1 files changed, 133 insertions, 0 deletions
diff --git a/string/arm/strcpy.c b/string/arm/strcpy.c
new file mode 100644
index 000000000000..02cf94ff4be0
--- /dev/null
+++ b/string/arm/strcpy.c
@@ -0,0 +1,133 @@
+/*
+ * strcpy
+ *
+ * Copyright (c) 2008-2020, Arm Limited.
+ * SPDX-License-Identifier: MIT
+ */
+
+#if defined (__thumb2__) && !defined (__thumb__)
+
+/* For GLIBC:
+#include <string.h>
+#include <memcopy.h>
+
+#undef strcmp
+*/
+
+#ifdef __thumb2__
+#define magic1(REG) "#0x01010101"
+#define magic2(REG) "#0x80808080"
+#else
+#define magic1(REG) #REG
+#define magic2(REG) #REG ", lsl #7"
+#endif
+
+char* __attribute__((naked))
+__strcpy_arm (char* dst, const char* src)
+{
+  __asm__ (
+       "pld	[r1, #0]\n\t"
+       "eor	r2, r0, r1\n\t"
+       "mov	ip, r0\n\t"
+       "tst	r2, #3\n\t"
+       "bne	4f\n\t"
+       "tst	r1, #3\n\t"
+       "bne	3f\n"
+  "5:\n\t"
+# ifndef __thumb2__
+       "str	r5, [sp, #-4]!\n\t"
+       "mov	r5, #0x01\n\t"
+       "orr	r5, r5, r5, lsl #8\n\t"
+       "orr	r5, r5, r5, lsl #16\n\t"
+# endif
+
+       "str	r4, [sp, #-4]!\n\t"
+       "tst	r1, #4\n\t"
+       "ldr	r3, [r1], #4\n\t"
+       "beq	2f\n\t"
+       "sub	r2, r3, "magic1(r5)"\n\t"
+       "bics	r2, r2, r3\n\t"
+       "tst	r2, "magic2(r5)"\n\t"
+       "itt	eq\n\t"
+       "streq	r3, [ip], #4\n\t"
+       "ldreq	r3, [r1], #4\n"
+       "bne	1f\n\t"
+       /* Inner loop.  We now know that r1 is 64-bit aligned, so we
+	  can safely fetch up to two words.  This allows us to avoid
+	  load stalls.  */
+       ".p2align 2\n"
+  "2:\n\t"
+       "pld	[r1, #8]\n\t"
+       "ldr	r4, [r1], #4\n\t"
+       "sub	r2, r3, "magic1(r5)"\n\t"
+       "bics	r2, r2, r3\n\t"
+       "tst	r2, "magic2(r5)"\n\t"
+       "sub	r2, r4, "magic1(r5)"\n\t"
+       "bne	1f\n\t"
+       "str	r3, [ip], #4\n\t"
+       "bics	r2, r2, r4\n\t"
+       "tst	r2, "magic2(r5)"\n\t"
+       "itt	eq\n\t"
+       "ldreq	r3, [r1], #4\n\t"
+       "streq	r4, [ip], #4\n\t"
+       "beq	2b\n\t"
+       "mov	r3, r4\n"
+  "1:\n\t"
+# ifdef __ARMEB__
+       "rors	r3, r3, #24\n\t"
+# endif
+       "strb	r3, [ip], #1\n\t"
+       "tst	r3, #0xff\n\t"
+# ifdef __ARMEL__
+       "ror	r3, r3, #8\n\t"
+# endif
+       "bne	1b\n\t"
+       "ldr	r4, [sp], #4\n\t"
+# ifndef __thumb2__
+       "ldr	r5, [sp], #4\n\t"
+# endif
+       "BX LR\n"
+
+       /* Strings have the same offset from word alignment, but it's
+	  not zero.  */
+  "3:\n\t"
+       "tst	r1, #1\n\t"
+       "beq	1f\n\t"
+       "ldrb	r2, [r1], #1\n\t"
+       "strb	r2, [ip], #1\n\t"
+       "cmp	r2, #0\n\t"
+       "it	eq\n"
+       "BXEQ LR\n"
+  "1:\n\t"
+       "tst	r1, #2\n\t"
+       "beq	5b\n\t"
+       "ldrh	r2, [r1], #2\n\t"
+# ifdef __ARMEB__
+       "tst	r2, #0xff00\n\t"
+       "iteet	ne\n\t"
+       "strneh	r2, [ip], #2\n\t"
+       "lsreq	r2, r2, #8\n\t"
+       "streqb	r2, [ip]\n\t"
+       "tstne	r2, #0xff\n\t"
+# else
+       "tst	r2, #0xff\n\t"
+       "itet	ne\n\t"
+       "strneh	r2, [ip], #2\n\t"
+       "streqb	r2, [ip]\n\t"
+       "tstne	r2, #0xff00\n\t"
+# endif
+       "bne	5b\n\t"
+       "BX LR\n"
+
+       /* src and dst do not have a common word-alignement.  Fall back to
+	  byte copying.  */
+  "4:\n\t"
+       "ldrb	r2, [r1], #1\n\t"
+       "strb	r2, [ip], #1\n\t"
+       "cmp	r2, #0\n\t"
+       "bne	4b\n\t"
+       "BX LR");
+}
+/* For GLIBC: libc_hidden_builtin_def (strcpy) */
+
+#endif /* defined (__thumb2__) && !defined (__thumb__)  */