diff options
| -rw-r--r-- | configure.in | 3 | ||||
| -rw-r--r-- | insns.def | 18 | ||||
| -rw-r--r-- | internal.h | 47 | ||||
| -rw-r--r-- | numeric.c | 20 |
4 files changed, 54 insertions, 34 deletions
diff --git a/configure.in b/configure.in index 6558122797..05791864bb 100644 --- a/configure.in +++ b/configure.in @@ -2498,6 +2498,9 @@ RUBY_CHECK_BUILTIN_FUNC(__builtin_clzl, [__builtin_clzl(0)]) RUBY_CHECK_BUILTIN_FUNC(__builtin_clzll, [__builtin_clzll(0)]) RUBY_CHECK_BUILTIN_FUNC(__builtin_ctz, [__builtin_ctz(0)]) RUBY_CHECK_BUILTIN_FUNC(__builtin_ctzll, [__builtin_ctzll(0)]) +RUBY_CHECK_BUILTIN_FUNC(__builtin_add_ovewflow, [__builtin_add_ovewflow(0)]) +RUBY_CHECK_BUILTIN_FUNC(__builtin_sub_ovewflow, [__builtin_sub_ovewflow(0)]) +RUBY_CHECK_BUILTIN_FUNC(__builtin_mul_ovewflow, [__builtin_mul_ovewflow(0)]) RUBY_CHECK_BUILTIN_FUNC(__builtin_constant_p, [__builtin_constant_p(0)]) RUBY_CHECK_BUILTIN_FUNC(__builtin_choose_expr, [ [int x[__extension__(__builtin_choose_expr(1, 1, -1))]]; @@ -1373,16 +1373,7 @@ opt_plus { if (FIXNUM_2_P(recv, obj) && BASIC_OP_UNREDEFINED_P(BOP_PLUS,INTEGER_REDEFINED_OP_FLAG)) { - /* fixnum + fixnum */ -#ifndef LONG_LONG_VALUE - VALUE msb = (VALUE)1 << ((sizeof(VALUE) * CHAR_BIT) - 1); - val = recv - 1 + obj; - if ((~(recv ^ obj) & (recv ^ val)) & msb) { - val = rb_int2big((SIGNED_VALUE)((val>>1) | (recv & msb))); - } -#else - val = LONG2NUM(FIX2LONG(recv) + FIX2LONG(obj)); -#endif + val = rb_fix_plus_fix(recv, obj); } else if (FLONUM_2_P(recv, obj) && BASIC_OP_UNREDEFINED_P(BOP_PLUS, FLOAT_REDEFINED_OP_FLAG)) { @@ -1426,12 +1417,7 @@ opt_minus { if (FIXNUM_2_P(recv, obj) && BASIC_OP_UNREDEFINED_P(BOP_MINUS, INTEGER_REDEFINED_OP_FLAG)) { - long a, b, c; - - a = FIX2LONG(recv); - b = FIX2LONG(obj); - c = a - b; - val = LONG2NUM(c); + val = rb_fix_minus_fix(recv, obj); } else if (FLONUM_2_P(recv, obj) && BASIC_OP_UNREDEFINED_P(BOP_MINUS, FLOAT_REDEFINED_OP_FLAG)) { diff --git a/internal.h b/internal.h index 3e5550f4ca..4ed1e41440 100644 --- a/internal.h +++ b/internal.h @@ -348,6 +348,53 @@ VALUE rb_int128t2big(int128_t n); #define ST2FIX(h) LONG2FIX((long)(h)) +static inline unsigned long +rb_ulong_rotate_right(unsigned long x) +{ + return (x >> 1) | (x << (SIZEOF_LONG * CHAR_BIT - 1)); +} + +static inline VALUE +rb_fix_plus_fix(VALUE x, VALUE y) +{ +#ifdef HAVE_BUILTIN___BUILTIN_ADD_OVERFLOW + long lz; + /* NOTE + * (1) Fixnum's LSB is always 1. + * It means you can always run `x - 1` without overflow. + * (2) Of course `z = x + (y-1)` may overflow. + * Now z's LSB is always 1, and the MSB of true result is also 1. + * You can get true result in long as `(1<<63)|(z>>1)`, + * and it equals to `(z<<63)|(z>>1)` == `ror(z)`. + */ + if (__builtin_add_overflow((long)x, (long)y-1, &lz)) { + return rb_int2big(rb_ulong_rotate_right((unsigned long)lz)); + } + else { + return (VALUE)lz; + } +#else + long lz = FIX2LONG(x) + FIX2LONG(y); + return LONG2NUM(lz); +#endif +} + +static inline VALUE +rb_fix_minus_fix(VALUE x, VALUE y) +{ +#ifdef HAVE_BUILTIN___BUILTIN_SUB_OVERFLOW + long lz; + if (__builtin_sub_overflow((long)x, (long)y-1, &lz)) { + return rb_int2big(rb_ulong_rotate_right((unsigned long)lz)); + } + else { + return (VALUE)lz; + } +#else + long lz = FIX2LONG(x) - FIX2LONG(y); + return LONG2NUM(lz); +#endif +} /* arguments must be Fixnum */ static inline VALUE @@ -3458,15 +3458,7 @@ static VALUE fix_plus(VALUE x, VALUE y) { if (FIXNUM_P(y)) { - long a, b, c; - VALUE r; - - a = FIX2LONG(x); - b = FIX2LONG(y); - c = a + b; - r = LONG2NUM(c); - - return r; + return rb_fix_plus_fix(x, y); } else if (RB_TYPE_P(y, T_BIGNUM)) { return rb_big_plus(y, x); @@ -3513,15 +3505,7 @@ static VALUE fix_minus(VALUE x, VALUE y) { if (FIXNUM_P(y)) { - long a, b, c; - VALUE r; - - a = FIX2LONG(x); - b = FIX2LONG(y); - c = a - b; - r = LONG2NUM(c); - - return r; + return rb_fix_minus_fix(x, y); } else if (RB_TYPE_P(y, T_BIGNUM)) { x = rb_int2big(FIX2LONG(x)); |