Add libc optimizations to bionic for MIPS
Test: Used bionic tests available under bionic/tests folder.
Tested for mips32r1/mips32r2/mips64r6 on emulators.
Change-Id: I589415ddc496df3f6067ae34cb33ca58b3a1f276
Signed-off-by: Prashant Patil <prashant.patil@imgtec.com>
diff --git a/libc/arch-mips/string/memchr.c b/libc/arch-mips/string/memchr.c
new file mode 100644
index 0000000..6b4c8cc
--- /dev/null
+++ b/libc/arch-mips/string/memchr.c
@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2017 Imagination Technologies.
+ *
+ * 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 name of Imagination Technologies nor the names of its
+ * 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 <string.h>
+
+#define ENABLE_PREFETCH 1
+#define op_t unsigned long int
+#define op_size sizeof (op_t)
+
+#if ENABLE_PREFETCH
+#define PREFETCH(addr) __builtin_prefetch (addr, 0, 1);
+#else
+#define PREFETCH(addr)
+#endif
+
+#if __mips64 || __mips_isa_rev >= 2
+static inline void * __attribute__ ((always_inline))
+do_bytes (const op_t* w, op_t inval)
+{
+ const unsigned char *p = (const unsigned char *) w;
+ op_t outval = 0;
+#if __mips64
+ __asm__ volatile (
+ "dsbh %1, %0 \n\t"
+ "dshd %0, %1 \n\t"
+ "dclz %1, %0 \n\t"
+ : "+r" (inval), "+r" (outval)
+ );
+#else
+ __asm__ volatile (
+ "wsbh %1, %0 \n\t"
+ "rotr %0, %1, 16 \n\t"
+ "clz %1, %0 \n\t"
+ : "+r" (inval), "+r" (outval)
+ );
+#endif
+ p += (outval >> 3);
+ return (void *) p;
+}
+
+#define DO_WORD(in, val) { \
+ op_t tmp = ((val - mask_1) & ~val) & mask_128; \
+ if (tmp != 0) \
+ return do_bytes(in, tmp); \
+}
+#else
+static inline void * __attribute__ ((always_inline))
+do_bytes (const op_t* w, unsigned char ch)
+{
+ const unsigned char *p = (const unsigned char *) w;
+ for (; *p != ch; ++p);
+ return (void *) p;
+}
+
+#define DO_WORD(in, val) { \
+ op_t tmp = ((val - mask_1) & ~val) & mask_128; \
+ if (tmp != 0) \
+ return do_bytes(in, ch); \
+}
+#endif
+
+#define DO_WORDS(w) { \
+ op_t* w1 = (op_t*) w; \
+ op_t val0 = w1[0] ^ mask_c; \
+ op_t val1 = w1[1] ^ mask_c; \
+ op_t val2 = w1[2] ^ mask_c; \
+ op_t val3 = w1[3] ^ mask_c; \
+ DO_WORD(w1, val0) \
+ DO_WORD(w1 + 1, val1) \
+ DO_WORD(w1 + 2, val2) \
+ DO_WORD(w1 + 3, val3) \
+}
+
+void *
+memchr (void const *s, int c_in, size_t n) __overloadable
+{
+ if (n != 0) {
+ const unsigned char *p = (const unsigned char *) s;
+ const op_t *w;
+ op_t mask_1, mask_128, mask_c;
+ unsigned char ch = (unsigned char) c_in;
+
+ /*
+ * Check bytewize till initial alignment
+ */
+ for (; n > 0 && ((size_t) p % op_size) != 0; --n, ++p) {
+ if (*p == ch)
+ return (void *) p;
+ }
+
+ w = (const op_t *) p;
+
+ mask_c = ch | (ch << 8);
+ mask_c |= mask_c << 16;
+ __asm__ volatile (
+ "li %0, 0x01010101 \n\t"
+ : "=r" (mask_1)
+ );
+#if __mips64
+ mask_1 |= mask_1 << 32;
+ mask_c |= mask_c << 32;
+#endif
+ mask_128 = mask_1 << 7;
+
+ /*
+ * Check op_size byteswize after initial alignment
+ */
+#if ((_MIPS_SIM == _ABIO32) || _MIPS_TUNE_I6400)
+ PREFETCH (w);
+ PREFETCH (w + 8);
+ while (n >= 24 * op_size) {
+ PREFETCH(w + 16);
+ DO_WORDS(w);
+ DO_WORDS(w + 4);
+ w += 8;
+ n -= 8 * op_size;
+ }
+ while (n >= 8 * op_size) {
+ DO_WORDS(w);
+ DO_WORDS(w + 4);
+ w += 8;
+ n -= 8 * op_size;
+ }
+#else
+ PREFETCH (w);
+ PREFETCH (w + 4);
+ while (n >= 12 * op_size) {
+ PREFETCH(w + 8);
+ DO_WORDS(w);
+ w += 4;
+ n -= 4 * op_size;
+ }
+ while (n >= 4 * op_size) {
+ DO_WORDS(w);
+ w += 4;
+ n -= 4 * op_size;
+ }
+#endif
+
+ while (n >= op_size) {
+ op_t val = *w ^ mask_c;
+ DO_WORD(w, val);
+ w++;
+ n -= op_size;
+ }
+
+ /*
+ * Check bytewize for remaining bytes
+ */
+ p = (const unsigned char *) w;
+ for (; n > 0; --n, ++p) {
+ if (*p == ch)
+ return (void *) p;
+ }
+ }
+ return NULL;
+}