fold-const: Fix division folding with vector operands [PR94412]

The following testcase is miscompiled since 4.9, we treat unsigned
vector types as if they were signed and "optimize" negations across it.

2020-03-31  Marc Glisse  <marc.glisse@inria.fr>
	    Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/94412
	* fold-const.c (fold_binary_loc) <case TRUNC_DIV_EXPR>: Use
	ANY_INTEGRAL_TYPE_P instead of INTEGRAL_TYPE_P.

	* gcc.c-torture/execute/pr94412.c: New test.

Co-authored-by: Marc Glisse <marc.glisse@inria.fr>

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e7ff9131f5d44cbaacc727076f7bf1df13af1229..4686c59f90c2198cc78f1c1a33eef3b160476c9b 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2020-03-31  Marc Glisse  <marc.glisse@inria.fr>
+           Jakub Jelinek  <jakub@redhat.com>
+
+       PR middle-end/94412
+       * fold-const.c (fold_binary_loc) <case TRUNC_DIV_EXPR>: Use
+       ANY_INTEGRAL_TYPE_P instead of INTEGRAL_TYPE_P.
+
 2020-03-31  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/94403

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 92679142f0472a46191e85b6fafed1c755a1b412..b79d059d7418c909db47f2d0976a89369c5536df 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -11148,11 +11148,11 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
 
       /* Convert -A / -B to A / B when the type is signed and overflow is
         undefined.  */
-      if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
+      if ((!ANY_INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
          && TREE_CODE (op0) == NEGATE_EXPR
          && negate_expr_p (op1))
        {
-         if (INTEGRAL_TYPE_P (type))
+         if (ANY_INTEGRAL_TYPE_P (type))
            fold_overflow_warning (("assuming signed overflow does not occur "
                                    "when distributing negation across "
                                    "division"),
@@ -11162,11 +11162,11 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
                                                    TREE_OPERAND (arg0, 0)),
                                  negate_expr (op1));
        }
-      if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
+      if ((!ANY_INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
          && TREE_CODE (arg1) == NEGATE_EXPR
          && negate_expr_p (op0))
        {
-         if (INTEGRAL_TYPE_P (type))
+         if (ANY_INTEGRAL_TYPE_P (type))
            fold_overflow_warning (("assuming signed overflow does not occur "
                                    "when distributing negation across "
                                    "division"),

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3f21cb321063af3e54a089ad182c113e1ca4cb36..32d5309882efb3664d006010d86c6c45f0f3cb87 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2020-03-31  Jakub Jelinek  <jakub@redhat.com>
 
+       PR middle-end/94412
+       * gcc.c-torture/execute/pr94412.c: New test.
+
        PR tree-optimization/94403
        * g++.dg/tree-ssa/pr94403.C: New test.
 

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr94412.c b/gcc/testsuite/gcc.c-torture/execute/pr94412.c
new file mode 100644 (file)
index 0000000..6c806bb
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr94412.c
@@ -0,0 +1,28 @@
+/* PR middle-end/94412 */
+
+typedef unsigned V __attribute__ ((__vector_size__ (sizeof (unsigned) * 2)));
+
+void
+foo (V *v, V *w)
+{
+  *w = -*v / 11;
+}
+
+void
+bar (V *v, V *w)
+{
+  *w = -18 / -*v;
+}
+
+int
+main ()
+{
+  V a = (V) { 1, 0 };
+  V b = (V) { 3, __INT_MAX__ };
+  V c, d;
+  foo (&a, &c);
+  bar (&b, &d);
+  if (c[0] != -1U / 11 || c[1] != 0 || d[0] != 0 || d[1] != -18U / -__INT_MAX__)
+    __builtin_abort ();
+  return 0;
+}