diff options
| author | shyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2017-03-06 06:04:52 +0000 |
|---|---|---|
| committer | shyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2017-03-06 06:04:52 +0000 |
| commit | 3106f9412ab7bd89cd9fd4931bb7b4865b892d78 (patch) | |
| tree | 508d56481df15bcd86ad634e7e25a19e6c55bc9a /internal.h | |
| parent | c8921b5ef07c3193d7b9ad6c329b8ade8bef8460 (diff) | |
use HAVE_BUILTIN___BUILTIN_MUL_OVERFLOW
We already check for __builtin_mul_overflow in configure but never
actually referred it before. Why not call it if available, because
that should render supposedly-optimial assembly outputs.
Optionally if __builtin_mul_overflow_p is available, which is the case
for recent GCC, use that to detect fixnum overflow. This is much
faster than the previous. On my machine generated assembly of
numeric.c:int_pow reduces from 480 to 448 bytes, according to nm(1).
Also on my machine, following script boosts from 7.819 to 6.929 sec.
time ./miniruby -e 'i=0; while i < 30_000_000 do i += 1; 7 ** 23; end'
Signed-off-by: Urabe, Shyouhei <shyouhei@ruby-lang.org>
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57784 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'internal.h')
| -rw-r--r-- | internal.h | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/internal.h b/internal.h index e74b91f667..eebd31073c 100644 --- a/internal.h +++ b/internal.h @@ -96,15 +96,41 @@ extern "C" { #endif #define TIMET_MAX_PLUS_ONE (2*(double)(TIMET_MAX/2+1)) +#ifdef HAVE_BUILTIN___BUILTIN_MUL_OVERFLOW_P +#define MUL_OVERFLOW_P(a, b) \ + __builtin_mul_overflow_p((a), (b), (__typeof__(a * b))0) +#elif defined HAVE_BUILTIN___BUILTIN_MUL_OVERFLOW +#define MUL_OVERFLOW_P(a, b) \ + ({__typeof__(a) c; __builtin_mul_overflow((a), (b), &c);}) +#endif + #define MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, min, max) ( \ (a) == 0 ? 0 : \ (a) == -1 ? (b) < -(max) : \ (a) > 0 ? \ ((b) > 0 ? (max) / (a) < (b) : (min) / (a) > (b)) : \ ((b) > 0 ? (min) / (a) < (b) : (max) / (a) > (b))) + +#ifdef HAVE_BUILTIN___BUILTIN_MUL_OVERFLOW_P +/* __builtin_mul_overflow_p can take bitfield */ +/* and GCC permits bitfields for integers other than int */ +#define MUL_OVERFLOW_FIXNUM_P(a, b) ({ \ + struct { SIGNED_VALUE fixnum : SIZEOF_VALUE * CHAR_BIT - 1; } c; \ + __builtin_mul_overflow_p((a), (b), c.fixnum); \ +}) +#else #define MUL_OVERFLOW_FIXNUM_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, FIXNUM_MIN, FIXNUM_MAX) -#define MUL_OVERFLOW_LONG_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, LONG_MIN, LONG_MAX) -#define MUL_OVERFLOW_INT_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, INT_MIN, INT_MAX) +#endif + +#ifdef MUL_OVERFLOW_P +#define MUL_OVERFLOW_LONG_LONG_P(a, b) MUL_OVERFLOW_P(a, b) +#define MUL_OVERFLOW_LONG_P(a, b) MUL_OVERFLOW_P(a, b) +#define MUL_OVERFLOW_INT_P(a, b) MUL_OVERFLOW_P(a, b) +#else +#define MUL_OVERFLOW_LONG_LONG_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, LONG_LONG_MIN, LONG_LONG_MAX) +#define MUL_OVERFLOW_LONG_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, LONG_MIN, LONG_MAX) +#define MUL_OVERFLOW_INT_P(a, b) MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, INT_MIN, INT_MAX) +#endif #ifndef swap16 # ifdef HAVE_BUILTIN___BUILTIN_BSWAP16 |