s_sinl.s

来自「glibc 库, 不仅可以学习使用库函数,还可以学习函数的具体实现,是提高功力的」· S 代码 · 共 31 行

/*
 * Written by J.T. Conklin <[e-mail]>.
 * Public domain.
 *
 * Adapted for `long double' by Ulrich Drepper <[e-mail]>.
 * Adapted for x86-64 by Andreas Jaeger <[e-mail]>.
 */

#include <machine/asm.h>

ENTRY(__sinl)
	fldt	8(%rsp)
	fsin
	fnstsw	%ax
	testl	$0x400,%eax
	jnz	1f
	ret
	.align ALIGNARG(4)
1:	fldpi
	fadd	%st(0)
	fxch	%st(1)
2:	fprem1
	fnstsw	%ax
	testl	$0x400,%eax
	jnz	2b
	fstp	%st(1)
	fsin
	ret
END (__sinl)
weak_alias (__sinl, sinl)