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author | Jakub Jelinek <jakub@redhat.com> | 2023-05-21 13:36:56 +0200 |
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committer | Jakub Jelinek <jakub@redhat.com> | 2023-05-21 13:36:56 +0200 |
commit | f211757f6fa9515e3fd1a4f66f1a8b48e500c9de (patch) | |
tree | c0dcf24b10972c6e7d046b96bb418b1556ede9fa /gcc | |
parent | 7f3df8e65c71e5df01fe7fe7de577bb9ff48f37b (diff) | |
download | gcc-f211757f6fa9515e3fd1a4f66f1a8b48e500c9de.zip gcc-f211757f6fa9515e3fd1a4f66f1a8b48e500c9de.tar.gz gcc-f211757f6fa9515e3fd1a4f66f1a8b48e500c9de.tar.bz2 |
atch.pd: Ensure (op CONSTANT_CLASS_P CONSTANT_CLASS_P) is simplified [PR109505]
On the following testcase we hang, because POLY_INT_CST is CONSTANT_CLASS_P,
but BIT_AND_EXPR with it and INTEGER_CST doesn't simplify and the
(x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2)
simplification actually relies on the (CST1 & CST2) simplification,
otherwise it is a deoptimization, trading 2 ops for 3 and furthermore
running into
/* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
operands are another bit-wise operation with a common input. If so,
distribute the bit operations to save an operation and possibly two if
constants are involved. For example, convert
(A | B) & (A | C) into A | (B & C)
Further simplification will occur if B and C are constants. */
simplification which simplifies that
(x & CST2) | (CST1 & CST2) back to
CST2 & (x | CST1).
I went through all other places I could find where we have a simplification
with 2 CONSTANT_CLASS_P operands and perform some operation on those two,
while the other spots aren't that severe (just trade 2 operations for
another 2 if the two constants don't simplify, rather than as in the above
case trading 2 ops for 3), I still think all those spots really intend
to optimize only if the 2 constants simplify.
So, the following patch adds to those a ! modifier to ensure that,
even at GENERIC that modifier means !EXPR_P which is exactly what we want
IMHO.
2023-05-21 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/109505
* match.pd ((x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2),
Combine successive equal operations with constants,
(A +- CST1) +- CST2 -> A + CST3, (CST1 - A) +- CST2 -> CST3 - A,
CST1 - (CST2 - A) -> CST3 + A): Use ! on ops with 2 CONSTANT_CLASS_P
operands.
* gcc.target/aarch64/sve/pr109505.c: New test.
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/match.pd | 20 | ||||
-rw-r--r-- | gcc/testsuite/gcc.target/aarch64/sve/pr109505.c | 12 |
2 files changed, 22 insertions, 10 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 30ffdfc..1fe0559 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1916,7 +1916,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* (x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2) */ (simplify (bit_and (bit_ior @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2) - (bit_ior (bit_and @0 @2) (bit_and @1 @2))) + (bit_ior (bit_and @0 @2) (bit_and! @1 @2))) /* Combine successive equal operations with constants. */ (for bitop (bit_and bit_ior bit_xor) @@ -1925,7 +1925,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (if (!CONSTANT_CLASS_P (@0)) /* This is the canonical form regardless of whether (bitop @1 @2) can be folded to a constant. */ - (bitop @0 (bitop @1 @2)) + (bitop @0 (bitop! @1 @2)) /* In this case we have three constants and (bitop @0 @1) doesn't fold to a constant. This can happen if @0 or @1 is a POLY_INT_CST and if the values involved are such that the operation can't be decided at @@ -2998,13 +2998,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) forever if something doesn't simplify into a constant. */ (if (!CONSTANT_CLASS_P (@0)) (if (outer_op == PLUS_EXPR) - (plus (view_convert @0) (inner_op @2 (view_convert @1))) - (minus (view_convert @0) (neg_inner_op @2 (view_convert @1))))) + (plus (view_convert @0) (inner_op! @2 (view_convert @1))) + (minus (view_convert @0) (neg_inner_op! @2 (view_convert @1))))) (if (!ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0)) || TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))) (if (outer_op == PLUS_EXPR) - (view_convert (plus @0 (inner_op (view_convert @2) @1))) - (view_convert (minus @0 (neg_inner_op (view_convert @2) @1)))) + (view_convert (plus @0 (inner_op! (view_convert @2) @1))) + (view_convert (minus @0 (neg_inner_op! (view_convert @2) @1)))) /* If the constant operation overflows we cannot do the transform directly as we would introduce undefined overflow, for example with (a - 1) + INT_MIN. */ @@ -3035,10 +3035,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* If all 3 captures are CONSTANT_CLASS_P, punt, as we might recurse forever if something doesn't simplify into a constant. */ (if (!CONSTANT_CLASS_P (@0)) - (minus (outer_op (view_convert @1) @2) (view_convert @0))) + (minus (outer_op! (view_convert @1) @2) (view_convert @0))) (if (!ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0)) || TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))) - (view_convert (minus (outer_op @1 (view_convert @2)) @0)) + (view_convert (minus (outer_op! @1 (view_convert @2)) @0)) (if (types_match (type, @0) && !TYPE_OVERFLOW_SANITIZED (type)) (with { tree cst = const_binop (outer_op, type, @1, @2); } (if (cst && !TREE_OVERFLOW (cst)) @@ -3054,10 +3054,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* If all 3 captures are CONSTANT_CLASS_P, punt, as we might recurse forever if something doesn't simplify into a constant. */ (if (!CONSTANT_CLASS_P (@0)) - (plus (view_convert @0) (minus @1 (view_convert @2)))) + (plus (view_convert @0) (minus! @1 (view_convert @2)))) (if (!ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0)) || TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))) - (view_convert (plus @0 (minus (view_convert @1) @2))) + (view_convert (plus @0 (minus! (view_convert @1) @2))) (if (types_match (type, @0) && !TYPE_OVERFLOW_SANITIZED (type)) (with { tree cst = const_binop (MINUS_EXPR, type, @1, @2); } (if (cst && !TREE_OVERFLOW (cst)) diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pr109505.c b/gcc/testsuite/gcc.target/aarch64/sve/pr109505.c new file mode 100644 index 0000000..b975ae7 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/sve/pr109505.c @@ -0,0 +1,12 @@ +/* PR tree-optimization/109505 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -march=armv8.2-a+sve" } */ + +#pragma GCC aarch64 "arm_sve.h" + +unsigned long +foo (unsigned long x) +{ + unsigned long y = svcntb (); + return (x | 15) & y; +} |