1 files changed, 92 insertions, 7 deletions

diff --git a/newlib/libc/machine/spu/strncmp.c b/newlib/libc/machine/spu/strncmp.c
index d96504ca6..54d1fb9f4 100644
--- a/newlib/libc/machine/spu/strncmp.c
+++ b/newlib/libc/machine/spu/strncmp.c
@@ -30,17 +30,102 @@
   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   POSSIBILITY OF SUCH DAMAGE.
 */
-#include <stddef.h>
 #include <spu_intrinsics.h>
-#include "strncmp.h"
+#include <stddef.h>
+#include "vec_literal.h"
 
-/*
- * Compare the two strings s1 and s2 of length n. Returns an integer less
- * than, equal to, or greater than zero if s1 is found, respectively,
+/* Compare the two strings s1 and s2 of length n.  Returns an integer
+ * less than, equal to, or greater than zero if  s1  is  found, respectively,
  * to be less than, to match, or be greater than s2.
  */
+
 int strncmp(const char *s1, const char *s2, size_t n)
 {
-  vec_uint4 end_v;
-  return _strncmp_internal (s1, s2, n, &end_v, 1);
+  unsigned int offset1, offset2;
+  vec_int4 n_v;
+  vec_uint4 cnt1_v, cnt2_v, max_cnt_v;
+  vec_uint4 gt_v, lt_v, mask_v, end1_v, end2_v, end_v, neq_v;
+  vec_uint4 shift_n_v, shift_eos_v, max_shift_v;
+  vec_uchar16 shuffle1, shuffle2;
+  vec_uchar16 data1A, data1B, data1, data2A, data2B, data2;
+  vec_uchar16 *ptr1, *ptr2;
+
+  data1 = data2 = spu_splats((unsigned char)0);
+
+  ptr1 = (vec_uchar16 *)s1;
+  ptr2 = (vec_uchar16 *)s2;
+
+  offset1 = (unsigned int)(ptr1) & 15;
+  offset2 = (unsigned int)(ptr2) & 15;
+
+  shuffle1 = (vec_uchar16)spu_add((vec_uint4)spu_splats((unsigned char)offset1),
+				  VEC_LITERAL(vec_uint4, 0x00010203, 0x04050607, 0x08090A0B, 0x0C0D0E0F));
+  shuffle2 = (vec_uchar16)spu_add((vec_uint4)spu_splats((unsigned char)offset2),
+				  VEC_LITERAL(vec_uint4, 0x00010203, 0x04050607, 0x08090A0B, 0x0C0D0E0F));
+  data1A = *ptr1++;
+  data2A = *ptr2++;
+
+  n_v = spu_promote((int)n, 0);
+
+  do {
+    data1B = *ptr1++;
+    data2B = *ptr2++;
+
+    /* Quadword align each of the input strings so that
+     * we operate on full quadwords.
+     */
+    data1 = spu_shuffle(data1A, data1B, shuffle1);
+    data2 = spu_shuffle(data2A, data2B, shuffle2);
+
+    data1A = data1B;
+    data2A = data2B;
+
+    neq_v = spu_gather(spu_xor(spu_cmpeq(data1, data2), -1));
+
+    end1_v = spu_gather(spu_cmpeq(data1, 0));
+    end2_v = spu_gather(spu_cmpeq(data2, 0));
+    end_v  = spu_or(end1_v, end2_v), 0;
+
+    n_v = spu_add(n_v, -16);
+
+    /* Repeat until either
+     * 1) the character count expired,
+     * 2) a null character is discovered in one of the input strings, or
+     * 3) the strings do not compare equal.
+     */
+  } while (spu_extract(spu_and(spu_cmpeq(spu_or(end_v, neq_v), 0), spu_cmpgt(n_v, 0)), 0));
+
+  /* Construct a mask to eliminate characters that are not of interest
+   * in the comparison. Theses include characters that are beyond the
+   * n character count and beyond the first null character.
+   */
+  cnt1_v = spu_cntlz(end1_v);
+  cnt2_v = spu_cntlz(end2_v);
+
+  max_cnt_v = spu_sel(cnt1_v, cnt2_v, spu_cmpgt(cnt2_v, cnt1_v));
+
+  mask_v = spu_splats((unsigned int)0xFFFF);
+
+  shift_n_v = spu_andc((__vector unsigned int)spu_sub(0, n_v), spu_cmpgt(n_v, -1));
+  shift_eos_v = spu_sub(32, max_cnt_v);
+
+  max_shift_v = spu_sel(shift_n_v, shift_eos_v, spu_cmpgt(shift_eos_v, shift_n_v));
+
+  mask_v = spu_and(spu_sl(mask_v, spu_extract(max_shift_v, 0)), mask_v);
+
+  /* Determine if greater then or less then in the case that they are
+   * not equal. gt_v is either 1 (in the case s1 is greater then s2), or
+   * -1 (in the case that s2 is greater then s1).
+   */
+  gt_v = spu_gather(spu_cmpgt(data1, data2));
+  lt_v = spu_gather(spu_cmpgt(data2, data1));
+
+  gt_v = spu_sub(-1, spu_sl(spu_cmpgt(gt_v, lt_v), 1));
+
+  /* Construct a mask to be applied to gt_v if the strings are discovered
+   * to be equal.
+   */
+  mask_v = spu_cmpeq(spu_and(neq_v, mask_v), 0);
+
+  return (spu_extract(spu_andc(gt_v, mask_v), 0));
 }