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| author | Jakub Jelinek <jakub@redhat.com> | 2021-11-25 10:47:24 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2021-11-25 10:47:24 +0100 |
| commit | 94912212d3d1be0b1c490e9b5f45165ef5f30d8a (patch) | |
| tree | cdecb377c7d49fce020c30ea8ae0cbae21ddc765 /gcc | |
| parent | 531dae29a67e915a145d908bd2f46d22bc369c11 (diff) | |
| download | gcc-94912212d3d1be0b1c490e9b5f45165ef5f30d8a.zip gcc-94912212d3d1be0b1c490e9b5f45165ef5f30d8a.tar.gz gcc-94912212d3d1be0b1c490e9b5f45165ef5f30d8a.tar.bz2 | |
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.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/match.pd | 22 | ||||
| -rw-r--r-- | 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 5adcd6b..39fd77d 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 0000000..0fef890 --- /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; +} |