[PATCH] tree-optimization/110766 - missing PHI location check

[PATCH] tree-optimization/110766 - missing PHI location check

[Richard Biener]

The following adds a missing PHI location check before querying
the loop latch PHI arg from it.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

	PR tree-optimization/110766
	* tree-scalar-evolution.cc
	(analyze_and_compute_bitwise_induction_effect): Check the PHI
	is defined in the loop header.

	* gcc.dg/torture/pr110766.c: New testcase.
---
 gcc/testsuite/gcc.dg/torture/pr110766.c | 17 +++++++++++++++++
 gcc/tree-scalar-evolution.cc            |  1 +
 2 files changed, 18 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr110766.c

diff --git a/gcc/testsuite/gcc.dg/torture/pr110766.c b/gcc/testsuite/gcc.dg/torture/pr110766.c
new file mode 100644
index 00000000000..97dcacf1e00
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr110766.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+
+int a, b, c, e;
+short d, f;
+int g(int h) { return h > a ? h : h << a; }
+int main() {
+  while (e) {
+    b = 0;
+    for (; b < 3; b++)
+      if (c) {
+        e = g(1);
+        f = e | d;
+      }
+    d = 0;
+  }
+  return 0;
+}
diff --git a/gcc/tree-scalar-evolution.cc b/gcc/tree-scalar-evolution.cc
index 2abe8fa0b90..3fb6951e608 100644
--- a/gcc/tree-scalar-evolution.cc
+++ b/gcc/tree-scalar-evolution.cc
@@ -3519,6 +3519,7 @@ analyze_and_compute_bitwise_induction_effect (class loop* loop,
   if (!gimple_bitwise_induction_p (phidef, &match_op[0], NULL)
       || TREE_CODE (match_op[2]) != SSA_NAME
       || !(header_phi = dyn_cast <gphi *> (SSA_NAME_DEF_STMT (match_op[2])))
+      || gimple_bb (header_phi) != loop->header
       || gimple_phi_num_args (header_phi) != 2)
     return NULL_TREE;
 
-- 
2.35.3