On Thu, Aug 24, 2023 at 9:16 PM Andrew Pinski via Gcc-patches
<[email protected]> wrote:
>
> In PR 106677, I noticed that on the trunk we were producing:
> ```
> _25 = SR.116_117 == 0;
> _27 = (unsigned char) _25;
> _32 = _27 | SR.116_117;
> ```
> From `SR.115_117 != 0 ? SR.115_117 : 1`
> Rather than:
> ```
> _119 = MAX_EXPR <1, SR.115_117>;
> ```
> Or (rather)
> ```
> _119 = SR.115_117 | 1;
> ```
> Due to the order of the patterns.
Hmm, that means the former when present in source isn't optimized?
> OK? Bootstrapped and tested on x86_64-linux-gnu with no
> regressions.
OK, but please add a comment indicating the ordering requirement.
Can you also add a testcase?
Richard.
> gcc/ChangeLog:
>
> * match.pd (`a ? one_zero : one_zero`): Move
> below detection of minmax.
> ---
> gcc/match.pd | 38 ++++++++++++++++++++------------------
> 1 file changed, 20 insertions(+), 18 deletions(-)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 890f050cbad..c87a0795667 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -4950,24 +4950,6 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> )
> )
>
> -(simplify
> - (cond @0 zero_one_valued_p@1 zero_one_valued_p@2)
> - (switch
> - /* bool0 ? bool1 : 0 -> bool0 & bool1 */
> - (if (integer_zerop (@2))
> - (bit_and (convert @0) @1))
> - /* bool0 ? 0 : bool2 -> (bool0^1) & bool2 */
> - (if (integer_zerop (@1))
> - (bit_and (bit_xor (convert @0) { build_one_cst (type); } ) @2))
> - /* bool0 ? 1 : bool2 -> bool0 | bool2 */
> - (if (integer_onep (@1))
> - (bit_ior (convert @0) @2))
> - /* bool0 ? bool1 : 1 -> (bool0^1) | bool1 */
> - (if (integer_onep (@2))
> - (bit_ior (bit_xor (convert @0) @2) @1))
> - )
> -)
> -
> /* Optimize
> # x_5 in range [cst1, cst2] where cst2 = cst1 + 1
> x_5 ? cstN ? cst4 : cst3
> @@ -5298,6 +5280,26 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> && integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, @3,
> @1)))
> (max @2 @4))))))
>
> +#if GIMPLE
> +(simplify
> + (cond @0 zero_one_valued_p@1 zero_one_valued_p@2)
> + (switch
> + /* bool0 ? bool1 : 0 -> bool0 & bool1 */
> + (if (integer_zerop (@2))
> + (bit_and (convert @0) @1))
> + /* bool0 ? 0 : bool2 -> (bool0^1) & bool2 */
> + (if (integer_zerop (@1))
> + (bit_and (bit_xor (convert @0) { build_one_cst (type); } ) @2))
> + /* bool0 ? 1 : bool2 -> bool0 | bool2 */
> + (if (integer_onep (@1))
> + (bit_ior (convert @0) @2))
> + /* bool0 ? bool1 : 1 -> (bool0^1) | bool1 */
> + (if (integer_onep (@2))
> + (bit_ior (bit_xor (convert @0) @2) @1))
> + )
> +)
> +#endif
> +
> /* X != C1 ? -X : C2 simplifies to -X when -C1 == C2. */
> (simplify
> (cond (ne @0 INTEGER_CST@1) (negate@3 @0) INTEGER_CST@2)
> --
> 2.31.1
>
