[PATCH] optimized SPU specific code for str[n]cpy and str[n]cat
Jeff Johnston
jjohnstn@redhat.com
Tue Feb 12 07:18:00 GMT 2008
Patch applied.
-- Jeff J.
Patrick Mansfield wrote:
> Jeff - can you please apply?
>
> Optimized SPU specific code for str[n]cpy and str[n]cat.
>
> These decrease (for simple performance tests) execution times compared to
> current SPU code for these functions by 20 to 50 percent.
>
> Generally, code size increases, with a worst case increase of 680 bytes.
>
> newlib/ChangeLog:
>
> 2008-02-11 Patrick Mansfield <patmans@us.ibm.com>
>
> * libc/machine/spu/straddr.h: New file, supplies _straddr.
> * libc/machine/spu/strcat.c: Use _straddr and _strcpy.
> * libc/machine/spu/strcpy.c: Use _strcpy.
> * libc/machine/spu/strcpy.h: Supply _strcpy for optimized SPU
> str[n]cpy and str[n]cat.
> * libc/machine/spu/strncat.c: Use _straddr and _strcpy.
> * libc/machine/spu/strncpy.c: Use _strcpy.
>
> Index: quilt/newlib/libc/machine/spu/strcat.c
> ===================================================================
> --- quilt.orig/newlib/libc/machine/spu/strcat.c
> +++ quilt/newlib/libc/machine/spu/strcat.c
> @@ -1,9 +1,6 @@
> /*
> - (C) Copyright 2001,2006,
> + (C) Copyright 2008
> International Business Machines Corporation,
> - Sony Computer Entertainment, Incorporated,
> - Toshiba Corporation,
> -
> All rights reserved.
>
> Redistribution and use in source and binary forms, with or without
> @@ -30,26 +27,19 @@
> ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
> POSSIBILITY OF SUCH DAMAGE.
> */
> -#include <spu_intrinsics.h>
> +
> #include <stddef.h>
> #include <string.h>
> +#include "straddr.h"
> +#include "strcpy.h"
>
> -/* Appends the string pointed to by src (up to and including the /0
> - * character) to the array pointed to by dest (overwriting the
> +/*
> + * Appends the string pointed to by src (up to and including the /0
> + * character) to the array pointed to by dest overwriting the
> * /0 character at the end of dest. The strings may not overlap and
> * the dest string must have enough space for the result.
> */
> -
> char *strcat(char * __restrict__ dest, const char * __restrict__ src)
> {
> - size_t d_len, s_len;
> -
> - /* Determine the length of the src and dest input arrays.
> - */
> - d_len = strlen(dest);
> - s_len = strlen(src);
> -
> - (void)memcpy((void *)(dest+d_len), (const void *)src, s_len + 1);
> -
> - return ((char *)dest);
> + return _strncpy(_straddr(dest), src, 0, 0, 0);
> }
> Index: quilt/newlib/libc/machine/spu/strcpy.h
> ===================================================================
> --- /dev/null
> +++ quilt/newlib/libc/machine/spu/strcpy.h
> @@ -0,0 +1,180 @@
> +/*
> + (C) Copyright 2008
> + International Business Machines Corporation,
> + All rights reserved.
> +
> + Redistribution and use in source and binary forms, with or without
> + modification, are permitted provided that the following conditions are met:
> +
> + * Redistributions of source code must retain the above copyright notice,
> + this list of conditions and the following disclaimer.
> + * Redistributions in binary form must reproduce the above copyright
> + notice, this list of conditions and the following disclaimer in the
> + documentation and/or other materials provided with the distribution.
> + * Neither the names of the copyright holders nor the names of their
> + contributors may be used to endorse or promote products derived from
> + this software without specific prior written permission.
> +
> + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
> + IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
> + TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
> + PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
> + OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
> + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
> + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
> + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
> + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
> + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
> + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> +*/
> +
> +#include <spu_intrinsics.h>
> +#include "vec_literal.h"
> +
> +/*
> + * Supply an inline _strncpy for strcpy/cat and strncpy/cat. Relies on
> + * checklen and lastzero code being optimized out when they are constant
> + * zero values.
> + */
> +static inline void * _strncpy(char * __restrict__ dest, const char *
> + __restrict__ src, size_t maxlen, int
> + checklen, int lastzero)
> +{
> + int adjust, offset, soffset, doffset, shift;
> + vec_uchar16 *vsrc, *vdest;
> + vec_uchar16 sdata1, sdata2, sdata, shuffle;
> + vec_uchar16 mask1, maskzero, cmp0;
> + vec_uint4 nonzeroes, gathered_cmp, vtmp, vtmp2;
> + vec_uint4 curlen; /* assumes size_t is 4 bytes */
> + const vec_uint4 val31 = { 31, 31, 31, 31 };
> + const vec_uint4 val_0123 = { 0x00010203, 0x04050607, 0x08090A0B, 0x0C0D0E0F };
> + const vec_uchar16 all_ones = { 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff,
> + 0xff,0xff,0xff,0xff, 0xff,0xff,0xff,0xff };
> +
> + vsrc = (vec_uchar16 *) src;
> + vdest = (vec_uchar16 *) dest;
> + soffset = (int) src & 15;
> + doffset = (int) dest & 15;
> +
> + if (checklen) {
> + /*
> + * Set curlen so it is the number of bytes we would copy if starting
> + * from vdest & ~0xf.
> + *
> + * curlen could probably be replaced by comparing vdest plus some
> + * offset to dest + maxlen, that would help mainly in the while loop
> + * but would lose only one instruction (the curlen -= 16).
> + */
> + curlen = spu_splats((unsigned int) (maxlen + doffset));
> + }
> +
> + /*
> + * Setup a shuffle pattern to align the source string with the
> + * alignment of the destination string.
> + */
> + vtmp = spu_cmpgt(spu_promote(doffset, 0), spu_promote(soffset, 0));
> + adjust = spu_extract(vtmp, 0);
> + offset = soffset - doffset;
> + offset += adjust & 16;
> + shuffle = spu_splats((unsigned char) offset);
> + shuffle = (vec_uchar16) spu_add((vec_uint4) shuffle, val_0123);
> +
> + vsrc += adjust;
> + sdata1 = *vsrc++;
> + sdata2 = *vsrc++;
> + sdata = spu_shuffle(sdata1, sdata2, shuffle);
> +
> + /*
> + * mask out leading bytes
> + */
> + mask1 = spu_rlmaskqwbyte(all_ones, -doffset);
> +
> + cmp0 = spu_and(mask1, spu_cmpeq(sdata, 0));
> + nonzeroes = spu_cntlz(spu_gather(cmp0));
> + /*
> + * First element of nonzeroes - 15 is the number of leading non-zero
> + * bytes plus 1 for the zero byte.
> + */
> + if (checklen) {
> + vtmp = spu_add(curlen, 15);
> + vtmp2 = spu_cmpgt(nonzeroes, vtmp);
> + nonzeroes = spu_sel(nonzeroes, vtmp, vtmp2);
> + }
> +
> + vtmp = spu_cmpgt(nonzeroes, val31);
> + /*
> + * Note: using immediate (constant 31) vs a vector value (val31) does
> + * not give different results, and we have to have a vector val31 for
> + * the spu_sel below, so use val31 everywhere.
> + */
> + vtmp = spu_sel(nonzeroes, val31, vtmp);
> + /*
> + * So vtmp is now min(nonzeroes, 31), the number of bytes + 16 that we
> + * want to copy from the first 16 bytes of the source.
> + */
> + if (checklen) {
> + curlen = spu_sub(vtmp, curlen);
> + curlen = spu_sub(15, curlen);
> + }
> +
> + /*
> + * We want a right shift 0xff with fill by ones of (vtmp - 15) bytes, but
> + * that doesn't exist so use spu_slqwbyte and vtmp all ones left by
> + * (31 - vtmp). Note: this can also use spu_rlqwbytebc with spu_rlqw.
> + */
> + shift = spu_extract(spu_sub(val31, vtmp), 0);
> + maskzero = spu_slqwbyte(all_ones, shift);
> + maskzero = spu_and(mask1, maskzero);
> + *vdest = spu_sel(*vdest, sdata, maskzero);
> +
> + vtmp = spu_cmpgt(nonzeroes, val31);
> + if (checklen) {
> + vtmp2 = spu_cmpgt(curlen, 0);
> + vtmp = spu_and(vtmp, vtmp2);
> + }
> + if (spu_extract(vtmp, 0)) {
> + sdata1 = sdata2;
> + sdata2 = *vsrc++;
> + sdata = spu_shuffle(sdata1, sdata2, shuffle);
> + cmp0 = spu_cmpeq(sdata, 0);
> + gathered_cmp = spu_gather(cmp0);
> + /*
> + * Copy 16 bytes at a time.
> + */
> + while ((spu_extract(gathered_cmp, 0) == 0) &&
> + (!checklen || (spu_extract(curlen, 0) > 15))) {
> + if (checklen)
> + curlen = spu_add(curlen, -16);
> + *++vdest = sdata;
> + sdata1 = sdata2;
> + sdata2 = *vsrc++;
> + sdata = spu_shuffle(sdata1, sdata2, shuffle);
> + cmp0 = spu_cmpeq(sdata, 0);
> + gathered_cmp = spu_gather(cmp0);
> + }
> + /*
> + * Copy 0 to 15 trailing bytes, either up to the smaller of curlen or
> + * the number of non-zero bytes.
> + */
> + nonzeroes = spu_cntlz(gathered_cmp);
> + if (checklen) {
> + vtmp = spu_add(curlen, 15);
> + vtmp2 = spu_cmpgt(nonzeroes, vtmp);
> + nonzeroes = spu_sel(nonzeroes, vtmp, vtmp2);
> + curlen = spu_sub(nonzeroes, curlen);
> + curlen = spu_sub(15, curlen);
> + }
> + shift = spu_extract(spu_sub(val31, nonzeroes), 0);
> + maskzero = spu_slqwbyte(all_ones, shift);
> + ++vdest;
> + *vdest = spu_sel(*vdest, sdata, maskzero);
> + }
> +
> + if (checklen && lastzero) {
> + /*
> + * For strncat.
> + */
> + dest[maxlen - spu_extract(curlen, 0)] = '\0';
> + }
> + return (dest);
> +}
> Index: quilt/newlib/libc/machine/spu/strcpy.c
> ===================================================================
> --- quilt.orig/newlib/libc/machine/spu/strcpy.c
> +++ quilt/newlib/libc/machine/spu/strcpy.c
> @@ -1,9 +1,6 @@
> /*
> - (C) Copyright 2001,2006,
> + (C) Copyright 2008
> International Business Machines Corporation,
> - Sony Computer Entertainment, Incorporated,
> - Toshiba Corporation,
> -
> All rights reserved.
>
> Redistribution and use in source and binary forms, with or without
> @@ -30,19 +27,15 @@
> ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
> POSSIBILITY OF SUCH DAMAGE.
> */
> -#include <spu_intrinsics.h>
> #include <stddef.h>
> +#include "strcpy.h"
>
> -/* Copy the string pointed to by src (up to and including the /0
> +/*
> + * Copy the string pointed to by src (up to and including the /0
> * character) into the array pointed to by dest. If copy between
> * two arrays that overlap, then behavior is undefined.
> */
> -
> char * strcpy(char * __restrict__ dest, const char * __restrict__ src)
> {
> - /* Due to the need to support all alignment variances, this
> - * function can not easily be optimized. As a result, it is
> - * serviced using strlen and memcpy.
> - */
> - return ((char *)memcpy((void *)dest, (const void *)src, strlen(src)+1));
> + return _strncpy(dest, src, 0, 0, 0);
> }
> Index: quilt/newlib/libc/machine/spu/strncat.c
> ===================================================================
> --- quilt.orig/newlib/libc/machine/spu/strncat.c
> +++ quilt/newlib/libc/machine/spu/strncat.c
> @@ -1,9 +1,6 @@
> /*
> - (C) Copyright 2001,2006,
> + (C) Copyright 2008
> International Business Machines Corporation,
> - Sony Computer Entertainment, Incorporated,
> - Toshiba Corporation,
> -
> All rights reserved.
>
> Redistribution and use in source and binary forms, with or without
> @@ -30,68 +27,19 @@
> ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
> POSSIBILITY OF SUCH DAMAGE.
> */
> -#include <spu_intrinsics.h>
> #include <stddef.h>
> #include <string.h>
> +#include "straddr.h"
> +#include "strcpy.h"
>
> -/* Appends the string pointed to by src (up to and including the /0
> +/*
> + * Appends the string pointed to by src (up to and including the /0
> * character) to the array pointed to by dest (overwriting the
> * /0 character at the end of dest. The strings may not overlap and
> * the dest string must have enough space for the result.
> */
> -
> -char * strncat(char * __restrict__ dest, const char * __restrict__ src, size_t n)
> +char * strncat(char * __restrict__ dest, const char * __restrict__ src,
> + size_t n)
> {
> - unsigned int cmp, skip, mask, len;
> - vec_uchar16 *ptr, data;
> - vec_uint4 cnt, gt, N;
> - char *dst;
> -
> - /* Determine the starting location to begin concatenation.
> - */
> - dst = dest + strlen(dest);
> -
> - /* Copy the src image until either the src string terminates
> - * or n characters are copied.
> - */
> - N = spu_promote((unsigned int)n, 0);
> -
> - /* Determine the string length, not including termination character,
> - * clamped to n characters.
> - */
> - ptr = (vec_uchar16 *)src;
> - skip = (unsigned int)(ptr) & 15;
> - mask = 0xFFFF >> skip;
> -
> - data = *ptr++;
> - cmp = spu_extract(spu_gather(spu_cmpeq(data, 0)), 0);
> - cmp &= mask;
> -
> - cnt = spu_cntlz(spu_promote(cmp, 0));
> - len = spu_extract(cnt, 0) - (skip + 16);
> -
> - gt = spu_cmpgt(spu_promote(len, 0), N);
> -
> - while (spu_extract(spu_andc(spu_cmpeq(cnt, 32), gt), 0)) {
> - data = *ptr++;
> - len -= 16;
> - cnt = spu_cntlz(spu_gather(spu_cmpeq(data, 0)));
> - len += spu_extract(cnt, 0);
> -
> - gt = spu_cmpgt(spu_promote(len, 0), N);
> - }
> -
> - /* len = MIN(len, n)
> - */
> - len = spu_extract(spu_sel(spu_promote(len, 0), N, gt), 0);
> -
> - /* Perform a memcpy of the resulting length
> - */
> - (void)memcpy((void *)dst, (const void *)src, len);
> -
> - /* Terminate the resulting concetenated string.
> - */
> - dst[len] = '\0';
> -
> - return (dest);
> + return _strncpy(_straddr(dest), src, n, 1, 1);
> }
> Index: quilt/newlib/libc/machine/spu/strncpy.c
> ===================================================================
> --- quilt.orig/newlib/libc/machine/spu/strncpy.c
> +++ quilt/newlib/libc/machine/spu/strncpy.c
> @@ -1,9 +1,6 @@
> /*
> - (C) Copyright 2001,2006,
> + (C) Copyright 2008
> International Business Machines Corporation,
> - Sony Computer Entertainment, Incorporated,
> - Toshiba Corporation,
> -
> All rights reserved.
>
> Redistribution and use in source and binary forms, with or without
> @@ -30,58 +27,16 @@
> ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
> POSSIBILITY OF SUCH DAMAGE.
> */
> -#include <spu_intrinsics.h>
> #include <stddef.h>
> #include <string.h>
> +#include "strcpy.h"
>
> -/* Copy the string up to n character from memory area src to
> - * memory area dest. The memory areas may not overlap. The
> - * strncpy subroutine returns a pointer to dest.
> +/*
> + * Copy the string up to n character from memory area src to memory area
> + * dest. The memory areas may not overlap. The strncpy subroutine returns
> + * a pointer to dest.
> */
> char * strncpy(char * __restrict__ dest, const char * __restrict__ src, size_t n)
> {
> - unsigned int len;
> - unsigned int cmp, skip, mask;
> - vec_uchar16 *ptr, data;
> - vec_uint4 cnt, gt, N;
> -
> - N = spu_promote((unsigned int)n, 0);
> -
> - /* Determine the string length, including termination character,
> - * clamped to n characters.
> - */
> - ptr = (vec_uchar16 *)src;
> - skip = (unsigned int)(ptr) & 15;
> - mask = 0xFFFF >> skip;
> -
> - data = *ptr++;
> - cmp = spu_extract(spu_gather(spu_cmpeq(data, 0)), 0);
> - cmp &= mask;
> -
> - cnt = spu_cntlz(spu_promote(cmp, 0));
> - len = spu_extract(cnt, 0) - (skip + 15);
> -
> - gt = spu_cmpgt(spu_promote(len, 0), N);
> -
> - while (spu_extract(spu_andc(spu_cmpeq(cnt, 32), gt), 0)) {
> - data = *ptr++;
> - len -= 16;
> - cnt = spu_cntlz(spu_gather(spu_cmpeq(data, 0)));
> - len += spu_extract(cnt, 0);
> -
> - gt = spu_cmpgt(spu_promote(len, 0), N);
> - }
> -
> - /* len = MIN(len, n)
> - */
> - len = spu_extract(spu_sel(spu_promote((unsigned int)len, 0), N, gt), 0);
> -
> - /* Padding
> - */
> - if (len != n) {
> - memset(dest + len, 0, n - len);
> - }
> - /* Perform a memcpy of the resulting length
> - */
> - return ((char *)memcpy((void *)dest, (const void *)src, len));
> + return _strncpy(dest, src, n, 1, 0);
> }
> Index: quilt/newlib/libc/machine/spu/straddr.h
> ===================================================================
> --- /dev/null
> +++ quilt/newlib/libc/machine/spu/straddr.h
> @@ -0,0 +1,75 @@
> +/*
> + (C) Copyright 2008
> + International Business Machines Corporation,
> + All rights reserved.
> +
> + Redistribution and use in source and binary forms, with or without
> + modification, are permitted provided that the following conditions are met:
> +
> + * Redistributions of source code must retain the above copyright notice,
> + this list of conditions and the following disclaimer.
> + * Redistributions in binary form must reproduce the above copyright
> + notice, this list of conditions and the following disclaimer in the
> + documentation and/or other materials provided with the distribution.
> + * Neither the names of the copyright holders nor the names of their
> + contributors may be used to endorse or promote products derived from
> + this software without specific prior written permission.
> +
> + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
> + IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
> + TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
> + PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
> + OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
> + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
> + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
> + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
> + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
> + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
> + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> +*/
> +
> +#include <spu_intrinsics.h>
> +#include "vec_literal.h"
> +
> +/*
> + * Supply the inline _straddr for use by strncpy and strncat.
> +*
> +* _straddr: search the string s, and return the address of the first byte
> +* containing zero.
> +*/
> +static inline char *_straddr(const char *s)
> +{
> + unsigned int cnt, cmp, skip, mask;
> + vec_uchar16 *ptr, data;
> +
> + /*
> + * Compensate for unaligned strings.
> + */
> + ptr = (vec_uchar16 *)s; /* implicit (s & ~0xf) */
> + skip = (unsigned int)(ptr) & 0xf;
> + /*
> + * skip the first skip bytes starting at (s & ~0xf).
> + */
> + mask = 0xFFFF >> skip;
> +
> + data = *ptr;
> + cmp = spu_extract(spu_gather(spu_cmpeq(data, 0)), 0);
> + cmp &= mask;
> +
> + cnt = spu_extract(spu_cntlz(spu_promote(cmp, 0)), 0);
> +
> + while (cnt == 32) {
> + data = *++ptr;
> + cnt = spu_extract(spu_cntlz(spu_gather(spu_cmpeq(data, 0))), 0);
> + /*
> + * The first 16 bits for gather on a byte vector are zero, so if cnt
> + * is 32, none of the 16 bytes in data was zero. And, there are (cnt -
> + * 16) non-zero bytes in data.
> + */
> + }
> + /*
> + * The first non-zero byte is at ptr aligned down plus the number of
> + * non-zero bytes seen.
> + */
> + return ((char*) (((int) ptr & ~0xf) + (cnt - 16)));
> +}
>
>
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