From 38fbc003332134ef0a04d319fb71b297f67c6988 Mon Sep 17 00:00:00 2001
From: Richard Sandiford <richard.sandiford@linaro.org>
Date: Mon, 21 Aug 2017 09:46:05 +0000
Subject: [PATCH] Fix bogus CONST_WIDE_INT hash

The CONST_WIDE_INT case in const_rtx_hash_1 started the hash
with the precision of the mode, but the mode is always VOIDmode.

2017-08-21  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* varasm.c (const_rtx_hash_1): Don't hash in the mode of a
	CONST_WIDE_INT.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r251218
---
 gcc/ChangeLog | 7 +++++++
 gcc/varasm.c  | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 213b5c803ab..34ecfdc8188 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2017-08-21  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
+	* varasm.c (const_rtx_hash_1): Don't hash in the mode of a
+	CONST_WIDE_INT.
+
 2017-08-21  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/81884
diff --git a/gcc/varasm.c b/gcc/varasm.c
index e0834a1ff3b..91680d692b4 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -3639,7 +3639,7 @@ const_rtx_hash_1 (const_rtx x)
       break;
 
     case CONST_WIDE_INT:
-      hwi = GET_MODE_PRECISION (mode);
+      hwi = 0;
       {
 	for (i = 0; i < CONST_WIDE_INT_NUNITS (x); i++)
 	  hwi ^= CONST_WIDE_INT_ELT (x, i);
-- 
2.30.2