From: Richard Biener <rguenther@suse.de>
Date: Mon, 12 Jul 2021 08:49:03 +0000 (+0200)
Subject: tree-optimization/101394 - fix PRE full redundancy wrt abnormals
X-Git-Tag: basepoints/gcc-13~6069
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=92343e0ba4d47f21ae20ffcb83d736bdbc15dae0;p=thirdparty%2Fgcc.git

tree-optimization/101394 - fix PRE full redundancy wrt abnormals

This avoids adding a copy from an abnormal picked up from PHI
translation much like we'd avoid inserting the translated
expression on pred edges.

2021-07-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/101394
	* tree-ssa-pre.c (do_pre_regular_insertion): Avoid inserting
	copies from abnormals for a full redundancy.

	* gcc.dg/torture/pr101394.c: New testcase.
---

diff --git a/gcc/testsuite/gcc.dg/torture/pr101394.c b/gcc/testsuite/gcc.dg/torture/pr101394.c
new file mode 100644
index 000000000000..87fbdadc1525
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr101394.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+
+int a, b, c, d;
+void h();
+int e() __attribute__((returns_twice));
+void f() {
+  int *g = (int *)(__INTPTR_TYPE__)c;
+  if (b) {
+    h();
+    g--;
+    if (a)
+      if (d)
+        h();
+  }
+  if (g++)
+    e();
+  c = (__INTPTR_TYPE__)g;
+}
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index d86fe26bd07f..69141c2f0c92 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -3412,7 +3412,11 @@ do_pre_regular_insertion (basic_block block, basic_block dom,
 	  /* If all edges produce the same value and that value is
 	     an invariant, then the PHI has the same value on all
 	     edges.  Note this.  */
-	  else if (!cant_insert && all_same)
+	  else if (!cant_insert
+		   && all_same
+		   && (edoubleprime->kind != NAME
+		       || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI
+			     (PRE_EXPR_NAME (edoubleprime))))
 	    {
 	      gcc_assert (edoubleprime->kind == CONSTANT
 			  || edoubleprime->kind == NAME);