diff mbox series

Fix PR82276

Message ID alpine.LSU.2.20.1709211410160.26836@zhemvz.fhfr.qr
State New
Headers show
Series Fix PR82276 | expand

Commit Message

Richard Biener Sept. 21, 2017, 12:11 p.m. UTC 
The following fixes PR82276 and PR82244 in a slightly different way
to ensure VRP is able to fully propagate out asserts on abnormals to
restore valid SSA form.

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

Richard.

2017-09-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/82276
	PR tree-optimization/82244
	* tree-vrp.c (build_assert_expr_for): Set
	SSA_NAME_OCCURS_IN_ABNORMAL_PHI if the variable we assert on
	has it set.
	(remove_range_assertions): Revert earlier change.

	* gcc.dg/torture/pr82276.c: New testcase.
diff mbox series

Patch

Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c	(revision 253050)
+++ gcc/tree-vrp.c	(working copy)
@@ -4518,7 +4518,12 @@  build_assert_expr_for (tree cond, tree v
      operand of the ASSERT_EXPR.  Create it so the new name and the old one
      are registered in the replacement table so that we can fix the SSA web
      after adding all the ASSERT_EXPRs.  */
-  create_new_def_for (v, assertion, NULL);
+  tree new_def = create_new_def_for (v, assertion, NULL);
+  /* Make sure we preserve abnormalness throughout an ASSERT_EXPR chain
+     given we have to be able to fully propagate those out to re-create
+     valid SSA when removing the asserts.  */
+  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (v))
+    SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_def) = 1;
 
   return assertion;
 }
@@ -7039,14 +7044,6 @@  remove_range_assertions (void)
 		  FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 		    SET_USE (use_p, var);
 	      }
-	    /* But do not propagate constants as that is invalid.  */
-	    else if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
-	      {
-		gassign *ass = gimple_build_assign (lhs, var);
-		gsi_replace (&si, ass, true);
-		gsi_next (&si);
-		continue;
-	      }
 	    else
 	      replace_uses_by (lhs, var);
 
Index: gcc/testsuite/gcc.dg/torture/pr82276.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr82276.c	(revision 0)
+++ gcc/testsuite/gcc.dg/torture/pr82276.c	(working copy)
@@ -0,0 +1,32 @@ 
+/* { dg-do compile } */
+
+typedef struct a {
+  struct a *b;
+} a;
+
+extern int d(void);
+extern int g(void);
+extern int h(void);
+extern int _setjmp();
+extern int i(void);
+
+void c(void) {
+    1 ? d() : 0;
+    a *e;
+    while (e) {
+	e = (e == (a *) c) ? 0 : e->b;
+	while (e) {
+	    unsigned int f = 0;
+	    g();
+	    _setjmp(f);
+	    if (f & 6) {
+		;
+	    } else if (f & 2) {
+		;
+	    } else {
+		h();
+	    }
+	    i();
+	}
+    }
+}