mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-13 00:30:07 +00:00
Optimized expf for x86-64
This commit is contained in:
Ulrich Drepper
parent
d40c5d54cb
commit
39adf059fc
@ -1,3 +1,8 @@
|
||||
2012-02-28 Ulrich Drepper <drepper@gmail.com>
|
||||
|
||||
* sysdeps/x86_64/fpu/e_expf.S: New file.
|
||||
Contributed by Dmitrieva Liubov <liubov.dmitrieva@gmail.com>.
|
||||
|
||||
2012-02-28 Stanislav Brabec <sbrabec@suse.cz>
|
||||
|
||||
[BZ #13637]
|
||||
@ -102,11 +107,9 @@
|
||||
|
||||
* configure.in (CC): Restrict allowed GCC versions to 4.3 and
|
||||
later. Allow versions 5-9.
|
||||
* configure: Regenerated.
|
||||
* manual/install.texi (Tools for Compilation): Give GCC 4.3 as
|
||||
required minimum version and 4.6 as recommended version. Do not
|
||||
mention bugs in GCC 2.7 and 2.8.
|
||||
* INSTALL: Regenerated.
|
||||
|
||||
2012-02-27 David S. Miller <davem@davemloft.net>
|
||||
|
||||
@ -144,7 +147,6 @@
|
||||
(Specific advice for GNU/Linux systems): Describe use of headers
|
||||
from "make headers_install", not private headers from older
|
||||
kernels.
|
||||
* INSTALL: Regenerated.
|
||||
* sysdeps/unix/sysv/linux/configure.in (LIBC_LINUX_VERSION):
|
||||
Change to 2.6.19.
|
||||
* sysdeps/unix/sysv/linux/configure: Regenerated.
|
||||
|
||||
340
sysdeps/x86_64/fpu/e_expf.S
Normal file
340
sysdeps/x86_64/fpu/e_expf.S
Normal file
@ -0,0 +1,340 @@
|
||||
/* Optimized __ieee754_expf function.
|
||||
Copyright (C) 2012 Free Software Foundation, Inc.
|
||||
Contributed by Intel Corporation.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
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 <sysdep.h>
|
||||
|
||||
/* Short algorithm description:
|
||||
*
|
||||
* Let K = 64 (table size).
|
||||
* e^x = 2^(x/log(2)) = 2^n * T[j] * (1 + P(y))
|
||||
* where
|
||||
* x = m*log(2)/K + y, y in [0.0..log(2)/K]
|
||||
* m = n*K + j, m,n,j - signed integer, j in [0..K-1]
|
||||
* values of 2^(j/K) are tabulated as T[j].
|
||||
*
|
||||
* P(y) is a minimax polynomial approximation of expf(x)-1
|
||||
* on small interval [0.0..log(2)/K].
|
||||
*
|
||||
* P(y) = P3*y*y*y*y + P2*y*y*y + P1*y*y + P0*y, calculated as
|
||||
* z = y*y; P(y) = (P3*z + P1)*z + (P2*z + P0)*y
|
||||
*
|
||||
* Special cases:
|
||||
* expf(NaN) = NaN
|
||||
* expf(+INF) = +INF
|
||||
* expf(-INF) = 0
|
||||
* expf(x) = 1 for subnormals
|
||||
* for finite argument, only expf(0)=1 is exact
|
||||
* expf(x) overflows if x>88.7228317260742190
|
||||
* expf(x) underflows if x<-103.972076416015620
|
||||
*/
|
||||
|
||||
.text
|
||||
ENTRY(__ieee754_expf)
|
||||
/* Input: single precision x in %xmm0 */
|
||||
cvtss2sd %xmm0, %xmm1 /* Convert x to double precision */
|
||||
movd %xmm0, %ecx /* Copy x */
|
||||
movsd L(DP_KLN2)(%rip), %xmm2 /* DP K/log(2) */
|
||||
movsd L(DP_P2)(%rip), %xmm3 /* DP P2 */
|
||||
movl %ecx, %eax /* x */
|
||||
mulsd %xmm1, %xmm2 /* DP x*K/log(2) */
|
||||
andl $0x7fffffff, %ecx /* |x| */
|
||||
lea L(DP_T)(%rip), %rsi /* address of table T[j] */
|
||||
cmpl $0x42ad496b, %ecx /* |x|<125*log(2) ? */
|
||||
movsd L(DP_P3)(%rip), %xmm4 /* DP P3 */
|
||||
addsd L(DP_RS)(%rip), %xmm2 /* DP x*K/log(2)+RS */
|
||||
jae L(special_paths)
|
||||
|
||||
/* Here if |x|<125*log(2) */
|
||||
cmpl $0x31800000, %ecx /* |x|<2^(-28) ? */
|
||||
jb L(small_arg)
|
||||
|
||||
/* Main path: here if 2^(-28)<=|x|<125*log(2) */
|
||||
cvtsd2ss %xmm2, %xmm2 /* SP x*K/log(2)+RS */
|
||||
movd %xmm2, %eax /* bits of n*K+j with trash */
|
||||
subss L(SP_RS)(%rip), %xmm2 /* SP t=round(x*K/log(2)) */
|
||||
movl %eax, %edx /* n*K+j with trash */
|
||||
cvtss2sd %xmm2, %xmm2 /* DP t */
|
||||
andl $0x3f, %eax /* bits of j */
|
||||
mulsd L(DP_NLN2K)(%rip), %xmm2/* DP -t*log(2)/K */
|
||||
andl $0xffffffc0, %edx /* bits of n */
|
||||
#ifdef __AVX__
|
||||
vaddsd %xmm1, %xmm2, %xmm0 /* DP y=x-t*log(2)/K */
|
||||
vmulsd %xmm0, %xmm0, %xmm2 /* DP z=y*y */
|
||||
#else
|
||||
addsd %xmm1, %xmm2 /* DP y=x-t*log(2)/K */
|
||||
movaps %xmm2, %xmm0 /* DP y */
|
||||
mulsd %xmm2, %xmm2 /* DP z=y*y */
|
||||
#endif
|
||||
mulsd %xmm2, %xmm4 /* DP P3*z */
|
||||
addl $0x1fc0, %edx /* bits of n + SP exponent bias */
|
||||
mulsd %xmm2, %xmm3 /* DP P2*z */
|
||||
shll $17, %edx /* SP 2^n */
|
||||
addsd L(DP_P1)(%rip), %xmm4 /* DP P3*z+P1 */
|
||||
addsd L(DP_P0)(%rip), %xmm3 /* DP P2*z+P0 */
|
||||
movd %edx, %xmm1 /* SP 2^n */
|
||||
mulsd %xmm2, %xmm4 /* DP (P3*z+P1)*z */
|
||||
mulsd %xmm3, %xmm0 /* DP (P2*z+P0)*y */
|
||||
addsd %xmm4, %xmm0 /* DP P(y) */
|
||||
mulsd (%rsi,%rax,8), %xmm0 /* DP P(y)*T[j] */
|
||||
addsd (%rsi,%rax,8), %xmm0 /* DP T[j]*(P(y)+1) */
|
||||
cvtsd2ss %xmm0, %xmm0 /* SP T[j]*(P(y)+1) */
|
||||
mulss %xmm1, %xmm0 /* SP result=2^n*(T[j]*(P(y)+1)) */
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(small_arg):
|
||||
/* Here if 0<=|x|<2^(-28) */
|
||||
addss L(SP_ONE)(%rip), %xmm0 /* 1.0 + x */
|
||||
/* Return 1.0 with inexact raised, except for x==0 */
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(special_paths):
|
||||
/* Here if 125*log(2)<=|x| */
|
||||
shrl $31, %eax /* Get sign bit of x, and depending on it: */
|
||||
lea L(SP_RANGE)(%rip), %rdx /* load over/underflow bound */
|
||||
cmpl (%rdx,%rax,4), %ecx /* |x|<under/overflow bound ? */
|
||||
jbe L(near_under_or_overflow)
|
||||
|
||||
/* Here if |x|>under/overflow bound */
|
||||
cmpl $0x7f800000, %ecx /* |x| is finite ? */
|
||||
jae L(arg_inf_or_nan)
|
||||
|
||||
/* Here if |x|>under/overflow bound, and x is finite */
|
||||
testq %rax, %rax /* sign of x nonzero ? */
|
||||
je L(res_overflow)
|
||||
|
||||
/* Here if -inf<x<underflow bound (x<0) */
|
||||
movss L(SP_SMALL)(%rip), %xmm0/* load small value 2^(-100) */
|
||||
mulss %xmm0, %xmm0 /* Return underflowed result (zero or subnormal) */
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(res_overflow):
|
||||
/* Here if overflow bound<x<inf (x>0) */
|
||||
movss L(SP_LARGE)(%rip), %xmm0/* load large value 2^100 */
|
||||
mulss %xmm0, %xmm0 /* Return overflowed result (Inf or max normal) */
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(arg_inf_or_nan):
|
||||
/* Here if |x| is Inf or NAN */
|
||||
jne L(arg_nan) /* |x| is Inf ? */
|
||||
|
||||
/* Here if |x| is Inf */
|
||||
lea L(SP_INF_0)(%rip), %rdx /* depending on sign of x: */
|
||||
movss (%rdx,%rax,4), %xmm0 /* return zero or Inf */
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(arg_nan):
|
||||
/* Here if |x| is NaN */
|
||||
addss %xmm0, %xmm0 /* Return x+x (raise invalid) */
|
||||
ret
|
||||
|
||||
.p2align 4
|
||||
L(near_under_or_overflow):
|
||||
/* Here if 125*log(2)<=|x|<under/overflow bound */
|
||||
cvtsd2ss %xmm2, %xmm2 /* SP x*K/log(2)+RS */
|
||||
movd %xmm2, %eax /* bits of n*K+j with trash */
|
||||
subss L(SP_RS)(%rip), %xmm2 /* SP t=round(x*K/log(2)) */
|
||||
movl %eax, %edx /* n*K+j with trash */
|
||||
cvtss2sd %xmm2, %xmm2 /* DP t */
|
||||
andl $0x3f, %eax /* bits of j */
|
||||
mulsd L(DP_NLN2K)(%rip), %xmm2/* DP -t*log(2)/K */
|
||||
andl $0xffffffc0, %edx /* bits of n */
|
||||
#ifdef __AVX__
|
||||
vaddsd %xmm1, %xmm2, %xmm0 /* DP y=x-t*log(2)/K */
|
||||
vmulsd %xmm0, %xmm0, %xmm2 /* DP z=y*y */
|
||||
#else
|
||||
addsd %xmm1, %xmm2 /* DP y=x-t*log(2)/K */
|
||||
movaps %xmm2, %xmm0 /* DP y */
|
||||
mulsd %xmm2, %xmm2 /* DP z=y*y */
|
||||
#endif
|
||||
mulsd %xmm2, %xmm4 /* DP P3*z */
|
||||
addl $0xffc0, %edx /* bits of n + DP exponent bias */
|
||||
mulsd %xmm2, %xmm3 /* DP P2*z */
|
||||
shlq $46, %rdx /* DP 2^n */
|
||||
addsd L(DP_P1)(%rip), %xmm4 /* DP P3*z+P1 */
|
||||
addsd L(DP_P0)(%rip), %xmm3 /* DP P2*z+P0 */
|
||||
movd %rdx, %xmm1 /* DP 2^n */
|
||||
mulsd %xmm2, %xmm4 /* DP (P3*z+P1)*z */
|
||||
mulsd %xmm3, %xmm0 /* DP (P2*z+P0)*y */
|
||||
addsd %xmm4, %xmm0 /* DP P(y) */
|
||||
mulsd (%rsi,%rax,8), %xmm0 /* DP P(y)*T[j] */
|
||||
addsd (%rsi,%rax,8), %xmm0 /* DP T[j]*(P(y)+1) */
|
||||
mulsd %xmm1, %xmm0 /* DP result=2^n*(T[j]*(P(y)+1)) */
|
||||
cvtsd2ss %xmm0, %xmm0 /* convert result to single precision */
|
||||
ret
|
||||
END(__ieee754_expf)
|
||||
|
||||
.section .rodata, "a"
|
||||
.p2align 3
|
||||
L(DP_T): /* table of double precision values 2^(j/K) for j=[0..K-1] */
|
||||
.long 0x00000000, 0x3ff00000
|
||||
.long 0x3e778061, 0x3ff02c9a
|
||||
.long 0xd3158574, 0x3ff059b0
|
||||
.long 0x18759bc8, 0x3ff08745
|
||||
.long 0x6cf9890f, 0x3ff0b558
|
||||
.long 0x32d3d1a2, 0x3ff0e3ec
|
||||
.long 0xd0125b51, 0x3ff11301
|
||||
.long 0xaea92de0, 0x3ff1429a
|
||||
.long 0x3c7d517b, 0x3ff172b8
|
||||
.long 0xeb6fcb75, 0x3ff1a35b
|
||||
.long 0x3168b9aa, 0x3ff1d487
|
||||
.long 0x88628cd6, 0x3ff2063b
|
||||
.long 0x6e756238, 0x3ff2387a
|
||||
.long 0x65e27cdd, 0x3ff26b45
|
||||
.long 0xf51fdee1, 0x3ff29e9d
|
||||
.long 0xa6e4030b, 0x3ff2d285
|
||||
.long 0x0a31b715, 0x3ff306fe
|
||||
.long 0xb26416ff, 0x3ff33c08
|
||||
.long 0x373aa9cb, 0x3ff371a7
|
||||
.long 0x34e59ff7, 0x3ff3a7db
|
||||
.long 0x4c123422, 0x3ff3dea6
|
||||
.long 0x21f72e2a, 0x3ff4160a
|
||||
.long 0x6061892d, 0x3ff44e08
|
||||
.long 0xb5c13cd0, 0x3ff486a2
|
||||
.long 0xd5362a27, 0x3ff4bfda
|
||||
.long 0x769d2ca7, 0x3ff4f9b2
|
||||
.long 0x569d4f82, 0x3ff5342b
|
||||
.long 0x36b527da, 0x3ff56f47
|
||||
.long 0xdd485429, 0x3ff5ab07
|
||||
.long 0x15ad2148, 0x3ff5e76f
|
||||
.long 0xb03a5585, 0x3ff6247e
|
||||
.long 0x82552225, 0x3ff66238
|
||||
.long 0x667f3bcd, 0x3ff6a09e
|
||||
.long 0x3c651a2f, 0x3ff6dfb2
|
||||
.long 0xe8ec5f74, 0x3ff71f75
|
||||
.long 0x564267c9, 0x3ff75feb
|
||||
.long 0x73eb0187, 0x3ff7a114
|
||||
.long 0x36cf4e62, 0x3ff7e2f3
|
||||
.long 0x994cce13, 0x3ff82589
|
||||
.long 0x9b4492ed, 0x3ff868d9
|
||||
.long 0x422aa0db, 0x3ff8ace5
|
||||
.long 0x99157736, 0x3ff8f1ae
|
||||
.long 0xb0cdc5e5, 0x3ff93737
|
||||
.long 0x9fde4e50, 0x3ff97d82
|
||||
.long 0x82a3f090, 0x3ff9c491
|
||||
.long 0x7b5de565, 0x3ffa0c66
|
||||
.long 0xb23e255d, 0x3ffa5503
|
||||
.long 0x5579fdbf, 0x3ffa9e6b
|
||||
.long 0x995ad3ad, 0x3ffae89f
|
||||
.long 0xb84f15fb, 0x3ffb33a2
|
||||
.long 0xf2fb5e47, 0x3ffb7f76
|
||||
.long 0x904bc1d2, 0x3ffbcc1e
|
||||
.long 0xdd85529c, 0x3ffc199b
|
||||
.long 0x2e57d14b, 0x3ffc67f1
|
||||
.long 0xdcef9069, 0x3ffcb720
|
||||
.long 0x4a07897c, 0x3ffd072d
|
||||
.long 0xdcfba487, 0x3ffd5818
|
||||
.long 0x03db3285, 0x3ffda9e6
|
||||
.long 0x337b9b5f, 0x3ffdfc97
|
||||
.long 0xe78b3ff6, 0x3ffe502e
|
||||
.long 0xa2a490da, 0x3ffea4af
|
||||
.long 0xee615a27, 0x3ffefa1b
|
||||
.long 0x5b6e4540, 0x3fff5076
|
||||
.long 0x819e90d8, 0x3fffa7c1
|
||||
ASM_TYPE_DIRECTIVE(L(DP_T), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(DP_T))
|
||||
|
||||
.section .rodata.cst8,"aM",@progbits,8
|
||||
.p2align 3
|
||||
L(DP_KLN2): /* double precision K/log(2) */
|
||||
.long 0x652b82fe, 0x40571547
|
||||
ASM_TYPE_DIRECTIVE(L(DP_KLN2), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(DP_KLN2))
|
||||
|
||||
.p2align 3
|
||||
L(DP_NLN2K): /* double precision -log(2)/K */
|
||||
.long 0xfefa39ef, 0xbf862e42
|
||||
ASM_TYPE_DIRECTIVE(L(DP_NLN2K), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(DP_NLN2K))
|
||||
|
||||
.p2align 3
|
||||
L(DP_RS): /* double precision 2^23+2^22 */
|
||||
.long 0x00000000, 0x41680000
|
||||
ASM_TYPE_DIRECTIVE(L(DP_RS), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(DP_RS))
|
||||
|
||||
.p2align 3
|
||||
L(DP_P3): /* double precision polynomial coefficient P3 */
|
||||
.long 0xeb78fa85, 0x3fa56420
|
||||
ASM_TYPE_DIRECTIVE(L(DP_P3), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(DP_P3))
|
||||
|
||||
.p2align 3
|
||||
L(DP_P1): /* double precision polynomial coefficient P1 */
|
||||
.long 0x008d6118, 0x3fe00000
|
||||
ASM_TYPE_DIRECTIVE(L(DP_P1), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(DP_P1))
|
||||
|
||||
.p2align 3
|
||||
L(DP_P2): /* double precision polynomial coefficient P2 */
|
||||
.long 0xda752d4f, 0x3fc55550
|
||||
ASM_TYPE_DIRECTIVE(L(DP_P2), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(DP_P2))
|
||||
|
||||
.p2align 3
|
||||
L(DP_P0): /* double precision polynomial coefficient P0 */
|
||||
.long 0xffffe7c6, 0x3fefffff
|
||||
ASM_TYPE_DIRECTIVE(L(DP_P0), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(DP_P0))
|
||||
|
||||
.p2align 2
|
||||
L(SP_RANGE): /* single precision overflow/underflow bounds */
|
||||
.long 0x42b17217 /* if x>this bound, then result overflows */
|
||||
.long 0x42cff1b4 /* if x<this bound, then result underflows */
|
||||
ASM_TYPE_DIRECTIVE(L(SP_RANGE), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(SP_RANGE))
|
||||
|
||||
.p2align 2
|
||||
L(SP_INF_0):
|
||||
.long 0x7f800000 /* single precision Inf */
|
||||
.long 0 /* single precision zero */
|
||||
ASM_TYPE_DIRECTIVE(L(SP_INF_0), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(SP_INF_0))
|
||||
|
||||
.section .rodata.cst4,"aM",@progbits,4
|
||||
.p2align 2
|
||||
L(SP_RS): /* single precision 2^23+2^22 */
|
||||
.long 0x4b400000
|
||||
ASM_TYPE_DIRECTIVE(L(SP_RS), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(SP_RS))
|
||||
|
||||
.p2align 2
|
||||
L(SP_SMALL): /* single precision small value 2^(-100) */
|
||||
.long 0x0d800000
|
||||
ASM_TYPE_DIRECTIVE(L(SP_SMALL), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(SP_SMALL))
|
||||
|
||||
.p2align 2
|
||||
L(SP_LARGE): /* single precision large value 2^100 */
|
||||
.long 0x71800000
|
||||
ASM_TYPE_DIRECTIVE(L(SP_LARGE), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(SP_LARGE))
|
||||
|
||||
.p2align 2
|
||||
L(SP_ONE): /* single precision 1.0 */
|
||||
.long 0x3f800000
|
||||
ASM_TYPE_DIRECTIVE(L(SP_ONE), @object)
|
||||
ASM_SIZE_DIRECTIVE(L(SP_ONE))
|
||||
|
||||
strong_alias (__ieee754_expf, __expf_finite)
|
||||
Loading…
Reference in New Issue
Block a user