Hi!
My relatively recent changes to these simplifiers to avoid
doing build_nonstandard_integer_type (primarily for BITINT_TYPE)
broke PR111668, a recurrence of the PR110487 bug.
I thought the build_nonstandard_integer_type isn't ever needed there,
but there is one special case where it is.
For the a ? -1 : 0 and a ? 0 : -1 simplifications there are actually
3 different cases. One is for signed 1-bit precision types (signed
kind of implied from integer_all_onesp, because otherwise it would
match integer_onep earlier), where the simplifier wierdly was matching
them using the a ? powerof2cst : 0 -> a << (log2(powerof2cst))
simplification and then another simplifier optimizing away the left shift
when log2(powerof2cst) was 0. Another one is signed BOOLEAN_TYPE with
precision > 1, where indeed we shouldn't be doing the negation in type,
because it isn't well defined in that type, the type only has 2 valid
values, 0 and -1. As an alternative, we could also e.g. cast to
signed 1-bit precision BOOLEAN_TYPE and then extend to type.
And the last case is what we were doing for types which have both 1 and -1
(all all ones) as valid values (i.e. all signed/unsigned ENUMERAL_TYPEs,
INTEGRAL_TYPEs and BITINT_TYPEs with precision > 1).
The following patch avoids the hops through << 0 for 1-bit precision
and uses build_nonstandard_integer_type solely for the BOOLEAN_TYPE types
(where we have a guarantee the precision is reasonably small, nothing ought
to be created 129+ bit precision BOOLEAN_TYPEs).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2023-10-03 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/111668
* match.pd (a ? CST1 : CST2): Handle the a ? -1 : 0 and
a ? 0 : -1 cases before the powerof2cst cases and differentiate
between 1-bit precision types, larger precision boolean types
and other integral types. Fix comment pastos and formatting.
--- gcc/match.pd.jj 2023-10-02 09:42:01.657836005 +0200
+++ gcc/match.pd 2023-10-03 10:33:30.817614648 +0200
@@ -5100,36 +5100,53 @@ (define_operator_list SYNC_FETCH_AND_AND
(switch
(if (integer_zerop (@2))
(switch
- /* a ? 1 : 0 -> a if 0 and 1 are integral types. */
+ /* a ? 1 : 0 -> a if 0 and 1 are integral types. */
(if (integer_onep (@1))
(convert (convert:boolean_type_node @0)))
+ /* a ? -1 : 0 -> -a. */
+ (if (INTEGRAL_TYPE_P (type) && integer_all_onesp (@1))
+ (if (TYPE_PRECISION (type) == 1)
+ /* For signed 1-bit precision just cast bool to the type. */
+ (convert (convert:boolean_type_node @0))
+ (if (TREE_CODE (type) == BOOLEAN_TYPE)
+ (with {
+ tree intt = build_nonstandard_integer_type (TYPE_PRECISION (type),
+ TYPE_UNSIGNED (type));
+ }
+ (convert (negate (convert:intt (convert:boolean_type_node @0)))))
+ (negate (convert:type (convert:boolean_type_node @0))))))
/* a ? powerof2cst : 0 -> a << (log2(powerof2cst)) */
(if (INTEGRAL_TYPE_P (type) && integer_pow2p (@1))
(with {
tree shift = build_int_cst (integer_type_node, tree_log2 (@1));
}
- (lshift (convert (convert:boolean_type_node @0)) { shift; })))
- /* a ? -1 : 0 -> -a. No need to check the TYPE_PRECISION not being 1
- here as the powerof2cst case above will handle that case correctly. */
- (if (INTEGRAL_TYPE_P (type) && integer_all_onesp (@1))
- (negate (convert:type (convert:boolean_type_node @0))))))
+ (lshift (convert (convert:boolean_type_node @0)) { shift; })))))
(if (integer_zerop (@1))
(switch
- /* a ? 0 : 1 -> !a. */
+ /* a ? 0 : 1 -> !a. */
(if (integer_onep (@2))
(convert (bit_xor (convert:boolean_type_node @0) { boolean_true_node; })))
- /* a ? powerof2cst : 0 -> (!a) << (log2(powerof2cst)) */
+ /* a ? 0 : -1 -> -(!a). */
+ (if (INTEGRAL_TYPE_P (type) && integer_all_onesp (@2))
+ (if (TYPE_PRECISION (type) == 1)
+ /* For signed 1-bit precision just cast bool to the type. */
+ (convert (bit_xor (convert:boolean_type_node @0) { boolean_true_node; }))
+ (if (TREE_CODE (type) == BOOLEAN_TYPE)
+ (with {
+ tree intt = build_nonstandard_integer_type (TYPE_PRECISION (type),
+ TYPE_UNSIGNED (type));
+ }
+ (convert (negate (convert:intt (bit_xor (convert:boolean_type_node @0)
+ { boolean_true_node; })))))
+ (negate (convert:type (bit_xor (convert:boolean_type_node @0)
+ { boolean_true_node; }))))))
+ /* a ? 0 : powerof2cst -> (!a) << (log2(powerof2cst)) */
(if (INTEGRAL_TYPE_P (type) && integer_pow2p (@2))
(with {
tree shift = build_int_cst (integer_type_node, tree_log2 (@2));
}
(lshift (convert (bit_xor (convert:boolean_type_node @0)
- { boolean_true_node; })) { shift; })))
- /* a ? -1 : 0 -> -(!a). No need to check the TYPE_PRECISION not being 1
- here as the powerof2cst case above will handle that case correctly. */
- (if (INTEGRAL_TYPE_P (type) && integer_all_onesp (@2))
- (negate (convert:type (bit_xor (convert:boolean_type_node @0)
- { boolean_true_node; }))))))))
+ { boolean_true_node; })) { shift; })))))))
/* (a > 1) ? 0 : (cast)a is the same as (cast)(a == 1)
for unsigned types. */
Jakub
