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author | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
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committer | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
commit | 5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch) | |
tree | 4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/sysdeps/alpha/alphaev67/strchr.S | |
parent | 199fc19d3aaaf57944ef036e15904febe877fc93 (diff) | |
download | glibc-zack/build-layout-experiment.tar.gz glibc-zack/build-layout-experiment.tar.xz glibc-zack/build-layout-experiment.zip |
Prepare for radical source tree reorganization. zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control).
Diffstat (limited to 'REORG.TODO/sysdeps/alpha/alphaev67/strchr.S')
-rw-r--r-- | REORG.TODO/sysdeps/alpha/alphaev67/strchr.S | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/alpha/alphaev67/strchr.S b/REORG.TODO/sysdeps/alpha/alphaev67/strchr.S new file mode 100644 index 0000000000..ac1886eb55 --- /dev/null +++ b/REORG.TODO/sysdeps/alpha/alphaev67/strchr.S @@ -0,0 +1,100 @@ +/* Copyright (C) 2000-2017 Free Software Foundation, Inc. + Contributed by Richard Henderson <rth@tamu.edu>, 1996. + EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>. + 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 + <http://www.gnu.org/licenses/>. */ + +/* Return the address of a given character within a null-terminated + string, or null if it is not found. */ + +#include <sysdep.h> + + .arch ev6 + .set noreorder + .set noat + +ENTRY(strchr) +#ifdef PROF + ldgp gp, 0(pv) + lda AT, _mcount + jsr AT, (AT), _mcount + .prologue 1 +#else + .prologue 0 +#endif + + ldq_u t0, 0(a0) # L : load first quadword Latency=3 + and a1, 0xff, t3 # E : 00000000000000ch + insbl a1, 1, t5 # U : 000000000000ch00 + insbl a1, 7, a2 # U : ch00000000000000 + + insbl t3, 6, a3 # U : 00ch000000000000 + or t5, t3, a1 # E : 000000000000chch + andnot a0, 7, v0 # E : align our loop pointer + lda t4, -1 # E : build garbage mask + + mskqh t4, a0, t4 # U : only want relevant part of first quad + or a2, a3, a2 # E : chch000000000000 + inswl a1, 2, t5 # E : 00000000chch0000 + inswl a1, 4, a3 # E : 0000chch00000000 + + or a1, a2, a1 # E : chch00000000chch + or a3, t5, t5 # E : 0000chchchch0000 + cmpbge zero, t0, t2 # E : bits set iff byte == zero + cmpbge zero, t4, t4 # E : bits set iff byte is garbage + + /* This quad is _very_ serialized. Lots of stalling happens */ + or t5, a1, a1 # E : chchchchchchchch + xor t0, a1, t1 # E : make bytes == c zero + cmpbge zero, t1, t3 # E : bits set iff byte == c + or t2, t3, t0 # E : bits set iff char match or zero match + + andnot t0, t4, t0 # E : clear garbage bits + cttz t0, a2 # U0 : speculative (in case we get a match) + nop # E : + bne t0, $found # U : + + /* + * Yuk. This loop is going to stall like crazy waiting for the + * data to be loaded. Not much can be done about it unless it's + * unrolled multiple times, which is generally unsafe. + */ +$loop: + ldq t0, 8(v0) # L : Latency=3 + addq v0, 8, v0 # E : + xor t0, a1, t1 # E : + cmpbge zero, t0, t2 # E : bits set iff byte == 0 + + cmpbge zero, t1, t3 # E : bits set iff byte == c + or t2, t3, t0 # E : + cttz t3, a2 # U0 : speculative (in case we get a match) + beq t0, $loop # U : + +$found: + negq t0, t1 # E : clear all but least set bit + and t0, t1, t0 # E : + and t0, t3, t1 # E : bit set iff byte was the char + addq v0, a2, v0 # E : Add in the bit number from above + + cmoveq t1, $31, v0 # E : Two mapping slots, latency = 2 + nop + nop + ret # L0 : + + END(strchr) + +weak_alias (strchr, index) +libc_hidden_builtin_def (strchr) |