From: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Wed, 2 Nov 2016 09:25:22 +0000 (+0000)
Subject: PR tree-optimization/78162: Reject negative offsets in store merging early
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=63e523d6f0853765adc332c7a68a8e6b16971d6b;p=gcc.git

PR tree-optimization/78162: Reject negative offsets in store merging early

	PR tree-optimization/78162
	* gimple-ssa-store-merging.c (execute): Mark stores with bitpos < 0
	as invalid.

	* gcc.c-torture/compile/pr78162.c: New test.

From-SVN: r241778
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 52215f6eebf..aee2b83f8b3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-11-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR tree-optimization/78162
+	* gimple-ssa-store-merging.c (execute): Mark stores with bitpos < 0
+	as invalid.
+
 2016-11-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/aarch64/aarch64.c (aarch64_register_saved_on_entry): Add
diff --git a/gcc/gimple-ssa-store-merging.c b/gcc/gimple-ssa-store-merging.c
index 97af1418c97..feba907559f 100644
--- a/gcc/gimple-ssa-store-merging.c
+++ b/gcc/gimple-ssa-store-merging.c
@@ -1361,7 +1361,7 @@ pass_store_merging::execute (function *fun)
 				       &unsignedp, &reversep, &volatilep);
 	      /* As a future enhancement we could handle stores with the same
 		 base and offset.  */
-	      bool invalid = offset || reversep
+	      bool invalid = offset || reversep || bitpos < 0
 			     || ((bitsize > MAX_BITSIZE_MODE_ANY_INT)
 				  && (TREE_CODE (rhs) != INTEGER_CST))
 			     || !rhs_valid_for_store_merging_p (rhs)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6827c0090bc..d979a56fcf7 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-11-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR tree-optimization/78162
+	* gcc.c-torture/compile/pr78162.c: New test.
+
 2016-11-02  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/78035
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr78162.c b/gcc/testsuite/gcc.c-torture/compile/pr78162.c
new file mode 100644
index 00000000000..743d4e678b5
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr78162.c
@@ -0,0 +1,10 @@
+/* PR tree-optimization/78162.
+   Handle negative offsets in store merging gracefully.  */
+
+int a, b[1][2];
+
+void fn1()
+{
+  for (a = 0; a < 2; a++)
+    b[-1][a] = 0;
+}