const_rtx_hash_1 had code to hash all elements of a CONST_VECTOR,
but const_rtx_hash also hashes all subrtxes, so we'd end up hashing
the same thing twice. This looked unintentional so I just removed the
CONST_VECTOR case. If instead it was a deliberate decision then I think
it deserves a comment.
gcc/
* varasm.c: Include rtl-iter.h.
(const_rtx_hash_1): Take a const_rtx rather than an rtx *.
Remove the pointer to the cumulative hashval_t and just return
the hash for this rtx instead. Remove recursive CONST_VECTOR case.
(const_rtx_hash): Use FOR_EACH_SUBRTX instead of for_each_rtx.
Accumulate the hashval_ts here instead of const_rtx_hash_1.
Index: gcc/varasm.c
===================================================================
--- gcc/varasm.c 2014-08-03 11:25:30.450157225 +0100
+++ gcc/varasm.c 2014-08-03 11:25:33.667189030 +0100
@@ -54,6 +54,7 @@ Software Foundation; either version 3, o
#include "hash-set.h"
#include "asan.h"
#include "basic-block.h"
+#include "rtl-iter.h"
#ifdef XCOFF_DEBUGGING_INFO
#include "xcoffout.h" /* Needed for external data
@@ -3481,19 +3482,17 @@ const_desc_rtx_eq (const void *a, const
return rtx_equal_p (x->constant, y->constant);
}
-/* This is the worker function for const_rtx_hash, called via for_each_rtx. */
+/* Hash one component of a constant. */
-static int
-const_rtx_hash_1 (rtx *xp, void *data)
+static hashval_t
+const_rtx_hash_1 (const_rtx x)
{
unsigned HOST_WIDE_INT hwi;
enum machine_mode mode;
enum rtx_code code;
- hashval_t h, *hp;
- rtx x;
+ hashval_t h;
int i;
- x = *xp;
code = GET_CODE (x);
mode = GET_MODE (x);
h = (hashval_t) code * 1048573 + mode;
@@ -3539,14 +3538,6 @@ const_rtx_hash_1 (rtx *xp, void *data)
h ^= fixed_hash (CONST_FIXED_VALUE (x));
break;
- case CONST_VECTOR:
- {
- int i;
- for (i = XVECLEN (x, 0); i-- > 0; )
- h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
- }
- break;
-
case SYMBOL_REF:
h ^= htab_hash_string (XSTR (x, 0));
break;
@@ -3564,9 +3555,7 @@ const_rtx_hash_1 (rtx *xp, void *data)
break;
}
- hp = (hashval_t *) data;
- *hp = *hp * 509 + h;
- return 0;
+ return h;
}
/* Compute a hash value for X, which should be a constant. */
@@ -3575,7 +3564,9 @@ const_rtx_hash_1 (rtx *xp, void *data)
const_rtx_hash (rtx x)
{
hashval_t h = 0;
- for_each_rtx (&x, const_rtx_hash_1, &h);
+ subrtx_iterator::array_type array;
+ FOR_EACH_SUBRTX (iter, array, x, ALL)
+ h = h * 509 + const_rtx_hash_1 (*iter);
return h;
}
