middle-end/112740 - vector boolean CTOR expansion issue

The optimization to expand uniform boolean vectors by sign-extension
works only for dense masks but it failed to check that.

	PR middle-end/112740
	* expr.cc (store_constructor): Check the integer vector
	mask has a single bit per element before using sign-extension
	to expand an uniform vector.

	* gcc.dg/pr112740.c: New testcase.

diff --git a/gcc/expr.cc b/gcc/expr.cc
index dc816bc20fa4d59dd2bb5256b4142a5312f54c83..0bf80832fe50555a86b2406b4e2019bc992cb8df 100644 (file)
--- a/gcc/expr.cc
+++ b/gcc/expr.cc
@@ -7841,10 +7841,12 @@ store_constructor (tree exp, rtx target, int cleared, poly_int64 size,
            break;
          }
        /* Use sign-extension for uniform boolean vectors with
-          integer modes.  Effectively "vec_duplicate" for bitmasks.  */
-       if (!TREE_SIDE_EFFECTS (exp)
+          integer modes and single-bit mask entries.
+          Effectively "vec_duplicate" for bitmasks.  */
+       if (elt_size == 1
+           && !TREE_SIDE_EFFECTS (exp)
            && VECTOR_BOOLEAN_TYPE_P (type)
-           && SCALAR_INT_MODE_P (mode)
+           && SCALAR_INT_MODE_P (TYPE_MODE (type))
            && (elt = uniform_vector_p (exp))
            && !VECTOR_TYPE_P (TREE_TYPE (elt)))
          {

diff --git a/gcc/testsuite/gcc.dg/pr112740.c b/gcc/testsuite/gcc.dg/pr112740.c
new file mode 100644 (file)
index 0000000..8250caf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr112740.c
@@ -0,0 +1,19 @@
+/* { dg-do run { target { int128 } } } */
+/* { dg-options "" } */
+
+typedef unsigned __int128 __attribute__((__vector_size__ (16))) V;
+
+V
+foo (unsigned c, V v)
+{
+  return (V) (c <= v) == 0;
+}
+
+int
+main (void)
+{
+  V x = foo (0, (V) { });
+  if (x[0])
+    __builtin_abort ();
+  return 0;
+}