Jeff -
Can you please apply?
Get rid of len variable in strlen code.
This does not change the size or speed of the code for -O2 (it does for
-O1), but makes the source a bit simpler to read.
newlib/ChangeLog:
2008-02-11 Patrick Mansfield <patmans@us.ibm.com>
* libc/machine/spu/strlen.c: Remove the len variable and unneeded
calculation of its value.
Index: src/newlib/libc/machine/spu/strlen.c
===================================================================
--- src.orig/newlib/libc/machine/spu/strlen.c
+++ src/newlib/libc/machine/spu/strlen.c
@@ -33,34 +33,36 @@
#include <spu_intrinsics.h>
#include <stddef.h>
-/* Calculates the length of the string s, not including the terminating
+/*
+ * Calculates the length of the string s, not including the terminating
* \0 character.
*/
size_t strlen(const char *s)
{
- size_t len;
unsigned int cnt, cmp, skip, mask;
vec_uchar16 *ptr, data;
- /* Compensate for initial mis-aligned string.
+ /*
+ * Compensate for initial mis-aligned string.
*/
- ptr = (vec_uchar16 *)s;
+ ptr = (vec_uchar16 *)s; /* implicit 16 byte alignment when dereferenced */
skip = (unsigned int)(ptr) & 15;
mask = 0xFFFF >> skip;
- data = *ptr++;
+ data = *ptr;
cmp = spu_extract(spu_gather(spu_cmpeq(data, 0)), 0);
cmp &= mask;
cnt = spu_extract(spu_cntlz(spu_promote(cmp, 0)), 0);
- len = cnt - (skip + 16);
while (cnt == 32) {
- data = *ptr++;
- len -= 16;
+ data = *++ptr;
cnt = spu_extract(spu_cntlz(spu_gather(spu_cmpeq(data, 0))), 0);
- len += cnt;
}
- return (len);
+ /*
+ * The length is ptr aligned down to a 16 byte boundary, plus the offset
+ * to the zero byte, minus the starting address s.
+ */
+ return ((((int) ptr & ~0xf) + (cnt - 16)) - (int) s);
}