| Leopard | Snow Leopard |
|---|---|
// 107 instruction bytes _objc_msgSend: cmpq $0xfffffffffffeb010, %rsi if (_cmd is ignored) je IGNORED return self testq %rdi, %rdi if (self == nil) je NIL return zero movq (%rdi), %r11 class = self->isa movq %rcx, -32(%rsp) save non-volatile registers movq %r8, -24(%rsp) movq %r9, -16(%rsp) movq 16(%r11), %rcx cache = class->cache leaq 8(%rcx), %r8 buckets = cache->buckets movl (%rcx), %r9d mask = cache->mask shlq $3, %r9 mask *= 8 movq %rsi, %rcx andq %r9, %rcx offset = _cmd & mask LOOP: movq (%r8, %rcx), %r11 method = buckets[index] testq %r11, %r11 if (method == nil) je MISS goto cache miss addq $8, %rcx offset += 8 andq %r9, %rcx offset &= mask cmpq (%r11), %rsi if (method->sel != _cmd) jne LOOP scan more movq -32(%rsp), %rcx restore saved registers movq -24(%rsp), %r8 movq -16(%rsp), %r9 movq 16(%r11), %r11 imp = method->imp jmpq *%r11 jump to imp |
// 104 instruction bytes _objc_msgSend: cmpq $0xfffffffffffeb010, %rsi if (_cmd is ignored) je IGNORED return self testq %rdi, %rdi if (self == nil) je NIL return zero movq (%rdi), %r11 class = self->isa movq %rcx, -32(%rsp) save non-volatile registers movq %r8, -24(%rsp) movq %r9, -16(%rsp) movq 16(%r11), %r8 cache = class->cache movl (%r8), %r9d mask = cache->mask shlq $3, %r9 mask *= 8 movq %rsi, %rcx andq %r9, %rcx offset = _cmd & mask LOOP: movq 16(%r8, %rcx), %r11 method = cache->buckets[offset] testq %r11, %r11 if (method == nil) je MISS goto cache miss addq $8, %rcx offset += 8 andq %r9, %rcx offset &= mask cmpq (%r11), %rsi if (method->sel != _cmd) jne LOOP scan more movq -32(%rsp), %rcx restore saved registers movq -24(%rsp), %r8 movq -16(%rsp), %r9 movq 16(%r11), %r11 imp = method->imp cmpq %r11, %r11 set non-struct for forwarding jmpq *%r11 jump to imp |
Changes in Snow Leopard: