From: Richard Biener <rguenther@suse.de>
Date: Wed, 31 Jan 2018 13:07:53 +0000 (+0000)
Subject: re PR tree-optimization/84132 (tree-data-ref.c:3938: poor coding ?)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=957a25ab0c76a2beb268aad005804da41e136c37;p=gcc.git

re PR tree-optimization/84132 (tree-data-ref.c:3938: poor coding ?)

2018-01-31  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/84132
	* tree-data-ref.c (analyze_miv_subscript): Properly
	check whether evolution_function_is_affine_multivariate_p
	before calling gcd_of_steps_may_divide_p.

	* g++.dg/torture/pr84132.C: New testcase.

From-SVN: r257232
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8368986fbc8..b1e0891ba8c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2018-01-31  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/84132
+	* tree-data-ref.c (analyze_miv_subscript): Properly
+	check whether evolution_function_is_affine_multivariate_p
+	before calling gcd_of_steps_may_divide_p.
+
 2018-01-31  Julia Koval  <julia.koval@intel.com>
 
 	PR target/83618
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index eaa672beb24..e3f0c5aafcc 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-01-31  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/84132
+	* g++.dg/torture/pr84132.C: New testcase.
+
 2018-01-31  Jan Hubicka  <hubicka@ucw.cz>
 
 	* g++.dg/torture/pr81360.C: Drop unintended -O2 from dg-options and
diff --git a/gcc/testsuite/g++.dg/torture/pr84132.C b/gcc/testsuite/g++.dg/torture/pr84132.C
new file mode 100644
index 00000000000..205b8f63812
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr84132.C
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+
+struct g {
+    char b;
+    unsigned char *d[];
+} e;
+unsigned char f;
+void i()
+{
+  for (int h;; h++)
+    {
+      unsigned a = h;
+      for (int c = 0; c < 256; c += 6)
+	for (int h = c; h < c + 6; h++)
+	  e.d[h + a] = &f;
+    }
+}
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index e39067d7134..0b6ad5fd529 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -3976,9 +3976,8 @@ analyze_miv_subscript (tree chrec_a,
     }
 
   else if (evolution_function_is_constant_p (difference)
-	   /* For the moment, the following is verified:
-	      evolution_function_is_affine_multivariate_p (chrec_a,
-	      loop_nest->num) */
+	   && evolution_function_is_affine_multivariate_p (chrec_a,
+							   loop_nest->num)
 	   && !gcd_of_steps_may_divide_p (chrec_a, difference))
     {
       /* testsuite/.../ssa-chrec-33.c