https://gcc.gnu.org/g:547143df5aa0960fb149a26933dad7ca1c363afb
commit r15-908-g547143df5aa0960fb149a26933dad7ca1c363afb
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date: Sun May 26 17:38:37 2024 -0700
match: Add support for `a ^ CST` to bitwise_inverted_equal_p [PR115224]
While looking into something else, I noticed that `a ^ CST` needed to be
special casing to bitwise_inverted_equal_p as it would simplify to `a ^
~CST`
for the bitwise not.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/115224
gcc/ChangeLog:
* generic-match-head.cc (bitwise_inverted_equal_p): Add `a ^ CST`
case.
* gimple-match-head.cc (gimple_bit_xor_cst): New declaration.
(gimple_bitwise_inverted_equal_p): Add `a ^ CST` case.
* match.pd (bit_xor_cst): New match.
(maybe_bit_not): Add bit_xor_cst case.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/bitops-8.c: New test.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
Diff:
---
gcc/generic-match-head.cc | 10 ++++++++++
gcc/gimple-match-head.cc | 13 +++++++++++++
gcc/match.pd | 4 ++++
gcc/testsuite/gcc.dg/tree-ssa/bitops-8.c | 15 +++++++++++++++
4 files changed, 42 insertions(+)
diff --git a/gcc/generic-match-head.cc b/gcc/generic-match-head.cc
index 55ba369c6b3..641d8e9b2de 100644
--- a/gcc/generic-match-head.cc
+++ b/gcc/generic-match-head.cc
@@ -158,6 +158,16 @@ bitwise_inverted_equal_p (tree expr1, tree expr2, bool
&wascmp)
if (TREE_CODE (expr2) == BIT_NOT_EXPR
&& bitwise_equal_p (expr1, TREE_OPERAND (expr2, 0)))
return true;
+
+ /* `X ^ CST` and `X ^ ~CST` match for ~. */
+ if (TREE_CODE (expr1) == BIT_XOR_EXPR && TREE_CODE (expr2) == BIT_XOR_EXPR
+ && bitwise_equal_p (TREE_OPERAND (expr1, 0), TREE_OPERAND (expr2, 0)))
+ {
+ tree cst1 = uniform_integer_cst_p (TREE_OPERAND (expr1, 1));
+ tree cst2 = uniform_integer_cst_p (TREE_OPERAND (expr2, 1));
+ if (cst1 && cst2 && wi::to_wide (cst1) == ~wi::to_wide (cst2))
+ return true;
+ }
if (COMPARISON_CLASS_P (expr1)
&& COMPARISON_CLASS_P (expr2))
{
diff --git a/gcc/gimple-match-head.cc b/gcc/gimple-match-head.cc
index 6220725b259..e26fa0860ee 100644
--- a/gcc/gimple-match-head.cc
+++ b/gcc/gimple-match-head.cc
@@ -283,6 +283,7 @@ gimple_bitwise_equal_p (tree expr1, tree expr2, tree
(*valueize) (tree))
bool gimple_bit_not_with_nop (tree, tree *, tree (*) (tree));
bool gimple_maybe_cmp (tree, tree *, tree (*) (tree));
+bool gimple_bit_xor_cst (tree, tree *, tree (*) (tree));
/* Helper function for bitwise_inverted_equal_p macro. */
@@ -301,6 +302,18 @@ gimple_bitwise_inverted_equal_p (tree expr1, tree expr2,
bool &wascmp, tree (*va
if (operand_equal_p (expr1, expr2, 0))
return false;
+ tree xor1[2];
+ tree xor2[2];
+ /* `X ^ CST` and `X ^ ~CST` match for ~. */
+ if (gimple_bit_xor_cst (expr1, xor1, valueize)
+ && gimple_bit_xor_cst (expr2, xor2, valueize))
+ {
+ if (operand_equal_p (xor1[0], xor2[0], 0)
+ && (wi::to_wide (uniform_integer_cst_p (xor1[1]))
+ == ~wi::to_wide (uniform_integer_cst_p (xor2[1]))))
+ return true;
+ }
+
tree other;
/* Try if EXPR1 was defined as ~EXPR2. */
if (gimple_bit_not_with_nop (expr1, &other, valueize))
diff --git a/gcc/match.pd b/gcc/match.pd
index 090ad4e08b0..480e36bbbaf 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -174,6 +174,8 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(match (bit_not_with_nop @0)
(convert (bit_not @0))
(if (tree_nop_conversion_p (type, TREE_TYPE (@0)))))
+(match (bit_xor_cst @0 @1)
+ (bit_xor @0 uniform_integer_cst_p@1))
(for cmp (tcc_comparison)
(match (maybe_cmp @0)
(cmp@0 @1 @2))
@@ -195,6 +197,8 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(INTEGER_CST@0))
(match (maybe_bit_not @0)
(maybe_cmp@0 @1))
+(match (maybe_bit_not @0)
+ (bit_xor_cst@0 @1 @2))
/* Transform likes of (char) ABS_EXPR <(int) x> into (char) ABSU_EXPR <x>
ABSU_EXPR returns unsigned absolute value of the operand and the operand
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bitops-8.c
b/gcc/testsuite/gcc.dg/tree-ssa/bitops-8.c
new file mode 100644
index 00000000000..40f756e4455
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bitops-8.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
+/* PR tree-optimization/115224 */
+
+int f1(int a, int b)
+{
+ a = a ^ 1;
+ int c = ~a;
+ return c | (a ^ b);
+ // ~((a ^ 1) & b) or (a ^ -2) | ~b
+}
+/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "bit_ior_expr, " 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "bit_not_expr, " 1 "optimized" } } */
+
