[gcc r12-5513] match.pd: Fix up the recent bitmask_inv_cst_vector_p simplification [PR103417]

[gcc r12-5513] match.pd: Fix up the recent bitmask_inv_cst_vector_p simplification [PR103417]

[Jakub Jelinek]

https://gcc.gnu.org/g:94912212d3d1be0b1c490e9b5f45165ef5f30d8a

commit r12-5513-g94912212d3d1be0b1c490e9b5f45165ef5f30d8a
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Nov 25 10:47:24 2021 +0100

    match.pd: Fix up the recent bitmask_inv_cst_vector_p simplification [PR103417]
    
    The following testcase is miscompiled since the r12-5489-g0888d6bbe97e10
    changes.
    The simplification triggers on
    (x & 4294967040U) >= 0U
    and turns it into:
    x <= 255U
    which is incorrect, it should fold to 1 because unsigned >= 0U is always
    true and normally the
    /* Non-equality compare simplifications from fold_binary  */
         (if (wi::to_wide (cst) == min)
           (if (cmp == GE_EXPR)
            { constant_boolean_node (true, type); })
    simplification folds that, but this simplification was done earlier.
    
    The simplification correctly doesn't include lt which has the same
    reason why it shouldn't be handled, we'll fold it to 0 elsewhere.
    
    But, IMNSHO while it isn't incorrect to handle le and gt there, it is
    unnecessary.  Because (x & cst) <= 0U and (x & cst) > 0U should
    never appear, again in
    /* Non-equality compare simplifications from fold_binary  */
    we have a simplification for it:
           (if (cmp == LE_EXPR)
            (eq @2 @1))
           (if (cmp == GT_EXPR)
            (ne @2 @1))))
    This is done for
      (cmp (convert?@2 @0) uniform_integer_cst_p@1)
    and so should be done for both integers and vectors.
    As the bitmask_inv_cst_vector_p simplification only handles
    eq and ne for signed types, I think it can be simplified to just
    following patch.
    
    2021-11-25  Jakub Jelinek  <jakub@redhat.com>
    
            PR tree-optimization/103417
            * match.pd ((X & Y) CMP 0): Only handle eq and ne.  Commonalize
            common tests.
    
            * gcc.c-torture/execute/pr103417.c: New test.

Diff:
---
 gcc/match.pd                                   | 22 +++++++++-------------
 gcc/testsuite/gcc.c-torture/execute/pr103417.c | 11 +++++++++++
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/gcc/match.pd b/gcc/match.pd
index 5adcd6bd02c..39fd77ddc4a 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5214,20 +5214,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 /* Transform comparisons of the form (X & Y) CMP 0 to X CMP2 Z
    where ~Y + 1 == pow2 and Z = ~Y.  */
 (for cst (VECTOR_CST INTEGER_CST)
- (for cmp (le eq ne ge gt)
-      icmp (le le gt le gt)
- (simplify
-  (cmp (bit_and:c@2 @0 cst@1) integer_zerop)
-   (with { tree csts = bitmask_inv_cst_vector_p (@1); }
-     (switch
-      (if (csts && TYPE_UNSIGNED (TREE_TYPE (@1))
-	   && (VECTOR_TYPE_P (TREE_TYPE (@1)) || single_use (@2)))
-       (icmp @0 { csts; }))
-      (if (csts && !TYPE_UNSIGNED (TREE_TYPE (@1))
-	   && (cmp == EQ_EXPR || cmp == NE_EXPR)
-	   && (VECTOR_TYPE_P (TREE_TYPE (@1)) || single_use (@2)))
+ (for cmp (eq ne)
+      icmp (le gt)
+  (simplify
+   (cmp (bit_and:c@2 @0 cst@1) integer_zerop)
+    (with { tree csts = bitmask_inv_cst_vector_p (@1); }
+     (if (csts && (VECTOR_TYPE_P (TREE_TYPE (@1)) || single_use (@2)))
+      (if (TYPE_UNSIGNED (TREE_TYPE (@1)))
+       (icmp @0 { csts; })
        (with { tree utype = unsigned_type_for (TREE_TYPE (@1)); }
-	(icmp (convert:utype @0) { csts; }))))))))
+	 (icmp (convert:utype @0) { csts; }))))))))
 
 /* -A CMP -B -> B CMP A.  */
 (for cmp (tcc_comparison)
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr103417.c b/gcc/testsuite/gcc.c-torture/execute/pr103417.c
new file mode 100644
index 00000000000..0fef8908036
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr103417.c
@@ -0,0 +1,11 @@
+/* PR tree-optimization/103417 */
+
+struct { int a : 8; int b : 24; } c = { 0, 1 };
+
+int
+main ()
+{
+  if (c.b && !c.b)
+    __builtin_abort ();
+  return 0;
+}