On Mon, 1 Dec 2014, Richard Biener wrote:
The following fixes PR64126.Bootstrapped and tested on x86_64-unknown-linux-gnu, applied. Richard. 2014-12-01 Richard Biener <rguent...@suse.de> PR middle-end/64126 * match.pd: Allow conversions in ~A + 1 -> -A, add -A - 1 -> ~A and -1 - A -> ~A. * fold-const.c (fold_binary_loc): Remove transforms here. Index: gcc/match.pd =================================================================== --- gcc/match.pd (revision 218144) +++ gcc/match.pd (working copy) @@ -484,8 +522,22 @@ (define_operator_list inverted_tcc_compa /* ~A + 1 -> -A */ (simplify - (plus (bit_not @0) integer_each_onep) - (negate @0)) + (plus (convert? (bit_not @0)) integer_each_onep) + (if (tree_nop_conversion_p (type, TREE_TYPE (@0))) + (negate (convert @0)))) + + /* -A - 1 -> ~A */ + (simplify + (minus (convert? (negate @0)) integer_each_onep) + (if (!TYPE_OVERFLOW_TRAPS (type)
I don't understand why TYPE_OVERFLOW_TRAPS is tested for this one but not the others.
+ && tree_nop_conversion_p (type, TREE_TYPE (@0))) + (bit_not (convert @0)))) + + /* -1 - A -> ~A */ + (simplify + (minus integer_all_onesp @0) + (if (TREE_CODE (type) != COMPLEX_TYPE) + (bit_not @0)))
It should also be true for COMPLEX_TYPE where integer_all_onesp tests for -1-i.
(I know you are just copying from fold-const) -- Marc Glisse
