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_LDBL_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_exp2l)
19#ifdef PIC
20	LOAD_PIC_REG (cx)
21#endif
22	fldt	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	movzwl	4+8(%esp), %eax
34	andl	$0x7fff, %eax
35	cmpl	$0x3fbe, %eax
36	jge	3f
37	/* Argument's exponent below -65, result rounds to 1.  */
38	fld1
39	faddp
40	ret
413:	fld	%st
42	frndint				/* int(x) */
43	fsubr	%st,%st(1)		/* fract(x) */
44	fxch
45	f2xm1				/* 2^(fract(x)) - 1 */
46	fld1
47	faddp				/* 2^(fract(x)) */
48	fscale				/* e^x */
49	fstp	%st(1)
50	LDBL_CHECK_FORCE_UFLOW_NONNEG_NAN
51	ret
52
531:	testl	$0x200, %eax		/* Test sign.  */
54	jz	2f			/* If positive, jump.  */
55	fstp	%st
56	fldz				/* Set result to 0.  */
572:	ret
58END (__ieee754_exp2l)
59libm_alias_finite (__ieee754_exp2l, __exp2l)
60