diff options
| -rw-r--r-- | ChangeLog | 15 | ||||
| -rw-r--r-- | insns.def | 17 |
2 files changed, 21 insertions, 11 deletions
@@ -1,3 +1,18 @@ +Tue Jun 28 02:41:32 2016 NARUSE, Yui <naruse@ruby-lang.org> + + * insns.def (opt_plus): use `- 1` instead of `& (~1)` to allow + compilers to use x86 LEA instruction (3 operand). + Even if 3 operand LEA's latency is 3 cycle after SandyBridge, + it reduces code size and can be faster because of super scalar. + + * insns.def (opt_plus): calculate and use rb_int2big. + On positive Fixnum overflow, `recv - 1 + obj` doesn't carry + because recv's msb and obj's msb are 0, and resulted msb is 1. + Therefore simply rshift and cast as signed long works fine. + On negative Fixnum overflow, it will carry because both arguments' + msb are 1, and resulted msb is also 1. + In this case it needs to restore carried sign bit after rshift. + Mon Jun 27 16:58:32 2016 Nobuyoshi Nakada <nobu@ruby-lang.org> * lib/fileutils.rb (FileUtils#install): accecpt symbolic mode, as @@ -1381,18 +1381,13 @@ opt_plus BASIC_OP_UNREDEFINED_P(BOP_PLUS,INTEGER_REDEFINED_OP_FLAG)) { /* fixnum + fixnum */ #ifndef LONG_LONG_VALUE - val = (recv + (obj & (~1))); - if ((~(recv ^ obj) & (recv ^ val)) & - ((VALUE)0x01 << ((sizeof(VALUE) * CHAR_BIT) - 1))) { - val = rb_big_plus(rb_int2big(FIX2LONG(recv)), - rb_int2big(FIX2LONG(obj))); - } + 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 - long a, b, c; - a = FIX2LONG(recv); - b = FIX2LONG(obj); - c = a + b; - val = LONG2NUM(c); + val = LONG2NUM(FIX2LONG(recv) + FIX2LONG(obj)); #endif } else if (FLONUM_2_P(recv, obj) && |