[libiberty] remove TBAA violation in iterative_hash, improve code-gen

[thirdparty/gcc.git] / libiberty / hashtab.c

diff --git a/libiberty/hashtab.c b/libiberty/hashtab.c
index 48f28078114edf007e04a30a474bd20d4c3b080f..e3a07256a300f71913b6c316f9306f2a5f2a9c29 100644 (file)
--- a/libiberty/hashtab.c
+++ b/libiberty/hashtab.c
@@ -940,26 +940,23 @@ iterative_hash (const void *k_in /* the key */,
   c = initval;           /* the previous hash value */
 
   /*---------------------------------------- handle most of the key */
-#ifndef WORDS_BIGENDIAN
-  /* On a little-endian machine, if the data is 4-byte aligned we can hash
-     by word for better speed.  This gives nondeterministic results on
-     big-endian machines.  */
-  if (sizeof (hashval_t) == 4 && (((size_t)k)&3) == 0)
-    while (len >= 12)    /* aligned */
+  /* Provide specialization for the aligned case for targets that cannot
+     efficiently perform misaligned loads of a merged access.  */
+  if ((((size_t)k)&3) == 0)
+    while (len >= 12)
       {
-       a += *(hashval_t *)(k+0);
-       b += *(hashval_t *)(k+4);
-       c += *(hashval_t *)(k+8);
+       a += (k[0] | ((hashval_t)k[1]<<8) | ((hashval_t)k[2]<<16) | ((hashval_t)k[3]<<24));
+       b += (k[4] | ((hashval_t)k[5]<<8) | ((hashval_t)k[6]<<16) | ((hashval_t)k[7]<<24));
+       c += (k[8] | ((hashval_t)k[9]<<8) | ((hashval_t)k[10]<<16)| ((hashval_t)k[11]<<24));
        mix(a,b,c);
        k += 12; len -= 12;
       }
   else /* unaligned */
-#endif
     while (len >= 12)
       {
-       a += (k[0] +((hashval_t)k[1]<<8) +((hashval_t)k[2]<<16) +((hashval_t)k[3]<<24));
-       b += (k[4] +((hashval_t)k[5]<<8) +((hashval_t)k[6]<<16) +((hashval_t)k[7]<<24));
-       c += (k[8] +((hashval_t)k[9]<<8) +((hashval_t)k[10]<<16)+((hashval_t)k[11]<<24));
+       a += (k[0] | ((hashval_t)k[1]<<8) | ((hashval_t)k[2]<<16) | ((hashval_t)k[3]<<24));
+       b += (k[4] | ((hashval_t)k[5]<<8) | ((hashval_t)k[6]<<16) | ((hashval_t)k[7]<<24));
+       c += (k[8] | ((hashval_t)k[9]<<8) | ((hashval_t)k[10]<<16)| ((hashval_t)k[11]<<24));
        mix(a,b,c);
        k += 12; len -= 12;
       }