re PR tree-optimization/36034 (wrong code vectorizing unrolled inner loop (SLP))

2008-04-24  Ira Rosen  <irar@il.ibm.com>
	Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/36034
	* tree-vect-analyze.c (vect_analyze_group_access): SLP is
	incapable of dealing with loads with gaps.

	* gcc.c-torture/execute/pr36034-1.c: New testcase.
	* gcc.c-torture/execute/pr36034-2.c: Likewise.

Co-Authored-By: Richard Guenther <rguenther@suse.de>

From-SVN: r134628

gcc/ChangeLog

+2008-04-24  Ira Rosen  <irar@il.ibm.com>
+	Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/36034
+	* tree-vect-analyze.c (vect_analyze_group_access): SLP is
+	incapable of dealing with loads with gaps.
+
 2008-04-24  Rafael Espindola  <espindola@google.com>
 
 	* tree-flow.h (vrp_evaluate_conditional): Change signature.

gcc/testsuite/ChangeLog

+2008-04-24  Ira Rosen  <irar@il.ibm.com>
+	Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/36034
+	* gcc.c-torture/execute/pr36034-1.c: New testcase.
+	* gcc.c-torture/execute/pr36034-2.c: Likewise.
+
 2008-04-24  Olivier Hainque  <hainque@adacore.com>
 
 	* gnat.dg/concat_length.adb: New test.

gcc/testsuite/gcc.c-torture/execute/pr36034-1.c

+double x[5][10] = { { 10, 11, 12, 13, 14, 15, -1, -1, -1, -1 },
+                    { 21, 22, 23, 24, 25, 26, -1, -1, -1, -1 },
+                    { 32, 33, 34, 35, 36, 37, -1, -1, -1, -1 },
+                    { 43, 44, 45, 46, 47, 48, -1, -1, -1, -1 },
+                    { 54, 55, 56, 57, 58, 59, -1, -1, -1, -1 } };
+double tmp[5][6];
+
+void __attribute__((noinline))
+test (void)
+{ 
+  int i, j;
+  for (i = 0; i < 5; ++i)
+    {
+      tmp[i][0] = x[i][0];
+      tmp[i][1] = x[i][1];
+      tmp[i][2] = x[i][2];
+      tmp[i][3] = x[i][3];
+      tmp[i][4] = x[i][4];
+      tmp[i][5] = x[i][5];
+    }
+}
+extern void abort (void);
+int main()
+{
+  int i, j;
+  test();
+  for (i = 0; i < 5; ++i)
+    for (j = 0; j < 6; ++j)
+      if (tmp[i][j] == -1)
+        abort ();
+  return 0;
+}

gcc/testsuite/gcc.c-torture/execute/pr36034-2.c

+double x[50] = { 10, 11, 12, 13, 14, 15, -1, -1, -1, -1,
+                 21, 22, 23, 24, 25, 26, -1, -1, -1, -1,
+                 32, 33, 34, 35, 36, 37, -1, -1, -1, -1,
+                 43, 44, 45, 46, 47, 48, -1, -1, -1, -1,
+                 54, 55, 56, 57, 58, 59, -1, -1, -1, -1 };
+double tmp[30];
+
+void __attribute__((noinline))
+test (void)
+{
+  int i, j;
+  for (i = 0; i < 5; ++i)
+    {
+      tmp[i*6] = x[i*10];
+      tmp[i*6+1] = x[i*10+1];
+      tmp[i*6+2] = x[i*10+2];
+      tmp[i*6+3] = x[i*10+3];
+      tmp[i*6+4] = x[i*10+4];
+      tmp[i*6+5] = x[i*10+5];
+    }
+}
+extern void abort (void);
+int main()
+{
+  int i, j;
+  test();
+  for (i = 0; i < 5; ++i)
+    for (j = 0; j < 6; ++j)
+      if (tmp[i*6+j] == -1)
+        abort ();
+  return 0;
+}

gcc/tree-vect-analyze.c

@@ -2228,11 +2228,16 @@ vect_analyze_group_access (struct data_reference *dr)
 
       /* Check that the size of the interleaving is equal to STEP for stores,
          i.e., that there are no gaps.  */
-      if (!DR_IS_READ (dr) && dr_step != count_in_bytes)
+      if (dr_step != count_in_bytes)
         {
-          if (vect_print_dump_info (REPORT_DETAILS))
-            fprintf (vect_dump, "interleaved store with gaps");
-          return false;
+          if (DR_IS_READ (dr))
+            slp_impossible = true;
+          else
+            {
+              if (vect_print_dump_info (REPORT_DETAILS))
+                fprintf (vect_dump, "interleaved store with gaps");
+              return false;
+            }
         }
 
       /* Check that STEP is a multiple of type size.  */