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| author | James Greenhalgh <james.greenhalgh@arm.com> | 2016-11-23 17:23:12 +0000 |
|---|---|---|
| committer | James Greenhalgh <jgreenhalgh@gcc.gnu.org> | 2016-11-23 17:23:12 +0000 |
| commit | 56d8ffc170912cb1dee5900799acaf5d4857fde9 (patch) | |
| tree | b2e05c11d31890a7a8ef669c3474d40a7843da1c /gcc/doc | |
| parent | 04f0fcf7bdfa1b4d153ca37df8843c44ed8c4d93 (diff) | |
| download | gcc-56d8ffc170912cb1dee5900799acaf5d4857fde9.zip gcc-56d8ffc170912cb1dee5900799acaf5d4857fde9.tar.gz gcc-56d8ffc170912cb1dee5900799acaf5d4857fde9.tar.bz2 | |
[Patch 6/17] Migrate excess precision logic to use TARGET_EXCESS_PRECISION
gcc/
* toplev.c (init_excess_precision): Delete most logic.
* tree.c (excess_precision_type): Rewrite to use
TARGET_EXCESS_PRECISION.
* doc/invoke.texi (-fexcess-precision): Document behaviour in a
more generic fashion.
* ginclude/float.h: Wrap definition of FLT_EVAL_METHOD in
__STDC_WANT_IEC_60559_TYPES_EXT__.
gcc/c-family/
* c-common.c (excess_precision_mode_join): New.
(c_ts18661_flt_eval_method): New.
(c_c11_flt_eval_method): Likewise.
(c_flt_eval_method): Likewise.
* c-common.h (excess_precision_mode_join): New.
(c_flt_eval_method): Likewise.
* c-cppbuiltin.c (c_cpp_flt_eval_method_iec_559): New.
(cpp_iec_559_value): Call it.
(c_cpp_builtins): Modify logic for __LIBGCC_*_EXCESS_PRECISION__,
call c_flt_eval_method to set __FLT_EVAL_METHOD__ and
__FLT_EVAL_METHOD_TS_18661_3__.
gcc/testsuite/
* gcc.dg/fpermitted-flt-eval-methods_3.c: New.
* gcc.dg/fpermitted-flt-eval-methods_4.c: Likewise.
From-SVN: r242776
Diffstat (limited to 'gcc/doc')
| -rw-r--r-- | gcc/doc/invoke.texi | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index a9d0609..22f539d 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -8987,15 +8987,14 @@ them to store all pertinent intermediate computations into variables. @item -fexcess-precision=@var{style} @opindex fexcess-precision This option allows further control over excess precision on machines -where floating-point registers have more precision than the IEEE -@code{float} and @code{double} types and the processor does not -support operations rounding to those types. By default, -@option{-fexcess-precision=fast} is in effect; this means that -operations are carried out in the precision of the registers and that -it is unpredictable when rounding to the types specified in the source -code takes place. When compiling C, if -@option{-fexcess-precision=standard} is specified then excess -precision follows the rules specified in ISO C99; in particular, +where floating-point operations occur in a format with more precision or +range than the IEEE standard and interchange floating-point types. By +default, @option{-fexcess-precision=fast} is in effect; this means that +operations may be carried out in a wider precision than the types specified +in the source if that would result in faster code, and it is unpredictable +when rounding to the types specified in the source code takes place. +When compiling C, if @option{-fexcess-precision=standard} is specified then +excess precision follows the rules specified in ISO C99; in particular, 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 |