remquo asm: return quotient mod 8, as intended by the spec

[musl] / src / math / i386 / exp.s

diff --git a/src/math/i386/exp.s b/src/math/i386/exp.s
index f4769d5..ca0de1d 100644 (file)
--- 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:
@@ -34,15 +68,44 @@ exp:
 .type exp2,@function
 exp2:
        fldl 4(%esp)
-1:     fxam
-       fnstsw %ax
+1:     pushl $0x467ff000
+       flds (%esp)
+       xorl %eax,%eax
+       pushl $0x80000000
+       push %eax
+       fld %st(1)
+       fabs
+       fucom %st(1)
+       fnstsw
+       fstp %st(0)
+       fstp %st(0)
        sahf
-       jnp 1f
-       jnc 1f
-       fstps 4(%esp)
-       mov $0xfe,%al
-       and %al,7(%esp)
-       flds 4(%esp)
+       ja 2f
+       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
+       fldt (%esp)
+       fmulp
+       fstp %st(1)
+       add $12,%esp
+       ret
+
+2:     fld %st(0)
+       fstpt (%esp)
+       mov 9(%esp),%ah
+       and $0x7f,%ah
+       cmp $0x7f,%ah
+       jne 1f
+       decb 9(%esp)
+       fstp %st(0)
+       fldt (%esp)
 1:     fld %st(0)
        frndint
        fxch %st(1)
@@ -52,4 +115,5 @@ exp2:
        faddp
        fscale
        fstp %st(1)
+       add $12,%esp
        ret