[PATCH] Match: Improve inverted_equal_p for bool and `^` and `==` [PR113186]
Andrew Pinski
quic_apinski@quicinc.com
Mon Jan 1 04:03:29 GMT 2024
For boolean types, `a ^ b` is a valid form for `a != b`. This means for
gimple_bitwise_inverted_equal_p, we catch some inverted value forms. This
patch extends inverted_equal_p to allow matching of `^` with the
corresponding `==`. Note in the testcase provided we used to optimize
in GCC 12 to just `return 0` where `a == b` was used,
this allows us to do that again.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimized/113186
gcc/ChangeLog:
* gimple-match-head.cc (gimple_bitwise_inverted_equal_p):
Match `^` with the `==` for 1bit integral types.
* match.pd (maybe_cmp): Allow for bit_xor for 1bit
integral types.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/bitops-bool-1.c: New test.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
---
gcc/gimple-match-head.cc | 20 ++++++++++++++++---
gcc/match.pd | 6 ++++++
gcc/testsuite/gcc.dg/tree-ssa/bitops-bool-1.c | 14 +++++++++++++
3 files changed, 37 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/bitops-bool-1.c
diff --git a/gcc/gimple-match-head.cc b/gcc/gimple-match-head.cc
index 322072332f9..56719154f59 100644
--- a/gcc/gimple-match-head.cc
+++ b/gcc/gimple-match-head.cc
@@ -333,9 +333,23 @@ gimple_bitwise_inverted_equal_p (tree expr1, tree expr2, bool &wascmp, tree (*va
if (!operand_equal_p (op11, op21))
return false;
wascmp = true;
- if (invert_tree_comparison (gimple_assign_rhs_code (a1),
- HONOR_NANS (op10))
- == gimple_assign_rhs_code (a2))
+ tree_code ac1 = gimple_assign_rhs_code (a1);
+ tree_code ac2 = gimple_assign_rhs_code (a2);
+ /* Match `^` against `==` but this should only
+ happen when the type is a 1bit precision integer. */
+ if (ac1 == BIT_XOR_EXPR)
+ {
+ tree type = TREE_TYPE (newexpr1);
+ gcc_assert (INTEGRAL_TYPE_P (type) && TYPE_PRECISION (type) == 1);
+ return ac2 == EQ_EXPR;
+ }
+ if (ac2 == BIT_XOR_EXPR)
+ {
+ tree type = TREE_TYPE (newexpr1);
+ gcc_assert (INTEGRAL_TYPE_P (type) && TYPE_PRECISION (type) == 1);
+ return ac1 == EQ_EXPR;
+ }
+ if (invert_tree_comparison (ac1, HONOR_NANS (op10)) == ac2)
return true;
return false;
}
diff --git a/gcc/match.pd b/gcc/match.pd
index a980c4d7e94..2392ffe5f30 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -182,6 +182,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(convert (cmp@0 @1 @2))
(if (tree_nop_conversion_p (type, TREE_TYPE (@0)))))
)
+/* `a ^ b` is another form of `a != b` when the type
+ is a 1bit precission integer. */
+(match (maybe_cmp @0)
+ (bit_xor@0 @1 @2)
+ (if (INTEGRAL_TYPE_P (type)
+ && TYPE_PRECISION (type) == 1)))
#endif
/* Transform likes of (char) ABS_EXPR <(int) x> into (char) ABSU_EXPR <x>
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bitops-bool-1.c b/gcc/testsuite/gcc.dg/tree-ssa/bitops-bool-1.c
new file mode 100644
index 00000000000..8b43afb5d66
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bitops-bool-1.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized -fdump-tree-forwprop1" } */
+/* PR tree-optimized/113186 */
+
+_Bool f(_Bool a, _Bool c)
+{
+ _Bool b = (a^c);
+ _Bool d = (a^!c);
+ return b & d;
+}
+
+/* This function should be optimized to return 0; */
+/* { dg-final { scan-tree-dump "return 0" "optimized" } } */
+/* { dg-final { scan-tree-dump "return 0" "forwprop1" } } */
--
2.39.3
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