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/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*
* Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
* Adapted for x86-64 by Andreas Jaeger <aj@suse.de>
*
* Correct handling of y==-inf <drepper@gnu>
*/
#include <machine/asm.h>
RCSID("$NetBSD: $")
#ifdef __ELF__
.section .rodata
#else
.text
#endif
.align ALIGNARG(4)
ASM_TYPE_DIRECTIVE(zero_nan,@object)
zero_nan:
.double 0.0
nan: .byte 0, 0, 0, 0, 0, 0, 0xff, 0x7f
minus_zero:
.byte 0, 0, 0, 0, 0, 0, 0, 0x80
.byte 0, 0, 0, 0, 0, 0, 0xff, 0x7f
ASM_SIZE_DIRECTIVE(zero_nan)
#ifdef PIC
#define MO(op) op##(%rip)
#else
#define MO(op) op
#endif
.text
ENTRY(__ieee754_scalbl)
fldt 24(%rsp)
fxam
fnstsw
fldt 8(%rsp)
andl $0x4700, %eax
cmpl $0x0700, %eax
je 1f
andl $0x4500, %eax
cmpl $0x0100, %eax
je 2f
fxam
fnstsw
andl $0x4500, %eax
cmpl $0x0100, %eax
je 3f
fld %st(1)
frndint
fcomip %st(2), %st
jne 4f
fscale
fstp %st(1)
ret
/* y is -inf */
1: fxam
fnstsw
movl 16(%rsp), %edx
shrl $5, %eax
fstp %st
fstp %st
andl $0x8000, %edx
andl $8, %eax
jnz 4f
shrl $11, %edx
addl %edx, %eax
#ifdef PIC
lea zero_nan(%rip),%rdx
fldl (%rdx,%rax,1)
#else
fldl zero_nan(%rax, 1)
#endif
ret
/* The result is NaN, but we must not raise an exception.
So use a variable. */
2: fstp %st
fstp %st
fldl MO(nan)
ret
/* The first parameter is a NaN. Return it. */
3: fstp %st(1)
ret
/* Return NaN and raise the invalid exception. */
4: fstp %st
fstp %st
fldz
fdiv %st
ret
END(__ieee754_scalbl)
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