Fix PR83176

Message ID alpine.LSU.2.20.1801241033240.32271@zhemvz.fhfr.qr
State New
Headers show
Series
  • Fix PR83176
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Commit Message

Richard Biener Jan. 24, 2018, 9:35 a.m.
The following enhances chrec_fold_plus_1 to handle a case to avoid
ICEing during GRAPHITE code-gen.  It teaches us to handle
(signed T) { (T) x, +, y } + (signed T) z as
(signed T) ( { (T) x, +, y } + (T) (singed T) z ) instead of
failing with chrec_not_known.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2018-01-24  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/83176
	* tree-chrec.c (chrec_fold_plus_1): Handle (signed T){(T) .. }
	operands.

	* gcc.dg/graphite/pr83176.c: New testcase.

Patch

Index: gcc/tree-chrec.c
===================================================================
--- gcc/tree-chrec.c	(revision 256977)
+++ gcc/tree-chrec.c	(working copy)
@@ -295,8 +295,23 @@  chrec_fold_plus_1 (enum tree_code code,
 	  return chrec_fold_plus_poly_poly (code, type, op0, op1);
 
 	CASE_CONVERT:
-	  if (tree_contains_chrecs (op1, NULL))
-	    return chrec_dont_know;
+	  {
+	    /* We can strip sign-conversions to signed by performing the
+	       operation in unsigned.  */
+	    tree optype = TREE_TYPE (TREE_OPERAND (op1, 0));
+	    if (INTEGRAL_TYPE_P (type)
+		&& INTEGRAL_TYPE_P (optype)
+		&& tree_nop_conversion_p (type, optype)
+		&& TYPE_UNSIGNED (optype))
+	      return chrec_convert (type,
+				    chrec_fold_plus_1 (code, optype,
+						       chrec_convert (optype,
+								      op0, NULL),
+						       TREE_OPERAND (op1, 0)),
+				    NULL);
+	    if (tree_contains_chrecs (op1, NULL))
+	      return chrec_dont_know;
+	  }
 	  /* FALLTHRU */
 
 	default:
@@ -313,8 +328,23 @@  chrec_fold_plus_1 (enum tree_code code,
 	}
 
     CASE_CONVERT:
-      if (tree_contains_chrecs (op0, NULL))
-	return chrec_dont_know;
+      {
+	/* We can strip sign-conversions to signed by performing the
+	   operation in unsigned.  */
+	tree optype = TREE_TYPE (TREE_OPERAND (op0, 0));
+	if (INTEGRAL_TYPE_P (type)
+	    && INTEGRAL_TYPE_P (optype)
+	    && tree_nop_conversion_p (type, optype)
+	    && TYPE_UNSIGNED (optype))
+	  return chrec_convert (type,
+				chrec_fold_plus_1 (code, optype,
+						   TREE_OPERAND (op0, 0),
+						   chrec_convert (optype,
+								  op1, NULL)),
+				NULL);
+	if (tree_contains_chrecs (op0, NULL))
+	  return chrec_dont_know;
+      }
       /* FALLTHRU */
 
     default:
Index: gcc/testsuite/gcc.dg/graphite/pr83176.c
===================================================================
--- gcc/testsuite/gcc.dg/graphite/pr83176.c	(nonexistent)
+++ gcc/testsuite/gcc.dg/graphite/pr83176.c	(working copy)
@@ -0,0 +1,42 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -floop-nest-optimize" } */
+
+int wx, qi;
+
+void
+yj (int gw)
+{
+  int *ak = &gw;
+
+  while (wx != 0)
+    {
+      int k2 = (__INTPTR_TYPE__)&ak;
+      int **xq = (int **)&k2;
+
+ja:
+      *xq = &gw;
+
+      while (qi < 1)
+	{
+	  unsigned short int ey;
+
+be:
+	  for (ey = 0; ey < 251; ++ey)
+	    {
+	      for (wx = 0; wx < 2; ++wx)
+		{
+		}
+
+	      *ak += 8555712;
+	      k2 += *ak;
+	    }
+	  ++qi;
+	}
+    }
+
+  gw = 1;
+  if (gw != 0)
+    goto ja;
+  else
+    goto be;
+}