musl/src/math/i386/exp.s

.global expm1f
.type expm1f,@function
expm1f:
	flds 4(%esp)
	jmp 1f

.global expm1l
.type expm1l,@function
expm1l:
	fldt 4(%esp)
	jmp 1f

.global expm1
.type expm1,@function
expm1:
	fldl 4(%esp)
1:	fldl2e
	fmulp
	fld1
	fld %st(1)
	fabs
	fucom %st(1)
	fnstsw %ax
	fstp %st(0)
	fstp %st(0)
	sahf
	ja 1f
	f2xm1
	ret
1:	call 1f
	fld1
	fsubrp
	ret

.global exp2f
.type exp2f,@function
exp2f:
	flds 4(%esp)
	jmp 1f

.global exp2l
.type exp2l,@function
exp2l:
	fldt 4(%esp)
	jmp 1f

.global expf
.type expf,@function
expf:
	flds 4(%esp)
	jmp 2f

.global expl
.type expl,@function
expl:
	fldt 4(%esp)
	jmp 2f

.global exp
.type exp,@function
exp:
	fldl 4(%esp)
2:	fldl2e
	fmulp
	jmp 1f

.global exp2
.type exp2,@function
exp2:
	fldl 4(%esp)
1:	pushl $0x467ff000
	flds (%esp)       # 16380
	xorl %eax,%eax
	pushl $0x80000000
	push %eax
	fld %st(1)
	fabs
	fucomp %st(1)
	fnstsw
	fstp %st(0)
	sahf
	ja 3f             # |x| > 16380
	jp 2f             # x is nan (avoid invalid except in fistp)
	fld %st(0)
	fistpl 8(%esp)
	fildl 8(%esp)
	fxch %st(1)
	fsub %st(1)
	mov $0x3fff,%eax
	add %eax,8(%esp)
	f2xm1
	fld1
	faddp             # 2^(x-rint(x))
	fldt (%esp)       # 2^rint(x)
	fmulp
	fstp %st(1)
2:	add $12,%esp
	ret

3:	fld %st(0)
	fstpt (%esp)
	fld1
	mov 8(%esp),%ax
	and $0x7fff,%ax
	cmp $0x7fff,%ax
	je 1f             # x = +-inf
	fld %st(1)
	frndint
	fxch %st(2)
	fsub %st(2)       # st(0)=x-rint(x), st(1)=1, st(2)=rint(x)
	f2xm1
	faddp             # 2^(x-rint(x))
1:	fscale
	fstp %st(1)
	add $12,%esp
	ret