From 9ab183e388057e53a84234a9f82d797b314b0419 Mon Sep 17 00:00:00 2001
From: sayle <sayle@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue, 12 Sep 2006 16:02:31 +0000
Subject: [PATCH] PR middle-end/4520 PR bootstrap/28784 *
cselib.c (cselib_hash_rtx): Avoid hashing on the address of labels and
symbols. Instead use the implementation from cse.c's hash_rtx.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@116891 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/ChangeLog | 7 +++++++
gcc/cselib.c | 24 +++++++++++++++++++-----
2 files changed, 26 insertions(+), 5 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5d66902f67fb..0a0d31b8cf27 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2006-09-12 Roger Sayle <roger@eyesopen.com>
+
+ PR middle-end/4520
+ PR bootstrap/28784
+ * cselib.c (cselib_hash_rtx): Avoid hashing on the address of labels
+ and symbols. Instead use the implementation from cse.c's hash_rtx.
+
2006-09-12 Jan Hubicka <jh@suse.cz>
PR rtl-optimization/28071
diff --git a/gcc/cselib.c b/gcc/cselib.c
index edfc328c0d84..4070da7c01f0 100644
--- a/gcc/cselib.c
+++ b/gcc/cselib.c
@@ -630,14 +630,28 @@ cselib_hash_rtx (rtx x, int create)
/* Assume there is only one rtx object for any given label. */
case LABEL_REF:
- hash
- += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0);
+ /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
+ differences and differences between each stage's debugging dumps. */
+ hash += (((unsigned int) LABEL_REF << 7)
+ + CODE_LABEL_NUMBER (XEXP (x, 0)));
return hash ? hash : (unsigned int) LABEL_REF;
case SYMBOL_REF:
- hash
- += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0);
- return hash ? hash : (unsigned int) SYMBOL_REF;
+ {
+ /* Don't hash on the symbol's address to avoid bootstrap differences.
+ Different hash values may cause expressions to be recorded in
+ different orders and thus different registers to be used in the
+ final assembler. This also avoids differences in the dump files
+ between various stages. */
+ unsigned int h = 0;
+ const unsigned char *p = (const unsigned char *) XSTR (x, 0);
+
+ while (*p)
+ h += (h << 7) + *p++; /* ??? revisit */
+
+ hash += ((unsigned int) SYMBOL_REF << 7) + h;
+ return hash ? hash : (unsigned int) SYMBOL_REF;
+ }
case PRE_DEC:
case PRE_INC:
--
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