From 777b1eea9df942aebc5ba38566111e667ddaaf91 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Tue, 15 May 2012 10:32:28 -0500 Subject: [PATCH] PowerPC - logb[f|l] optimization for POWER7 This patch provides optimized logb (1.2x on PPC32 and 2.5x on PPC64), logbf (1.1x on PPC32 and 2.2x on PPC64), and logbl (1.3x on PPC32 and 50% on PPC64) for the POWER7 processor. --- ChangeLog | 15 ++++++ sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c | 75 ++++++++++++++++++++++++++ sysdeps/powerpc/powerpc32/power7/fpu/s_logbf.c | 60 +++++++++++++++++++++ sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c | 72 +++++++++++++++++++++++++ sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c | 1 + sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c | 1 + sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c | 1 + 7 files changed, 225 insertions(+) create mode 100644 sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c create mode 100644 sysdeps/powerpc/powerpc32/power7/fpu/s_logbf.c create mode 100644 sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c create mode 100644 sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c create mode 100644 sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c create mode 100644 sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c diff --git a/ChangeLog b/ChangeLog index 51288eb675..7a1c154993 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,18 @@ +2012-05-15 Adhemerval Zanella + + * sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c: New file. Optimized + logb for POWER7. + * sysdeps/powerpc/powerpc32/power7/fpu/s_logbf.c: New file. Optimized + logbf for POWER7. + * sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c: New file. Optimized + logbl for POWER7. + * sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c: New file. Use + powerpc32/power7/fpu/s_logb.c via #include. + * sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c: New file. Use + powerpc32/power7/fpu/s_logbf.c via #include. + * sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c: New file. Use + powerpc32/power7/fpu/s_logbl.c via #include. + 2012-05-15 Joseph Myers * README.libm: Remove file. diff --git a/sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c b/sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c new file mode 100644 index 0000000000..71ee148149 --- /dev/null +++ b/sysdeps/powerpc/powerpc32/power7/fpu/s_logb.c @@ -0,0 +1,75 @@ +/* logb(). PowerPC/POWER7 version. + Copyright (C) 2012 Free Software Foundation, Inc. + 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, see + . */ + +#include "math_private.h" + +/* This implementation avoids FP to INT conversions by using VSX + bitwise instructions over FP values. */ + +static const double two1div52 = 2.220446049250313e-16; /* 1/2**52 */ +static const double two10m1 = -1023.0; /* 2**10 -1 */ + +/* FP mask to extract the exponent. */ +static const union { + unsigned long long mask; + double d; +} mask = { 0x7ff0000000000000ULL }; + +double +__logb (double x) +{ + double ret; + + if (__builtin_expect (x == 0.0, 0)) + /* Raise FE_DIVBYZERO and return -HUGE_VAL[LF]. */ + return -1.0 / __builtin_fabs (x); + + /* ret = x & 0x7ff0000000000000; */ + asm ( + "xxland %x0,%x1,%x2\n" + "fcfid %0,%0" + : "=f" (ret) + : "f" (x), "f" (mask.d)); + /* ret = (ret >> 52) - 1023.0; */ + ret = (ret * two1div52) + two10m1; + if (__builtin_expect (ret > -two10m1, 0)) + /* Multiplication is used to set logb (+-INF) = INF. */ + return (x * x); + else if (__builtin_expect (ret == two10m1, 0)) + { + /* POSIX specifies that denormal numbers are treated as + though they were normalized. */ + int32_t lx, ix; + int m1, m2, ma; + + EXTRACT_WORDS (ix , lx, x); + m1 = (ix == 0) ? 0 : __builtin_clz (ix); + m2 = (lx == 0) ? 0 : __builtin_clz (lx); + ma = (m1 == 0) ? m2 + 32 : m1; + return -1022.0 + (double)(11 - ma); + } + /* Test to avoid logb_downward (0.0) == -0.0. */ + return ret == -0.0 ? 0.0 : ret; +} + +weak_alias (__logb, logb) + +#ifdef NO_LONG_DOUBLE +strong_alias (__logb, __logbl) +weak_alias (__logb, logbl) +#endif diff --git a/sysdeps/powerpc/powerpc32/power7/fpu/s_logbf.c b/sysdeps/powerpc/powerpc32/power7/fpu/s_logbf.c new file mode 100644 index 0000000000..aa8499a14f --- /dev/null +++ b/sysdeps/powerpc/powerpc32/power7/fpu/s_logbf.c @@ -0,0 +1,60 @@ +/* logbf(). PowerPC/POWER7 version. + Copyright (C) 2012 Free Software Foundation, Inc. + 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, see + . */ + +#include "math_private.h" + +/* This implementation avoids FP to INT conversions by using VSX + bitwise instructions over FP values. */ + +static const double two1div52 = 2.220446049250313e-16; /* 1/2**52 */ +static const double two10m1 = -1023.0; /* -2**10 + 1 */ +static const double two7m1 = -127.0; /* -2**7 + 1 */ + +/* FP mask to extract the exponent. */ +static const union { + unsigned long long mask; + double d; +} mask = { 0x7ff0000000000000ULL }; + +float +__logbf (float x) +{ + /* VSX operation are all done internally as double. */ + double ret; + + if (__builtin_expect (x == 0.0, 0)) + /* Raise FE_DIVBYZERO and return -HUGE_VAL[LF]. */ + return -1.0 / __builtin_fabsf (x); + + /* ret = x & 0x7f800000; */ + asm ( + "xxland %x0,%x1,%x2\n" + "fcfid %0,%0" + : "=f"(ret) + : "f" (x), "f" (mask.d)); + /* ret = (ret >> 52) - 1023.0, since ret is double. */ + ret = (ret * two1div52) + two10m1; + if (__builtin_expect (ret > -two7m1, 0)) + /* Multiplication is used to set logb (+-INF) = INF. */ + return (x * x); + /* Since operations are done with double we don't need + additional tests for subnormal numbers. + The test is to avoid logb_downward (0.0) == -0.0. */ + return ret == -0.0 ? 0.0 : ret; +} +weak_alias (__logbf, logbf) diff --git a/sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c b/sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c new file mode 100644 index 0000000000..03942ca53d --- /dev/null +++ b/sysdeps/powerpc/powerpc32/power7/fpu/s_logbl.c @@ -0,0 +1,72 @@ +/* logbl(). PowerPC/POWER7 version. + Copyright (C) 2012 Free Software Foundation, Inc. + 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, see + . */ + +#include +#include +#include + +/* This implementation avoids FP to INT conversions by using VSX + bitwise instructions over FP values. */ + +static const double two1div52 = 2.220446049250313e-16; /* 1/2**52 */ +static const double two10m1 = -1023.0; /* 2**10 -1 */ + +/* FP mask to extract the exponent. */ +static const union { + unsigned long long mask; + double d; +} mask = { 0x7ff0000000000000ULL }; + +long double +__logbl (long double x) +{ + double xh, xl; + double ret; + + if (__builtin_expect (x == 0.0L, 0)) + /* Raise FE_DIVBYZERO and return -HUGE_VAL[LF]. */ + return -1.0L / __builtin_fabsl (x); + + ldbl_unpack (x, &xh, &xl); + /* ret = x & 0x7ff0000000000000; */ + asm ( + "xxland %x0,%x1,%x2\n" + "fcfid %0,%0" + : "=f" (ret) + : "f" (xh), "f" (mask.d)); + /* ret = (ret >> 52) - 1023.0; */ + ret = (ret * two1div52) + two10m1; + if (__builtin_expect (ret > -two10m1, 0)) + /* Multiplication is used to set logb (+-INF) = INF. */ + return (xh * xh); + else if (__builtin_expect (ret == two10m1, 0)) + { + int64_t lx, hx; + int m1, m2, ma; + + GET_LDOUBLE_WORDS64 (hx, lx, x); + m1 = (hx == 0) ? 0 : __builtin_clzll (hx); + m2 = (lx == 0) ? 0 : __builtin_clzll (lx); + ma = (m1 == 0) ? m2 + 64 : m1; + return -1022.0 + (double)(11 - ma); + } + /* Test to avoid logb_downward (0.0) == -0.0. */ + return ret == -0.0 ? 0.0 : ret; +} + +long_double_symbol (libm, __logbl, logbl); diff --git a/sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c b/sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c new file mode 100644 index 0000000000..ff3a9e0c77 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/power7/fpu/s_logb.c @@ -0,0 +1 @@ +#include diff --git a/sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c b/sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c new file mode 100644 index 0000000000..e79a28f775 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/power7/fpu/s_logbf.c @@ -0,0 +1 @@ +#include diff --git a/sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c b/sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c new file mode 100644 index 0000000000..463e411b4e --- /dev/null +++ b/sysdeps/powerpc/powerpc64/power7/fpu/s_logbl.c @@ -0,0 +1 @@ +#include -- 2.11.4.GIT