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author | David S. Miller <davem@davemloft.net> | 2012-02-27 20:36:30 -0800 |
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committer | David S. Miller <davem@davemloft.net> | 2012-02-27 20:36:30 -0800 |
commit | 1aff59a3f78e2eea23c5303cede967613bd13bfc (patch) | |
tree | 62e7b41ba1d53078cab0fbe80746af5a8726af71 /sysdeps/sparc/sparc64/fpu/s_floorf.S | |
parent | d6b5aa5879729713ffd27d38307e373bf60b0049 (diff) | |
download | glibc-1aff59a3f78e2eea23c5303cede967613bd13bfc.tar.gz glibc-1aff59a3f78e2eea23c5303cede967613bd13bfc.tar.xz glibc-1aff59a3f78e2eea23c5303cede967613bd13bfc.zip |
Optimized sparc floor{,f} routines.
* sysdeps/sparc/sparc32/sparcv9/fpu/s_floor.S: New file. * sysdeps/sparc/sparc32/sparcv9/fpu/s_floorf.S: New file. * sysdeps/sparc/sparc64/fpu/s_floor.S: New file. * sysdeps/sparc/sparc64/fpu/s_floorf.S: New file.
Diffstat (limited to 'sysdeps/sparc/sparc64/fpu/s_floorf.S')
-rw-r--r-- | sysdeps/sparc/sparc64/fpu/s_floorf.S | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/sysdeps/sparc/sparc64/fpu/s_floorf.S b/sysdeps/sparc/sparc64/fpu/s_floorf.S new file mode 100644 index 0000000000..711cbe4d1e --- /dev/null +++ b/sysdeps/sparc/sparc64/fpu/s_floorf.S @@ -0,0 +1,81 @@ +/* Float floor function, sparc64 version. + Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by David S. Miller <davem@davemloft.net>, 2012. + + 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 + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + + /* Since changing the rounding mode is extremely expensive, we + try to round up using a method that is rounding mode + agnostic. + + We add then subtract (or subtract than add if the initial + value was negative) 2**23 to the value, then subtract it + back out. + + This will clear out the fractional portion of the value. + One of two things will happen for non-whole initial values. + Either the rounding mode will round it up, or it will be + rounded down. If the value started out whole, it will be + equal after the addition and subtraction. This means we + can accurately detect with one test whether we need to add + another 1.0 to round it up properly. + + We pop constants into the FPU registers using the incoming + argument stack slots, since this avoid having to use any + PIC references. We also thus avoid having to allocate a + register window. + + VIS instructions are used to facilitate the formation of + easier constants, and the propagation of the sign bit. */ + +#define TWO_TWENTYTHREE 0x4b000000 /* 2**23 */ +#define ONE_DOT_ZERO 0x3f800000 /* 1.0 */ + +#define ZERO %f10 /* 0.0 */ +#define SIGN_BIT %f12 /* -0.0 */ + +ENTRY (__floorf) + sethi %hi(TWO_TWENTYTHREE), %o2 + sethi %hi(ONE_DOT_ZERO), %o3 + fzeros ZERO + + fnegs ZERO, SIGN_BIT + + st %o2, [%sp + STACK_BIAS + 128] + fabss %f1, %f14 + + ld [%sp + STACK_BIAS + 128], %f16 + fcmps %fcc3, %f14, %f16 + + fmovsuge %fcc3, ZERO, %f16 + fands %f1, SIGN_BIT, SIGN_BIT + + fors %f16, SIGN_BIT, %f16 + fadds %f1, %f16, %f5 + fsubs %f5, %f16, %f5 + fcmps %fcc2, %f5, %f1 + st %o3, [%sp + STACK_BIAS + 128] + + ld [%sp + STACK_BIAS + 128], %f9 + fmovsule %fcc2, ZERO, %f9 + fsubs %f5, %f9, %f0 + fabss %f0, %f0 + retl + fors %f0, SIGN_BIT, %f0 +END (__floorf) +weak_alias (__floorf, floorf) |