). This option is enabled by default for C if a strict conformance option such as @option{-std=c99} is used. +@option{-ffast-math} enables @option{-fexcess-precision=fast} by default +regardless of whether a strict conformance option is used. @opindex mfpmath @option{-fexcess-precision=standard} is not implemented for languages -other than C, and has no effect if -@option{-funsafe-math-optimizations} or @option{-ffast-math} is -specified. On the x86, it also has no effect if @option{-mfpmath=sse} +other than C. On the x86, it has no effect if @option{-mfpmath=sse} or @option{-mfpmath=sse+387} is specified; in the former case, IEEE semantics apply without excess precision, and in the latter, rounding is unpredictable. @@ -9123,7 +9123,8 @@ is unpredictable. @opindex ffast-math Sets the options @option{-fno-math-errno}, @option{-funsafe-math-optimizations}, @option{-ffinite-math-only}, @option{-fno-rounding-math}, -@option{-fno-signaling-nans} and @option{-fcx-limited-range}. +@option{-fno-signaling-nans}, @option{-fcx-limited-range} and +@option{-fexcess-precision=fast}. This option causes the preprocessor macro @code{__FAST_MATH__} to be defined. |