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author | Siddhesh Poyarekar <siddhesh@redhat.com> | 2013-03-26 19:28:50 +0530 |
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committer | Siddhesh Poyarekar <siddhesh@redhat.com> | 2013-03-26 19:28:50 +0530 |
commit | 6f2e90e78f151bab153c2b38492505ae2012db06 (patch) | |
tree | 03965f28878b90725ad89572ae61993bff4ebdfd /sysdeps/powerpc | |
parent | fce14d4e9c6e08ad8c825fe88d8cbdac5c739565 (diff) | |
download | glibc-6f2e90e78f151bab153c2b38492505ae2012db06.tar.gz glibc-6f2e90e78f151bab153c2b38492505ae2012db06.tar.xz glibc-6f2e90e78f151bab153c2b38492505ae2012db06.zip |
Make mantissa type of mp_no configurable
The mantissa of mp_no is intended to take only integral values. This is a relatively good choice for powerpc due to its 4 fpus, but not for other architectures, which suffer due to this choice. This change makes the default mantissa a long integer and allows powerpc to override it. Additionally, some operations have been optimized for integer manipulation, resulting in a significant improvement in performance.
Diffstat (limited to 'sysdeps/powerpc')
-rw-r--r-- | sysdeps/powerpc/power4/fpu/mpa-arch.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/sysdeps/powerpc/power4/fpu/mpa-arch.h b/sysdeps/powerpc/power4/fpu/mpa-arch.h new file mode 100644 index 0000000000..9007c9d0ca --- /dev/null +++ b/sysdeps/powerpc/power4/fpu/mpa-arch.h @@ -0,0 +1,56 @@ +/* Overridable constants and operations. + Copyright (C) 2013 Free Software Foundation, Inc. + + This program 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. + + This program 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 this program; if not, see <http://www.gnu.org/licenses/>. */ + +typedef double mantissa_t; +typedef double mantissa_store_t; + +#define TWOPOW(i) (0x1.0p##i) + +#define RADIX TWOPOW (24) /* 2^24 */ +#define CUTTER TWOPOW (76) /* 2^76 */ +#define RADIXI 0x1.0p-24 /* 2^-24 */ +#define TWO52 TWOPOW (52) /* 2^52 */ + +/* Divide D by RADIX and put the remainder in R. */ +#define DIV_RADIX(d,r) \ + ({ \ + double u = ((d) + CUTTER) - CUTTER; \ + if (u > (d)) \ + u -= RADIX; \ + r = (d) - u; \ + (d) = u * RADIXI; \ + }) + +/* Put the integer component of a double X in R and retain the fraction in + X. */ +#define INTEGER_OF(x, r) \ + ({ \ + double u = ((x) + TWO52) - TWO52; \ + if (u > (x)) \ + u -= ONE; \ + (r) = u; \ + (x) -= u; \ + }) + +/* Align IN down to a multiple of F, where F is a power of two. */ +#define ALIGN_DOWN_TO(in, f) \ + ({ \ + double factor = f * TWO52; \ + double u = (in + factor) - factor; \ + if (u > in) \ + u -= f; \ + u; \ + }) |