X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fmath%2Fi386%2Fexp.s;h=c7f5ad0fc0cc3cdc458db86a0fd6d3219a778583;hp=f4769d59c1ee499beacc8df5974ab45be60b9c8b;hb=1fb01691547e85be253a4f1543be3920de651e27;hpb=aa1b4dff45788f8205e32ea01da243fe09568aa8

diff --git a/src/math/i386/exp.s b/src/math/i386/exp.s
index f4769d59..c7f5ad0f 100644
--- a/src/math/i386/exp.s
+++ b/src/math/i386/exp.s
@@ -1,3 +1,37 @@
+.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:
@@ -34,22 +68,49 @@ exp:
 .type exp2,@function
 exp2:
 	fldl 4(%esp)
-1:	fxam
-	fnstsw %ax
+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
-	jnp 1f
-	jnc 1f
-	fstps 4(%esp)
-	mov $0xfe,%al
-	and %al,7(%esp)
-	flds 4(%esp)
-1:	fld %st(0)
-	frndint
+	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
-	fscale
+	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