re PR middle-end/91623 (-msse4.1 -O3 segfault in…

re PR middle-end/91623 (-msse4.1 -O3 segfault in /usr/lib/gcc/x86_64-pc-linux-gnu/8.3.0/include/smmintrin.h:270:10)

	PR middle-end/91623
	* optabs.c (expand_vec_cond_expr): If op0 is a VECTOR_CST and only
	EQ_EXPR/NE_EXPR is supported, verify that op0 only contains
	zeros or negative elements and use NE_EXPR instead of LT_EXPR against
	zero vector.

	* gcc.target/i386/pr91623.c: New test.

From-SVN: r275267

gcc/ChangeLog

 2019-09-01  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/91623
+	* optabs.c (expand_vec_cond_expr): If op0 is a VECTOR_CST and only
+	EQ_EXPR/NE_EXPR is supported, verify that op0 only contains
+	zeros or negative elements and use NE_EXPR instead of LT_EXPR against
+	zero vector.
+
 	PR lto/91572
 	* tree.c (find_decls_types_in_node): Also walk TREE_PURPOSE of
 	GIMPLE_ASM TREE_LIST operands.

gcc/optabs.c

@@ -5868,6 +5868,25 @@ expand_vec_cond_expr (tree vec_cond_type, tree op0, tree op1, tree op2,
   icode = get_vcond_icode (mode, cmp_op_mode, unsignedp);
   if (icode == CODE_FOR_nothing)
     {
+      if (tcode == LT_EXPR
+	  && op0a == op0
+	  && TREE_CODE (op0) == VECTOR_CST)
+	{
+	  /* A VEC_COND_EXPR condition could be folded from EQ_EXPR/NE_EXPR
+	     into a constant when only get_vcond_eq_icode is supported.
+	     Verify < 0 and != 0 behave the same and change it to NE_EXPR.  */
+	  unsigned HOST_WIDE_INT nelts;
+	  if (!VECTOR_CST_NELTS (op0).is_constant (&nelts))
+	    {
+	      if (VECTOR_CST_STEPPED_P (op0))
+		return 0;
+	      nelts = vector_cst_encoded_nelts (op0);
+	    }
+	  for (unsigned int i = 0; i < nelts; ++i)
+	    if (tree_int_cst_sgn (vector_cst_elt (op0, i)) == 1)
+	      return 0;
+	  tcode = NE_EXPR;
+	}
       if (tcode == EQ_EXPR || tcode == NE_EXPR)
 	icode = get_vcond_eq_icode (mode, cmp_op_mode);
       if (icode == CODE_FOR_nothing)

gcc/testsuite/ChangeLog

 2019-09-01  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/91623
+	* gcc.target/i386/pr91623.c: New test.
+
 	PR lto/91572
 	* g++.dg/lto/pr91572_0.C: New test.
 

gcc/testsuite/gcc.target/i386/pr91623.c

+/* PR middle-end/91623 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -msse4.1 -mno-sse4.2" } */
+
+typedef long long V __attribute__((__vector_size__(16)));
+V e, h;
+int d;
+const int i;
+
+void foo (void);
+
+void
+bar (int k, int l)
+{
+  if (d && 0 <= k - 1 && l)
+    foo ();
+}
+
+void
+baz (void)
+{
+  V n = (V) { 1 };
+  V g = (V) {};
+  V o = g;
+  for (int f = 0; f < i; ++f)
+    {
+      V a = o == n;
+      h = a;
+      bar (f, i);
+      o = e;
+    }
+}