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/strchr.c b/libc/arch-mips/string/strchr.c
new file mode 100644
index 0000000..c9397e7
--- /dev/null
+++ b/libc/arch-mips/string/strchr.c
@@ -0,0 +1,138 @@
+/*
+ * 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 op_t unsigned long int
+#define op_size sizeof (op_t)
+
+#if __mips64
+typedef struct
+{
+ op_t B0:8, B1:8, B2:8, B3:8, B4:8, B5:8, B6:8, B7:8;
+} bits_t;
+#else
+typedef struct
+{
+ op_t B0:8, B1:8, B2:8, B3:8;
+} bits_t;
+#endif
+
+typedef union
+{
+ op_t v;
+ bits_t b;
+} bitfields_t;
+
+#define DO_BYTE(i) \
+ if (a.b.B##i != ch) { \
+ if(a.b.B##i == '\0') return 0; \
+ p++; \
+ } else \
+ return (char *)p;
+
+#define DO_WORD(w, cnt) { \
+ op_t val = w[cnt] ^ mask_c; \
+ if ((((w[cnt] - mask_1) & ~w[cnt]) & mask_128) || \
+ (((val - mask_1) & ~val) & mask_128)) { \
+ return do_bytes(w + cnt, ch); \
+ } \
+}
+
+static inline char * __attribute__ ((always_inline))
+do_bytes (const op_t* w, unsigned char ch)
+{
+ bitfields_t a;
+ unsigned char* p = (unsigned char *) w;
+ a.v = *w;
+#if __mips64
+ DO_BYTE(0)
+ DO_BYTE(1)
+ DO_BYTE(2)
+ DO_BYTE(3)
+ DO_BYTE(4)
+ DO_BYTE(5)
+ DO_BYTE(6)
+ DO_BYTE(7)
+#else
+ DO_BYTE(0)
+ DO_BYTE(1)
+ DO_BYTE(2)
+ DO_BYTE(3)
+#endif
+ return (char *)p;
+}
+
+char* strchr(const char* s, int c) __overloadable
+{
+ const op_t *w;
+ op_t mask_1, mask_128, mask_c;
+ const unsigned char ch = c;
+ unsigned char* p = (unsigned char *) s;
+
+ /*
+ * Check byte by byte till initial alignment
+ */
+ for ( ; *p != ch && ((size_t) p % op_size) != 0; p++)
+ if (*p == '\0')
+ return 0;
+
+ if (*p != ch) {
+ 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 word/dword wize after initial alignment till character match
+ * or end of string
+ */
+ while (1) {
+ DO_WORD(w, 0)
+ DO_WORD(w, 1)
+ DO_WORD(w, 2)
+ DO_WORD(w, 3)
+ w += 4;
+ }
+ }
+
+ return (char *)p;
+}