From ce2d9549f2b2bcb70a1a6f8f4e776e1ed427546b Mon Sep 17 00:00:00 2001 From: Ulrich Weigand Date: Tue, 24 Nov 2020 19:30:01 +0100 Subject: [PATCH] Revert: "Fix -ffast-math flags handling inconsistencies" This reverts commit c4fa3728ab4f78984a549894e0e8c4d6a253e540, which caused a regression in the default for flag_excess_precision. 2020-11-24 Ulrich Weigand gcc/ PR tree-optimization/97970 * doc/invoke.texi (-ffast-math): Revert last change. * opts.c: Revert last change. --- gcc/doc/invoke.texi | 6 ++--- gcc/opts.c | 58 ++++++++++++++++++++------------------------- 2 files changed, 29 insertions(+), 35 deletions(-) diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 896a3081a8b..26372a2435a 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -12342,10 +12342,10 @@ 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{-fcx-limited-range} and @option{-fexcess-precision=fast}. +@option{-fno-signaling-nans}, @option{-fcx-limited-range} and +@option{-fexcess-precision=fast}. -Whenever all these options listed above are set to those values, -the preprocessor macro @code{__FAST_MATH__} will be defined. +This option causes the preprocessor macro @code{__FAST_MATH__} to be defined. This option is not turned on by any @option{-O} option besides @option{-Ofast} since it can result in incorrect output for programs diff --git a/gcc/opts.c b/gcc/opts.c index 1a3fb892a71..57774916a09 100644 --- a/gcc/opts.c +++ b/gcc/opts.c @@ -193,12 +193,10 @@ static void set_debug_level (enum debug_info_type type, int extended, const char *arg, struct gcc_options *opts, struct gcc_options *opts_set, location_t loc); -static void set_fast_math_flags (struct gcc_options *opts, - struct gcc_options *opts_set, int set); +static void set_fast_math_flags (struct gcc_options *opts, int set); static void decode_d_option (const char *arg, struct gcc_options *opts, location_t loc, diagnostic_context *dc); static void set_unsafe_math_optimizations_flags (struct gcc_options *opts, - struct gcc_options *opts_set, int set); static void enable_warning_as_error (const char *arg, int value, unsigned int lang_mask, @@ -2493,11 +2491,11 @@ common_handle_option (struct gcc_options *opts, break; case OPT_ffast_math: - set_fast_math_flags (opts, opts_set, value); + set_fast_math_flags (opts, value); break; case OPT_funsafe_math_optimizations: - set_unsafe_math_optimizations_flags (opts, opts_set, value); + set_unsafe_math_optimizations_flags (opts, value); break; case OPT_ffixed_: @@ -2878,44 +2876,44 @@ set_Wstrict_aliasing (struct gcc_options *opts, int onoff) /* The following routines are useful in setting all the flags that -ffast-math and -fno-fast-math imply. */ static void -set_fast_math_flags (struct gcc_options *opts, - struct gcc_options *opts_set, int set) +set_fast_math_flags (struct gcc_options *opts, int set) { - if (!opts->frontend_set_flag_unsafe_math_optimizations - && !opts_set->x_flag_unsafe_math_optimizations) + if (!opts->frontend_set_flag_unsafe_math_optimizations) { opts->x_flag_unsafe_math_optimizations = set; - set_unsafe_math_optimizations_flags (opts, opts_set, set); + set_unsafe_math_optimizations_flags (opts, set); } if (!opts->frontend_set_flag_finite_math_only) - SET_OPTION_IF_UNSET (opts, opts_set, flag_finite_math_only, set); + opts->x_flag_finite_math_only = set; if (!opts->frontend_set_flag_errno_math) - SET_OPTION_IF_UNSET (opts, opts_set, flag_errno_math, !set); - if (!opts->frontend_set_flag_cx_limited_range) - SET_OPTION_IF_UNSET (opts, opts_set, flag_cx_limited_range, set); - if (!opts->frontend_set_flag_excess_precision) - SET_OPTION_IF_UNSET (opts, opts_set, flag_excess_precision, - set ? EXCESS_PRECISION_FAST - : EXCESS_PRECISION_DEFAULT); - - // -ffast-math should also reset -frounding-math, but since this - // is off by default, there's nothing to do for now. + opts->x_flag_errno_math = !set; + if (set) + { + if (opts->frontend_set_flag_excess_precision == EXCESS_PRECISION_DEFAULT) + opts->x_flag_excess_precision + = set ? EXCESS_PRECISION_FAST : EXCESS_PRECISION_DEFAULT; + if (!opts->frontend_set_flag_signaling_nans) + opts->x_flag_signaling_nans = 0; + if (!opts->frontend_set_flag_rounding_math) + opts->x_flag_rounding_math = 0; + if (!opts->frontend_set_flag_cx_limited_range) + opts->x_flag_cx_limited_range = 1; + } } /* When -funsafe-math-optimizations is set the following flags are set as well. */ static void -set_unsafe_math_optimizations_flags (struct gcc_options *opts, - struct gcc_options *opts_set, int set) +set_unsafe_math_optimizations_flags (struct gcc_options *opts, int set) { if (!opts->frontend_set_flag_trapping_math) - SET_OPTION_IF_UNSET (opts, opts_set, flag_trapping_math, !set); + opts->x_flag_trapping_math = !set; if (!opts->frontend_set_flag_signed_zeros) - SET_OPTION_IF_UNSET (opts, opts_set, flag_signed_zeros, !set); + opts->x_flag_signed_zeros = !set; if (!opts->frontend_set_flag_associative_math) - SET_OPTION_IF_UNSET (opts, opts_set, flag_associative_math, set); + opts->x_flag_associative_math = set; if (!opts->frontend_set_flag_reciprocal_math) - SET_OPTION_IF_UNSET (opts, opts_set, flag_reciprocal_math, set); + opts->x_flag_reciprocal_math = set; } /* Return true iff flags in OPTS are set as if -ffast-math. */ @@ -2923,14 +2921,10 @@ bool fast_math_flags_set_p (const struct gcc_options *opts) { return (!opts->x_flag_trapping_math - && !opts->x_flag_signed_zeros - && opts->x_flag_associative_math - && opts->x_flag_reciprocal_math && opts->x_flag_unsafe_math_optimizations && opts->x_flag_finite_math_only + && !opts->x_flag_signed_zeros && !opts->x_flag_errno_math - && !opts->x_flag_rounding_math - && opts->x_flag_cx_limited_range && opts->x_flag_excess_precision == EXCESS_PRECISION_FAST); } -- 2.30.2