re PR tree-optimization/80181 (ICE in set_lattice_value, at tree-ssa-ccp.c:505)

2017-03-27  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/80181
	* tree-ssa-ccp.c (likely_value): UNDEFINED ^ X is UNDEFINED.

	* gcc.dg/torture/pr80181.c: New testcase.

From-SVN: r246500

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6296cdd33de39cbe7ee6e08e3f7955bc51cbdb8e..600d26476b88bcd2a18b31d884badcc719f5021f 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-03-27  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/80181
+       * tree-ssa-ccp.c (likely_value): UNDEFINED ^ X is UNDEFINED.
+
 2017-03-27  Claudiu Zissulescu  <claziss@synopsys.com>
 
        * config/arc/predicates.md (move_double_src_operand): Replace the

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 184ccdb4712171805348e2c6ba39d98590bcb98d..bc302a8f7578ffd2211788536b3d46b97e271261 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-03-27  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/80181
+       * gcc.dg/torture/pr80181.c: New testcase.
+
 2017-03-27  Claudiu Zissulescu  <claziss@synopsys.com>
 
        * testsuite/gcc.target/arc/interrupt-4.c: New file.

diff --git a/gcc/testsuite/gcc.dg/torture/pr80181.c b/gcc/testsuite/gcc.dg/torture/pr80181.c
new file mode 100644 (file)
index 0000000..896ca4f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr80181.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+
+int
+nr (void)
+{
+}
+
+void
+it (int dl)
+{
+  int vp = 0;
+
+  for (;;)
+    {
+      dl = vp ^ nr ();
+      dl ^= vp;
+      vp = 1;
+    }
+}

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index cd238242c015f08a00958e3d1147f95070a28007..023018c8d333bc2a43f25ea27b183613fc50cb88 100644 (file)
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -741,9 +741,11 @@ likely_value (gimple *stmt)
        case PLUS_EXPR:
        case MINUS_EXPR:
        case POINTER_PLUS_EXPR:
+       case BIT_XOR_EXPR:
          /* Not MIN_EXPR, MAX_EXPR.  One VARYING operand may be selected.
             Not bitwise operators, one VARYING operand may specify the
-            result completely.  Not logical operators for the same reason.
+            result completely.
+            Not logical operators for the same reason, apart from XOR.
             Not COMPLEX_EXPR as one VARYING operand makes the result partly
             not UNDEFINED.  Not *DIV_EXPR, comparisons and shifts because
             the undefined operand may be promoted.  */