From 0ffc3b94a0cc452f63eb977633e844dae8539f3a Mon Sep 17 00:00:00 2001
From: Nick Clifton <nickc@redhat.com>
Date: Thu, 30 Nov 2000 01:57:27 +0000
Subject: Add support for Intel's XScale processor

---
 newlib/libc/machine/xscale/memchr.c | 102 ++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 newlib/libc/machine/xscale/memchr.c

(limited to 'newlib/libc/machine/xscale/memchr.c')

diff --git a/newlib/libc/machine/xscale/memchr.c b/newlib/libc/machine/xscale/memchr.c
new file mode 100644
index 000000000..fc24bf66e
--- /dev/null
+++ b/newlib/libc/machine/xscale/memchr.c
@@ -0,0 +1,102 @@
+#if defined __thumb__
+
+#include "../../string/memchr.c"
+
+#else
+
+#include <string.h>
+#include "xscale.h"
+
+void *
+memchr (const void *start, int c, size_t len)
+{
+  const char *str = start;
+
+  if (len == 0)
+    return 0;
+
+  asm (PRELOADSTR ("%0") : : "r" (start));
+
+  c &= 0xff;
+
+#ifndef __OPTIMIZE_SIZE__
+  /* Skip unaligned part.  */
+  if ((long)str & 3)
+    {
+      str--;
+      do
+	{
+	  if (*++str == c)
+	    return (void *)str;
+	}
+      while (((long)str & 3) != 0 && --len > 0);
+    }
+
+  if (len > 3)
+    {
+      unsigned int c2 = c + (c << 8);
+      c2 += c2 << 16;
+
+      /* Load two constants:
+         R7 = 0xfefefeff [ == ~(0x80808080 << 1) ]
+         R6 = 0x80808080  */
+
+      asm (
+       "mov	r6, #0x80
+	add	r6, r6, #0x8000
+	add	r6, r6, r6, lsl #16
+	mvn	r7, r6, lsl #1
+
+0:
+	cmp	%1, #0x7
+	bls	1f
+
+	ldmia	%0!, { r3, r9 }
+"	PRELOADSTR ("%0") "
+	sub	%1, %1, #8
+	eor	r3, r3, %2
+	eor	r9, r9, %2
+	add	r2, r3, r7
+	add	r8, r9, r7
+	bic	r2, r2, r3
+	bic	r8, r8,	r9
+	and	r1, r2, r6
+	and	r9, r8, r6
+	orrs	r1, r1, r9
+	beq	0b
+
+	add	%1, %1, #8
+	sub	%0, %0, #8
+1:
+	cmp	%1, #0x3
+	bls	2f
+
+	ldr	r3, [%0], #4
+"	PRELOADSTR ("%0") "
+	sub	%1, %1, #4
+	eor	r3, r3, %2
+	add	r2, r3, r7
+	bic	r2, r2, r3
+	ands	r1, r2, r6
+	beq	1b
+
+	sub	%0, %0, #4
+	add	%1, %1, #4
+2:
+"
+       : "=&r" (str), "=&r" (len)
+       : "r" (c2), "0" (str), "1" (len)
+       : "r1", "r2", "r3", "r6", "r7", "r8", "r9", "cc");
+    }
+#endif
+
+  while (len-- > 0)
+    { 
+      if (*str == c)
+        return (void *)str;
+      str++;
+    } 
+
+  return 0;
+}
+#endif
-- 
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