[C PATCH] Fix ICE with VEC_COND_EXPR and compound literals (PR c/70307)

[Marek Polacek]

This is another case where a C_MAYBE_CONST_EXPR leaks into the gimplifier.
Starting with r229128 and thus introduction of build_vec_cmp we now create
VEC_COND_EXPR when building a vector comparison.  The C_MAYBE_CONST_EXPR
originated in build_compound_literal when creating a COMPOUND_LITERAL_EXPR.
This is then made a part of op0 of a VEC_COND_EXPR.  But c_fully_fold_internal
doesn't know what to do with VEC_COND_EXPRs so the C_MAYBE_CONST_EXPR went
unnoticed into fold, oops.  The fix here is to teach c_fully_fold_internal
how to handle VEC_COND_EXPRs, which is what this patch attempts to do.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2016-04-01  Marek Polacek  <polacek@redhat.com>

	PR c/70307
	* c-fold.c (c_fully_fold_internal): Handle VEC_COND_EXPR.

	* gcc.dg/torture/pr70307.c: New test.

diff --git gcc/c/c-fold.c gcc/c/c-fold.c
index f07917f..d512824 100644
--- gcc/c/c-fold.c
+++ gcc/c/c-fold.c
@@ -528,6 +528,23 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands,
 	*maybe_const_itself &= op2_const_self;
       goto out;
 
+    case VEC_COND_EXPR:
+      orig_op0 = op0 = TREE_OPERAND (expr, 0);
+      op1 = TREE_OPERAND (expr, 1);
+      op2 = TREE_OPERAND (expr, 2);
+      op0 = c_fully_fold_internal (op0, in_init, maybe_const_operands,
+				   maybe_const_itself, for_int_const);
+      STRIP_TYPE_NOPS (op0);
+
+      /* OP1 will be a vector of -1 and OP2 a vector if 0, as created in
+	 build_vec_cmp -- no need to fold them.  */
+
+      if (op0 != orig_op0)
+	ret = fold_build3_loc (loc, code, TREE_TYPE (expr), op0, op1, op2);
+      else
+	ret = fold (expr);
+      goto out;
+
     case EXCESS_PRECISION_EXPR:
       /* Each case where an operand with excess precision may be
 	 encountered must remove the EXCESS_PRECISION_EXPR around
diff --git gcc/testsuite/gcc.dg/torture/pr70307.c gcc/testsuite/gcc.dg/torture/pr70307.c
index e69de29..d47c4b6 100644
--- gcc/testsuite/gcc.dg/torture/pr70307.c
+++ gcc/testsuite/gcc.dg/torture/pr70307.c
@@ -0,0 +1,62 @@
+/* PR c/70307 */
+/* { dg-do compile } */
+
+typedef int v4si __attribute__ ((vector_size (16)));
+
+v4si foo (v4si);
+
+v4si
+fn1 (int i)
+{
+  return i <= (v4si){(0, 0)};
+}
+
+v4si
+fn2 (int i)
+{
+  v4si r;
+  r = i <= (v4si){(0, 0)};
+  return r;
+}
+
+v4si
+fn3 (int i)
+{
+  return foo (i <= (v4si){(0, 0)});
+}
+
+v4si
+fn4 (int i)
+{
+  struct S { v4si v; };
+  struct S s = { .v = i <= (v4si){(0, 0)} };
+  return s.v;
+}
+
+v4si
+fn5 (int i)
+{
+  return (v4si){(1, i++)} == (v4si){(0, 0)};
+}
+
+v4si
+fn6 (int i)
+{
+  v4si r;
+  r = (v4si){(1, i++)} == (v4si){(0, 0)};
+  return r;
+}
+
+v4si
+fn7 (int i)
+{
+  return foo ((v4si){(1, i++)} == (v4si){(0, 0)});
+}
+
+v4si
+fn8 (int i)
+{
+  struct S { v4si v; };
+  struct S s = { .v = (v4si){(1, i++)} == (v4si){(0, 0)} };
+  return s.v;
+}

	Marek