-2010-05-05 Richard Henderson <rth@redhat.com>
+2010-09-23 Richard Henderson <rth@redhat.com>
+
+ [BZ #12019]
+ * sysdeps/alpha/alphaev6/memchr.S: Remove.
+ * sysdeps/alpha/memchr.S: Remove.
+ * sysdeps/alpha/memchr.c: New.
+
+2010-09-23 Richard Henderson <rth@redhat.com>
[BZ #1864]
* sysdeps/unix/sysv/linux/alpha/fstatfs64.c: New.
+++ /dev/null
-/* Copyright (C) 2000, 2003 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by David Mosberger (davidm@cs.arizona.edu).
- EV6 optimized by Rick Gorton <rick.gorton@alpha-processor.com>.
-
- 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>
-
- .arch ev6
- .set noreorder
- .set noat
-
-ENTRY(__memchr)
-#ifdef PROF
- ldgp gp, 0(pv)
- lda AT, _mcount
- jsr AT, (AT), _mcount
- .prologue 1
-#else
- .prologue 0
-#endif
-
- # Hack -- if someone passes in (size_t)-1, hoping to just
- # search til the end of the address space, we will overflow
- # below when we find the address of the last byte. Given
- # that we will never have a 56-bit address space, cropping
- # the length is the easiest way to avoid trouble.
- zap $18, 0x80, $5 # U : Bound length
- beq $18, $not_found # U :
- ldq_u $1, 0($16) # L : load first quadword Latency=3
- and $17, 0xff, $17 # E : L L U U : 00000000000000ch
-
- insbl $17, 1, $2 # U : 000000000000ch00
- cmpult $18, 9, $4 # E : small (< 1 quad) string?
- or $2, $17, $17 # E : 000000000000chch
- lda $3, -1($31) # E : U L L U
-
- sll $17, 16, $2 # U : 00000000chch0000
- addq $16, $5, $5 # E : Max search address
- or $2, $17, $17 # E : 00000000chchchch
- sll $17, 32, $2 # U : U L L U : chchchch00000000
-
- or $2, $17, $17 # E : chchchchchchchch
- extql $1, $16, $7 # U : $7 is upper bits
- beq $4, $first_quad # U :
- ldq_u $6, -1($5) # L : L U U L : eight or less bytes to search Latency=3
-
- extqh $6, $16, $6 # U : 2 cycle stall for $6
- mov $16, $0 # E :
- nop # E :
- or $7, $6, $1 # E : L U L U $1 = quadword starting at $16
-
- # Deal with the case where at most 8 bytes remain to be searched
- # in $1. E.g.:
- # $18 = 6
- # $1 = ????c6c5c4c3c2c1
-$last_quad:
- negq $18, $6 # E :
- xor $17, $1, $1 # E :
- srl $3, $6, $6 # U : $6 = mask of $18 bits set
- cmpbge $31, $1, $2 # E : L U L U
-
- nop
- nop
- and $2, $6, $2 # E :
- beq $2, $not_found # U : U L U L
-
-$found_it:
-#if defined(__alpha_fix__) && defined(__alpha_cix__)
- /*
- * Since we are guaranteed to have set one of the bits, we don't
- * have to worry about coming back with a 0x40 out of cttz...
- */
- cttz $2, $3 # U0 :
- addq $0, $3, $0 # E : All done
- nop # E :
- ret # L0 : L U L U
-#else
- /*
- * Slow and clunky. It can probably be improved.
- * An exercise left for others.
- */
- negq $2, $3 # E :
- and $2, $3, $2 # E :
- and $2, 0x0f, $1 # E :
- addq $0, 4, $3 # E :
-
- cmoveq $1, $3, $0 # E : Latency 2, extra map cycle
- nop # E : keep with cmov
- and $2, 0x33, $1 # E :
- addq $0, 2, $3 # E : U L U L : 2 cycle stall on $0
-
- cmoveq $1, $3, $0 # E : Latency 2, extra map cycle
- nop # E : keep with cmov
- and $2, 0x55, $1 # E :
- addq $0, 1, $3 # E : U L U L : 2 cycle stall on $0
-
- cmoveq $1, $3, $0 # E : Latency 2, extra map cycle
- nop
- nop
- ret # L0 : L U L U
-#endif
-
- # Deal with the case where $18 > 8 bytes remain to be
- # searched. $16 may not be aligned.
- .align 4
-$first_quad:
- andnot $16, 0x7, $0 # E :
- insqh $3, $16, $2 # U : $2 = 0000ffffffffffff ($16<0:2> ff)
- xor $1, $17, $1 # E :
- or $1, $2, $1 # E : U L U L $1 = ====ffffffffffff
-
- cmpbge $31, $1, $2 # E :
- bne $2, $found_it # U :
- # At least one byte left to process.
- ldq $31, 8($0) # L :
- subq $5, 1, $18 # E : U L U L
-
- addq $0, 8, $0 # E :
- # Make $18 point to last quad to be accessed (the
- # last quad may or may not be partial).
- andnot $18, 0x7, $18 # E :
- cmpult $0, $18, $2 # E :
- beq $2, $final # U : U L U L
-
- # At least two quads remain to be accessed.
-
- subq $18, $0, $4 # E : $4 <- nr quads to be processed
- and $4, 8, $4 # E : odd number of quads?
- bne $4, $odd_quad_count # U :
- # At least three quads remain to be accessed
- nop # E : L U L U : move prefetched value to correct reg
-
- .align 4
-$unrolled_loop:
- ldq $1, 0($0) # L : load quad
- xor $17, $1, $2 # E :
- ldq $31, 8($0) # L : prefetch next quad
- cmpbge $31, $2, $2 # E : U L U L
-
- bne $2, $found_it # U :
- addq $0, 8, $0 # E :
- nop # E :
- nop # E :
-
-$odd_quad_count:
- ldq $1, 0($0) # L : load quad
- xor $17, $1, $2 # E :
- ldq $31, 8($0) # L : prefetch $4
- cmpbge $31, $2, $2 # E :
-
- addq $0, 8, $6 # E :
- bne $2, $found_it # U :
- cmpult $6, $18, $6 # E :
- addq $0, 8, $0 # E :
-
- bne $6, $unrolled_loop # U :
- nop # E :
- nop # E :
- nop # E :
-
-$final: ldq $1, 0($0) # L : load last quad
- subq $5, $0, $18 # E : $18 <- number of bytes left to do
- nop # E :
- bne $18, $last_quad # U :
-
-$not_found:
- mov $31, $0 # E :
- nop # E :
- nop # E :
- ret # L0 :
-
- END(__memchr)
-
-weak_alias (__memchr, memchr)
-#if !__BOUNDED_POINTERS__
-weak_alias (__memchr, __ubp_memchr)
-#endif
-libc_hidden_builtin_def (memchr)
+++ /dev/null
-/* Copyright (C) 1996, 2000, 2003 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by David Mosberger (davidm@cs.arizona.edu).
-
- 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. */
-
-/* Finds characters in a memory area. Optimized for the Alpha:
-
- - memory accessed as aligned quadwords only
- - uses cmpbge to compare 8 bytes in parallel
- - does binary search to find 0 byte in last
- quadword (HAKMEM needed 12 instructions to
- do this instead of the 9 instructions that
- binary search needs).
-
-For correctness consider that:
-
- - only minimum number of quadwords may be accessed
- - the third argument is an unsigned long
-*/
-
-#include <sysdep.h>
-
- .set noreorder
- .set noat
-
-ENTRY(__memchr)
-#ifdef PROF
- ldgp gp, 0(pv)
- lda AT, _mcount
- jsr AT, (AT), _mcount
- .prologue 1
-#else
- .prologue 0
-#endif
-
- # Hack -- if someone passes in (size_t)-1, hoping to just
- # search til the end of the address space, we will overflow
- # below when we find the address of the last byte. Given
- # that we will never have a 56-bit address space, cropping
- # the length is the easiest way to avoid trouble.
- zap a2, 0x80, t4 #-e0 :
-
- beq a2, $not_found # .. e1 :
- ldq_u t0, 0(a0) # e1 : load first quadword
- insbl a1, 1, t1 # .. e0 : t1 = 000000000000ch00
- and a1, 0xff, a1 #-e0 : a1 = 00000000000000ch
- cmpult a2, 9, t3 # .. e1 :
- or t1, a1, a1 # e0 : a1 = 000000000000chch
- lda t2, -1(zero) # .. e1 :
- sll a1, 16, t1 #-e0 : t1 = 00000000chch0000
- addq a0, t4, t4 # .. e1 :
- or t1, a1, a1 # e1 : a1 = 00000000chchchch
- unop # :
- sll a1, 32, t1 #-e0 : t1 = chchchch00000000
- or t1, a1, a1 # e1 : a1 = chchchchchchchch
- extql t0, a0, t6 # e0 :
- beq t3, $first_quad # .. e1 :
-
- ldq_u t5, -1(t4) #-e1 : eight or less bytes to search
- extqh t5, a0, t5 # .. e0 :
- mov a0, v0 # e0 :
- or t6, t5, t0 # .. e1 : t0 = quadword starting at a0
-
- # Deal with the case where at most 8 bytes remain to be searched
- # in t0. E.g.:
- # a2 = 6
- # t0 = ????c6c5c4c3c2c1
-$last_quad:
- negq a2, t5 #-e0 :
- xor a1, t0, t0 # .. e1 :
- srl t2, t5, t5 # e0 : t5 = mask of a2 bits set
- cmpbge zero, t0, t1 # .. e1 :
- and t1, t5, t1 #-e0 :
- beq t1, $not_found # .. e1 :
-
-$found_it:
- # Now, determine which byte matched:
- negq t1, t2 # e0 :
- and t1, t2, t1 # e1 :
-
- and t1, 0x0f, t0 #-e0 :
- addq v0, 4, t2 # .. e1 :
- cmoveq t0, t2, v0 # e0 :
-
- addq v0, 2, t2 # .. e1 :
- and t1, 0x33, t0 #-e0 :
- cmoveq t0, t2, v0 # .. e1 :
-
- and t1, 0x55, t0 # e0 :
- addq v0, 1, t2 # .. e1 :
- cmoveq t0, t2, v0 #-e0 :
-
-$done: ret # .. e1 :
-
- # Deal with the case where a2 > 8 bytes remain to be
- # searched. a0 may not be aligned.
- .align 4
-$first_quad:
- andnot a0, 0x7, v0 #-e1 :
- insqh t2, a0, t1 # .. e0 : t1 = 0000ffffffffffff (a0<0:2> ff)
- xor t0, a1, t0 # e0 :
- or t0, t1, t0 # e1 : t0 = ====ffffffffffff
- cmpbge zero, t0, t1 #-e0 :
- bne t1, $found_it # .. e1 :
-
- # At least one byte left to process.
-
- ldq zero, 8(v0) # e0 : prefetch next quad
- subq t4, 1, a2 # .. e1 :
- addq v0, 8, v0 #-e0 :
-
- # Make a2 point to last quad to be accessed (the
- # last quad may or may not be partial).
-
- andnot a2, 0x7, a2 # .. e1 :
- cmpult v0, a2, t1 # e0 :
- beq t1, $final # .. e1 :
-
- # At least two quads remain to be accessed.
-
- subq a2, v0, t3 #-e0 : t3 <- nr quads to be processed
- and t3, 8, t3 # e1 : odd number of quads?
- bne t3, $odd_quad_count # e1 :
-
- # At least three quads remain to be accessed
-
- .align 4
-$unrolled_loop:
- ldq t0, 0(v0) # e0 : load quad
- xor a1, t0, t1 # .. e1 :
- ldq zero, 8(v0) # e0 : prefetch next quad
- cmpbge zero, t1, t1 # .. e1:
- bne t1, $found_it # e0 :
-
- addq v0, 8, v0 # e1 :
-$odd_quad_count:
- ldq t0, 0(v0) # e0 : load quad
- xor a1, t0, t1 # .. e1 :
- ldq zero, 8(v0) # e0 : prefetch next quad
- cmpbge zero, t1, t1 # .. e1 :
- addq v0, 8, t5 #-e0 :
- bne t1, $found_it # .. e1 :
-
- cmpult t5, a2, t5 # e0 :
- addq v0, 8, v0 # .. e1 :
- bne t5, $unrolled_loop #-e1 :
-
-$final: ldq t0, 0(v0) # e0 : load last quad
- subq t4, v0, a2 # .. e1 : a2 <- number of bytes left to do
- bne a2, $last_quad # e1 :
-
-$not_found:
- mov zero, v0 #-e0 :
- ret # .. e1 :
-
- END(__memchr)
-
-weak_alias (__memchr, memchr)
-#if !__BOUNDED_POINTERS__
-weak_alias (__memchr, __ubp_memchr)
-#endif
-libc_hidden_builtin_def (memchr)
--- /dev/null
+/* Copyright (C) 2010 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <string.h>
+
+typedef unsigned long word;
+
+static inline word
+ldq_u(const void *s)
+{
+ return *(const word *)((word)s & -8);
+}
+
+#define unlikely(X) __builtin_expect ((X), 0)
+#define prefetch(X) __builtin_prefetch ((void *)(X), 0)
+
+#define cmpbeq0(X) __builtin_alpha_cmpbge(0, (X))
+#define find(X, Y) cmpbeq0 ((X) ^ (Y))
+
+/* Search no more than N bytes of S for C. */
+
+void *
+__memchr (const void *s, int xc, size_t n)
+{
+ const word *s_align;
+ word t, current, found, mask, offset;
+
+ if (unlikely (n == 0))
+ return 0;
+
+ current = ldq_u (s);
+
+ /* Replicate low byte of XC into all bytes of C. */
+ t = xc & 0xff; /* 0000000c */
+ t = (t << 8) | t; /* 000000cc */
+ t = (t << 16) | t; /* 0000cccc */
+ const word c = (t << 32) | t; /* cccccccc */
+
+ /* Align the source, and decrement the count by the number
+ of bytes searched in the first word. */
+ s_align = (const word *)(s & -8);
+ n += (s & 7);
+
+ /* Deal with misalignment in the first word for the comparison. */
+ mask = (1ul << (s & 7)) - 1;
+
+ /* If the entire string fits within one word, we may need masking
+ at both the front and the back of the string. */
+ if (unlikely (n <= 8))
+ {
+ mask |= -1ul << n;
+ goto last_quad;
+ }
+
+ found = find (current, c) & ~mask;
+ if (unlikely (found))
+ goto found_it;
+
+ s_align++;
+ n -= 8;
+
+ /* If the block is sufficiently large, align to cacheline and prefetch. */
+ if (unlikely (n >= 256))
+ {
+ /* Prefetch 3 cache lines beyond the one we're working on. */
+ prefetch (s_align + 8);
+ prefetch (s_align + 16);
+ prefetch (s_align + 24);
+
+ while ((word)s_align & 63)
+ {
+ current = *s_align;
+ found = find (current, c);
+ if (found)
+ goto found_it;
+ s_align++;
+ n -= 8;
+ }
+
+ /* Within each cacheline, advance the load for the next word
+ before the test for the previous word is complete. This
+ allows us to hide the 3 cycle L1 cache load latency. We
+ only perform this advance load within a cacheline to prevent
+ reading across page boundary. */
+#define CACHELINE_LOOP \
+ do { \
+ word i, next = s_align[0]; \
+ for (i = 0; i < 7; ++i) \
+ { \
+ current = next; \
+ next = s_align[1]; \
+ found = find (current, c); \
+ if (unlikely (found)) \
+ goto found_it; \
+ s_align++; \
+ } \
+ current = next; \
+ found = find (current, c); \
+ if (unlikely (found)) \
+ goto found_it; \
+ s_align++; \
+ n -= 64; \
+ } while (0)
+
+ /* While there's still lots more data to potentially be read,
+ continue issuing prefetches for the 4th cacheline out. */
+ while (n >= 256)
+ {
+ prefetch (s_align + 24);
+ CACHELINE_LOOP;
+ }
+
+ /* Up to 3 cache lines remaining. Continue issuing advanced
+ loads, but stop prefetching. */
+ while (n >= 64)
+ CACHELINE_LOOP;
+
+ /* We may have exhausted the buffer. */
+ if (n == 0)
+ return NULL;
+ }
+
+ /* Quadword aligned loop. */
+ current = *s_align;
+ while (n > 8)
+ {
+ found = find (current, c);
+ if (unlikely (found))
+ goto found_it;
+ current = *++s_align;
+ n -= 8;
+ }
+
+ /* The last word may need masking at the tail of the compare. */
+ mask = -1ul << n;
+ last_quad:
+ found = find (current, c) & ~mask;
+ if (found == 0)
+ return NULL;
+
+ found_it:
+#ifdef __alpha_cix__
+ offset = __builtin_alpha_cttz (found);
+#else
+ /* Extract LSB. */
+ found &= -found;
+
+ /* Binary search for the LSB. */
+ offset = (found & 0x0f ? 0 : 4);
+ offset += (found & 0x33 ? 0 : 2);
+ offset += (found & 0x55 ? 0 : 1);
+#endif
+
+ return (void *)((word)s_align + offset);
+}
+
+#ifdef weak_alias
+weak_alias (__memchr, BP_SYM (memchr))
+#endif
+libc_hidden_builtin_def (memchr)
projects / platform / upstream / glibc.git / commitdiff