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-rw-r--r--sysdeps/i386/fpu/e_powl.S25
1 files changed, 24 insertions, 1 deletions
diff --git a/sysdeps/i386/fpu/e_powl.S b/sysdeps/i386/fpu/e_powl.S
index 5d82571128..080764b84a 100644
--- a/sysdeps/i386/fpu/e_powl.S
+++ b/sysdeps/i386/fpu/e_powl.S
@@ -1,5 +1,6 @@
/* ix87 specific implementation of pow function.
- Copyright (C) 1996, 1997, 1998, 1999, 2001 Free Software Foundation, Inc.
+ Copyright (C) 1996, 1997, 1998, 1999, 2001, 2004
+ Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
@@ -48,6 +49,9 @@ one: .double 1.0
ASM_TYPE_DIRECTIVE(limit,@object)
limit: .double 0.29
ASM_SIZE_DIRECTIVE(limit)
+ ASM_TYPE_DIRECTIVE(p63,@object)
+p63: .byte 0, 0, 0, 0, 0, 0, 0xe0, 0x43
+ ASM_SIZE_DIRECTIVE(p63)
#ifdef PIC
#define MO(op) op##@GOTOFF(%ecx)
@@ -96,6 +100,14 @@ ENTRY(__ieee754_powl)
fxch // y : x
+ /* fistpll raises invalid exception for |y| >= 1L<<63. */
+ fld %st // y : y : x
+ fabs // |y| : y : x
+ fcompl MO(p63) // y : x
+ fnstsw
+ sahf
+ jnc 2f
+
/* First see whether `y' is a natural number. In this case we
can use a more precise algorithm. */
fld %st // y : y : x
@@ -161,6 +173,11 @@ ENTRY(__ieee754_powl)
7: fyl2x // log2(x) : y
8: fmul %st(1) // y*log2(x) : y
+ fxam
+ fnstsw
+ andb $0x45, %ah
+ cmpb $0x05, %ah // is y*log2(x) == ±inf ?
+ je 28f
fst %st(1) // y*log2(x) : y*log2(x)
frndint // int(y*log2(x)) : y*log2(x)
fsubr %st, %st(1) // int(y*log2(x)) : fract(y*log2(x))
@@ -172,6 +189,12 @@ ENTRY(__ieee754_powl)
fstp %st(1) // 2^fract(y*log2(x))*2^int(y*log2(x))
ret
+28: fstp %st(1) // y*log2(x)
+ fldl MO(one) // 1 : y*log2(x)
+ fscale // 2^(y*log2(x)) : y*log2(x)
+ addl $8, %esp
+ fstp %st(1) // 2^(y*log2(x))
+ ret
// pow(x,±0) = 1
.align ALIGNARG(4)