1/*
2 * Public domain.
3 */
4
5#include <machine/asm.h>
6#include <i386-math-asm.h>
7#include <libm-alias-finite.h>
8
9DEFINE_DBL_MIN
10
11#ifdef PIC
12# define MO(op) op##@GOTOFF(%ecx)
13#else
14# define MO(op) op
15#endif
16
17	.text
18ENTRY(__ieee754_exp2)
19#ifdef  PIC
20	LOAD_PIC_REG (cx)
21#endif
22	fldl	4(%esp)
23/* I added the following ugly construct because exp(+-Inf) resulted
24   in NaN.  The ugliness results from the bright minds at Intel.
25   For the i686 the code can be written better.
26   -- drepper@cygnus.com.  */
27	fxam				/* Is NaN or +-Inf?  */
28	fstsw	%ax
29	movb	$0x45, %dh
30	andb	%ah, %dh
31	cmpb	$0x05, %dh
32	je	1f			/* Is +-Inf, jump.  */
33	fld	%st
34	frndint				/* int(x) */
35	fsubr	%st,%st(1)		/* fract(x) */
36	fxch
37	f2xm1				/* 2^(fract(x)) - 1 */
38	fld1
39	faddp				/* 2^(fract(x)) */
40	fscale				/* e^x */
41	fstp	%st(1)
42	DBL_NARROW_EVAL_UFLOW_NONNEG_NAN
43	ret
44
451:	testl	$0x200, %eax		/* Test sign.  */
46	jz	2f			/* If positive, jump.  */
47	fstp	%st
48	fldz				/* Set result to 0.  */
492:	ret
50END (__ieee754_exp2)
51libm_alias_finite (__ieee754_exp2, __exp2)
52