e_powl-x86.S revision 4eea10ee035622d6ca422509072f0c4bfe4be09d
/* ix87 specific implementation of pow function.
Copyright (C) 1996, 1997, 1998, 1999, 2001, 2004, 2005
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/*#include <machine/asm.h>*/
#include <iprt/cdefs.h>
#ifdef __MINGW32__
# define ASM_TYPE_DIRECTIVE(name,typearg)
# define ASM_SIZE_DIRECTIVE(name)
# define cfi_adjust_cfa_offset(a)
# define C_LABEL(name) _ ## name:
# define C_SYMBOL_NAME(name) _ ## name
# define ASM_GLOBAL_DIRECTIVE .global
# define ALIGNARG(log2) 1<<log2
#elif __APPLE__
# define ASM_TYPE_DIRECTIVE(name,typearg)
# define ASM_SIZE_DIRECTIVE(name)
# define cfi_adjust_cfa_offset(a)
# define C_LABEL(name) _ ## name:
# define C_SYMBOL_NAME(name) _ ## name
# define ASM_GLOBAL_DIRECTIVE .globl
# define ALIGNARG(log2) log2
#else
# define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
# define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
# define C_LABEL(name) name:
# define C_SYMBOL_NAME(name) name
# /* figure this one out. */
# define cfi_adjust_cfa_offset(a)
# define ASM_GLOBAL_DIRECTIVE .global
# define ALIGNARG(log2) 1<<log2
#endif
#define ENTRY(name) \
ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function) \
.align ALIGNARG(4); \
C_LABEL(name)
#undef END
#define END(name) \
ASM_SIZE_DIRECTIVE(name)
#ifdef __ELF__
.section .rodata
#else
.text
#endif
.align ALIGNARG(4)
ASM_TYPE_DIRECTIVE(infinity,@object)
inf_zero:
infinity:
.byte 0, 0, 0, 0, 0, 0, 0xf0, 0x7f
ASM_SIZE_DIRECTIVE(infinity)
ASM_TYPE_DIRECTIVE(zero,@object)
zero: .double 0.0
ASM_SIZE_DIRECTIVE(zero)
ASM_TYPE_DIRECTIVE(minf_mzero,@object)
minf_mzero:
minfinity:
.byte 0, 0, 0, 0, 0, 0, 0xf0, 0xff
mzero:
.byte 0, 0, 0, 0, 0, 0, 0, 0x80
ASM_SIZE_DIRECTIVE(minf_mzero)
ASM_TYPE_DIRECTIVE(one,@object)
one: .double 1.0
ASM_SIZE_DIRECTIVE(one)
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)
#define MOX(op,x,f) op##@GOTOFF(%ecx,x,f)
#else
#define MO(op) op
#define MOX(op,x,f) op(,x,f)
#endif
.text
//ENTRY(__ieee754_powl)
ENTRY(RT_NOCRT(powl))
#ifdef RT_OS_DARWIN /* 16-byte long double with 8 byte alignment requirements */
fldt 20(%esp) // y
#else
fldt 16(%esp) // y
#endif
fxam
#ifdef PIC
LOAD_PIC_REG (cx)
#endif
fnstsw
movb %ah, %dl
andb $0x45, %ah
cmpb $0x40, %ah // is y == 0 ?
je .L11
cmpb $0x05, %ah // is y == �inf ?
je .L12
cmpb $0x01, %ah // is y == NaN ?
je .L30
fldt 4(%esp) // x : y
subl $8,%esp
cfi_adjust_cfa_offset (8)
fxam
fnstsw
movb %ah, %dh
andb $0x45, %ah
cmpb $0x40, %ah
je .L20 // x is �0
cmpb $0x05, %ah
je .L15 // x is �inf
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 .L2
/* First see whether `y' is a natural number. In this case we
can use a more precise algorithm. */
fld %st // y : y : x
fistpll (%esp) // y : x
fildll (%esp) // int(y) : y : x
fucomp %st(1) // y : x
fnstsw
sahf
jne .L2
/* OK, we have an integer value for y. */
popl %eax
cfi_adjust_cfa_offset (-4)
popl %edx
cfi_adjust_cfa_offset (-4)
orl $0, %edx
fstp %st(0) // x
jns .L4 // y >= 0, jump
fdivrl MO(one) // 1/x (now referred to as x)
negl %eax
adcl $0, %edx
negl %edx
.L4: fldl MO(one) // 1 : x
fxch
.L6: shrdl $1, %edx, %eax
jnc .L5
fxch
fmul %st(1) // x : ST*x
fxch
.L5: fmul %st(0), %st // x*x : ST*x
shrl $1, %edx
movl %eax, %ecx
orl %edx, %ecx
jnz .L6
fstp %st(0) // ST*x
ret
/* y is �NAN */
.L30: fldt 4(%esp) // x : y
fldl MO(one) // 1.0 : x : y
fucomp %st(1) // x : y
fnstsw
sahf
je .L31
fxch // y : x
.L31: fstp %st(1)
ret
cfi_adjust_cfa_offset (8)
.align ALIGNARG(4)
.L2: /* y is a real number. */
fxch // x : y
fldl MO(one) // 1.0 : x : y
fld %st(1) // x : 1.0 : x : y
fsub %st(1) // x-1 : 1.0 : x : y
fabs // |x-1| : 1.0 : x : y
fcompl MO(limit) // 1.0 : x : y
fnstsw
fxch // x : 1.0 : y
sahf
ja .L7
fsub %st(1) // x-1 : 1.0 : y
fyl2xp1 // log2(x) : y
jmp .L8
.L7: fyl2x // log2(x) : y
.L8: fmul %st(1) // y*log2(x) : y
fxam
fnstsw
andb $0x45, %ah
cmpb $0x05, %ah // is y*log2(x) == �inf ?
je .L28
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))
fxch // fract(y*log2(x)) : int(y*log2(x))
f2xm1 // 2^fract(y*log2(x))-1 : int(y*log2(x))
faddl MO(one) // 2^fract(y*log2(x)) : int(y*log2(x))
fscale // 2^fract(y*log2(x))*2^int(y*log2(x)) : int(y*log2(x))
addl $8, %esp
cfi_adjust_cfa_offset (-8)
fstp %st(1) // 2^fract(y*log2(x))*2^int(y*log2(x))
ret
cfi_adjust_cfa_offset (8)
.L28: fstp %st(1) // y*log2(x)
fldl MO(one) // 1 : y*log2(x)
fscale // 2^(y*log2(x)) : y*log2(x)
addl $8, %esp
cfi_adjust_cfa_offset (-8)
fstp %st(1) // 2^(y*log2(x))
ret
// pow(x,�0) = 1
.align ALIGNARG(4)
.L11: fstp %st(0) // pop y
fldl MO(one)
ret
// y == �inf
.align ALIGNARG(4)
.L12: fstp %st(0) // pop y
fldt 4(%esp) // x
fabs
fcompl MO(one) // < 1, == 1, or > 1
fnstsw
andb $0x45, %ah
cmpb $0x45, %ah
je .L13 // jump if x is NaN
cmpb $0x40, %ah
je .L14 // jump if |x| == 1
shlb $1, %ah
xorb %ah, %dl
andl $2, %edx
fldl MOX(inf_zero, %edx, 4)
ret
.align ALIGNARG(4)
.L14: fldl MO(one)
ret
.align ALIGNARG(4)
.L13: fldt 4(%esp) // load x == NaN
ret
cfi_adjust_cfa_offset (8)
.align ALIGNARG(4)
// x is �inf
.L15: fstp %st(0) // y
testb $2, %dh
jz .L16 // jump if x == +inf
// We must find out whether y is an odd integer.
fld %st // y : y
fistpll (%esp) // y
fildll (%esp) // int(y) : y
fucompp // <empty>
fnstsw
sahf
jne .L17
// OK, the value is an integer, but is it odd?
popl %eax
cfi_adjust_cfa_offset (-4)
popl %edx
cfi_adjust_cfa_offset (-4)
andb $1, %al
jz .L18 // jump if not odd
// It's an odd integer.
shrl $31, %edx
fldl MOX(minf_mzero, %edx, 8)
ret
cfi_adjust_cfa_offset (8)
.align ALIGNARG(4)
.L16: fcompl MO(zero)
addl $8, %esp
cfi_adjust_cfa_offset (-8)
fnstsw
shrl $5, %eax
andl $8, %eax
fldl MOX(inf_zero, %eax, 1)
ret
cfi_adjust_cfa_offset (8)
.align ALIGNARG(4)
.L17: shll $30, %edx // sign bit for y in right position
addl $8, %esp
cfi_adjust_cfa_offset (-8)
.L18: shrl $31, %edx
fldl MOX(inf_zero, %edx, 8)
ret
cfi_adjust_cfa_offset (8)
.align ALIGNARG(4)
// x is �0
.L20: fstp %st(0) // y
testb $2, %dl
jz .L21 // y > 0
// x is �0 and y is < 0. We must find out whether y is an odd integer.
testb $2, %dh
jz .L25
fld %st // y : y
fistpll (%esp) // y
fildll (%esp) // int(y) : y
fucompp // <empty>
fnstsw
sahf
jne .L26
// OK, the value is an integer, but is it odd?
popl %eax
cfi_adjust_cfa_offset (-4)
popl %edx
cfi_adjust_cfa_offset (-4)
andb $1, %al
jz .L27 // jump if not odd
// It's an odd integer.
// Raise divide-by-zero exception and get minus infinity value.
fldl MO(one)
fdivl MO(zero)
fchs
ret
cfi_adjust_cfa_offset (8)
.L25: fstp %st(0)
.L26: addl $8, %esp
cfi_adjust_cfa_offset (-8)
.L27: // Raise divide-by-zero exception and get infinity value.
fldl MO(one)
fdivl MO(zero)
ret
cfi_adjust_cfa_offset (8)
.align ALIGNARG(4)
// x is �0 and y is > 0. We must find out whether y is an odd integer.
.L21: testb $2, %dh
jz .L22
fld %st // y : y
fistpll (%esp) // y
fildll (%esp) // int(y) : y
fucompp // <empty>
fnstsw
sahf
jne .L23
// OK, the value is an integer, but is it odd?
popl %eax
cfi_adjust_cfa_offset (-4)
popl %edx
cfi_adjust_cfa_offset (-4)
andb $1, %al
jz .L24 // jump if not odd
// It's an odd integer.
fldl MO(mzero)
ret
cfi_adjust_cfa_offset (8)
.L22: fstp %st(0)
.L23: addl $8, %esp // Don't use 2 x pop
cfi_adjust_cfa_offset (-8)
.L24: fldl MO(zero)
ret
END(RT_NOCRT(powl))
//END(__ieee754_powl)