From: Richard Biener <rguenther@suse.de>
Date: Wed, 16 Sep 2015 07:25:15 +0000 (+0000)
Subject: re PR middle-end/67442 (GCC 5.2.0 on x86_64 creates invalid address on specific array... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=87261d26850e695a2e68f1e7b6115001ee67299e;p=gcc.git

re PR middle-end/67442 (GCC 5.2.0 on x86_64 creates invalid address on specific array index calculation through pointer)

2015-09-16  Richard Biener  <rguenther@suse.de>

	PR middle-end/67442
	* fold-const.c (extract_muldiv_1): Properly extend multiplication
	result before builting a tree via wide_int_to_tree.

	* gcc.dg/torture/pr67442.c: New testcase.

From-SVN: r227818
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 92ed286935c..fca25b9b867 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-09-16  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/67442
+	* fold-const.c (extract_muldiv_1): Properly extend multiplication
+	result before builting a tree via wide_int_to_tree.
+
 2015-09-16  Mikhail Maltsev  <maltsevm@gmail.com>
 
 	* Makefile.in: Add memory-block.cc
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index e9366e2de6e..fd1c87ed5ad 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -6166,8 +6166,12 @@ extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
 	      && ((sign == UNSIGNED && tcode != MULT_EXPR) || sign == SIGNED))
 	    overflow_p = true;
 	  if (!overflow_p)
-	    return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
-				wide_int_to_tree (ctype, mul));
+	    {
+	      mul = wide_int::from (mul, TYPE_PRECISION (ctype),
+				    TYPE_SIGN (TREE_TYPE (op1)));
+	      return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
+				  wide_int_to_tree (ctype, mul));
+	    }
 	}
 
       /* If these operations "cancel" each other, we have the main
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b4eaf3de35d..9035db974d0 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-09-16  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/67442
+	* gcc.dg/torture/pr67442.c: New testcase.
+
 2015-09-15  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/array24.adb: New test.
diff --git a/gcc/testsuite/gcc.dg/torture/pr67442.c b/gcc/testsuite/gcc.dg/torture/pr67442.c
new file mode 100644
index 00000000000..bc214d62d4d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr67442.c
@@ -0,0 +1,12 @@
+/* { dg-do run } */
+
+short foo[100];
+
+int main()
+{
+  short* bar = &foo[50];
+  short i = 1;
+  short j = 1;
+  short value = bar[8 - i * 2 * j];
+  return value;
+}