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Re: [PATCH] Fix PR64126
- From: Marc Glisse <marc dot glisse at inria dot fr>
- To: Richard Biener <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 1 Dec 2014 22:20:36 +0100 (CET)
- Subject: Re: [PATCH] Fix PR64126
- Authentication-results: sourceware.org; auth=none
- References: <alpine dot LSU dot 2 dot 11 dot 1412011400000 dot 5894 at zhemvz dot fhfr dot qr>
- Reply-to: gcc-patches at gcc dot gnu dot org
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 <rguenther@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