x86_64 assembly language generated for MRI rb_obj_not (object.c line 186) with modified RTEST macro

gistfile1.txt

-- Change RTEST:

//#define RTEST(v) !(((VALUE)(v) & ~Qnil) == 0)
#define RTEST(v) ((VALUE)(v) != Qnil && (VALUE)(v))

-- Recompile with -S flag:

clang -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Werror=pointer-arith -Werror=write-strings -Werror=declaration-after-statement -Werror=shorten-64-to-32 -Werror=implicit-function-declaration -Werror=division-by-zero -Werror=extra-tokens -pipe -D_FORTIFY_SOURCE=2 -fstack-protector -fno-strict-overflow -fvisibility=hidden -DRUBY_EXPORT -fPIE -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -D_DARWIN_UNLIMITED_SELECT -D_REENTRANT -I. -I.ext/include/x86_64-darwin12.0 -I./include -I. -S -o object.o -c object.c

-- And here's the new assembly language - it's longer with a condition in the middle (See: je	LBB7_2)

_rb_obj_not:                            ## @rb_obj_not
	.cfi_startproc
Lfunc_begin7:
	.loc	1 185 0                 ## object.c:185:0
## BB#0:
	pushq	%rbp
Ltmp99:
	.cfi_def_cfa_offset 16
Ltmp100:
	.cfi_offset %rbp, -16
	movq	%rsp, %rbp
Ltmp101:
	.cfi_def_cfa_register %rbp
	##DEBUG_VALUE: rb_obj_not:obj <- RDI+0
	movl	$20, %eax
	cmpq	$8, %rdi
	je	LBB7_2
## BB#1:
Ltmp102:
	##DEBUG_VALUE: rb_obj_not:obj <- RDI+0
	xorl	%ecx, %ecx
	movl	$20, %eax
	.loc	1 186 0 prologue_end    ## object.c:186:0
Ltmp103:
	testq	%rdi, %rdi
	cmovneq	%rcx, %rax
Ltmp104:
LBB7_2:
	.loc	1 187 0                 ## object.c:187:0
	popq	%rbp
	ret
Ltmp105:
Lfunc_end7:
	.cfi_endproc