[PATCH] tree-optimization/116057 - wrong code with CCP and vector CTORs

[Richard Biener]

The following fixes an issue with CCPs likely_value when faced with
a vector CTOR containing undef SSA names and constants.  This should
be classified as CONSTANT and not UNDEFINED.

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

        PR tree-optimization/116057
        * tree-ssa-ccp.cc (likely_value): Also walk CTORs in stmt
        operands to look for constants.

        * gcc.dg/torture/pr116057.c: New testcase.
---
 gcc/testsuite/gcc.dg/torture/pr116057.c | 20 ++++++++++++++++++++
 gcc/tree-ssa-ccp.cc                     | 11 +++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr116057.c

diff --git a/gcc/testsuite/gcc.dg/torture/pr116057.c 
b/gcc/testsuite/gcc.dg/torture/pr116057.c
new file mode 100644
index 00000000000..a7021c8e746
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr116057.c
@@ -0,0 +1,20 @@
+/* { dg-do run } */
+/* { dg-additional-options "-Wno-psabi" } */
+
+#define vect8 __attribute__((vector_size(8)))
+
+vect8 int __attribute__((noipa))
+f(int a)
+{
+  int b;
+  vect8 int t={1,1};
+  if(a) return t;
+  return (vect8 int){0, b};
+}
+
+int main ()
+{
+  if (f(0)[0] != 0)
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssa-ccp.cc b/gcc/tree-ssa-ccp.cc
index de83d26d311..44711018e0e 100644
--- a/gcc/tree-ssa-ccp.cc
+++ b/gcc/tree-ssa-ccp.cc
@@ -762,6 +762,17 @@ likely_value (gimple *stmt)
        continue;
       if (is_gimple_min_invariant (op))
        has_constant_operand = true;
+      else if (TREE_CODE (op) == CONSTRUCTOR)
+       {
+         unsigned j;
+         tree val;
+         FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (op), j, val)
+           if (CONSTANT_CLASS_P (val))
+             {
+               has_constant_operand = true;
+               break;
+             }
+       }
     }
 
   if (has_constant_operand)
-- 
2.35.3