optimize scalbn family

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

diff --git a/src/math/i386/scalbn.s b/src/math/i386/scalbn.s
index e275d14..8bf302f 100644 (file)
--- a/src/math/i386/scalbn.s
+++ b/src/math/i386/scalbn.s
@@ -11,10 +11,23 @@ scalbln:
 .global scalbn
 .type scalbn,@function
 scalbn:
-       fildl 12(%esp)
+       mov 12(%esp),%eax
+       add $0x3ffe,%eax
+       cmp $0x7ffd,%eax
+       jb 1f
+       sub $0x3ffe,%eax
+       sar $31,%eax
+       xor $0xfff,%eax
+       add $0x3ffe,%eax
+1:     inc %eax
        fldl 4(%esp)
-       fscale
-       fstp %st(1)
+       mov %eax,12(%esp)
+       mov $0x80000000,%eax
+       mov %eax,8(%esp)
+       xor %eax,%eax
+       mov %eax,4(%esp)
+       fldt 4(%esp)
+       fmulp
        fstpl 4(%esp)
        fldl 4(%esp)
        ret