https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108688
--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:bcca64d70ce91e29717fb70cff252639df6902be commit r13-5758-gbcca64d70ce91e29717fb70cff252639df6902be Author: Jakub Jelinek <ja...@redhat.com> Date: Thu Feb 9 16:07:40 2023 +0100 match.pd: Simplify BFR of insert when extracting exactly all inserted bits [PR108688] On Thu, Feb 09, 2023 at 09:16:17AM +0100, Richard Biener via Gcc-patches wrote: > Hmm. Can we handle the case of the extraction exactly covering the > insertion separately then and simplify to plain @1? I was suggesting that in the PR. Here it is as an incremental patch on top of Andrew's patch. On the newly added testcase the ifcvt-folding difference without/with the incremental patch is: --- pr108688.c.171t.ifcvt_ 2023-02-09 10:47:30.169916845 +0100 +++ pr108688.c.171t.ifcvt 2023-02-09 10:48:44.942793453 +0100 @@ -25,6 +25,8 @@ Number of blocks in CFG: 11 Number of blocks to update: 5 ( 45%) +Applying pattern match.pd:7487, gimple-match.cc:243200 +Applying pattern match.pd:3987, gimple-match.cc:75423 Matching expression match.pd:1677, gimple-match.cc:209 Applying pattern match.pd:1733, gimple-match.cc:109481 Matching expression match.pd:2393, gimple-match.cc:852 @@ -70,7 +72,6 @@ void foo () signed char _29; <unnamed-signed:7> _30; unsigned int ivtmp_33; - <unnamed-signed:7> _ifc__35; unsigned char _ifc__37; unsigned char _ifc__38; unsigned char _ifc__39; @@ -91,8 +92,7 @@ void foo () _2 = (<unnamed-signed:7>) a.0_1; _ifc__38 = u.D.2741; _ifc__39 = BIT_INSERT_EXPR <_ifc__38, _2, 0 (7 bits)>; - _ifc__35 = BIT_FIELD_REF <_ifc__39, 7, 0>; - _4 = (signed char) _ifc__35; + _4 = (signed char) _2; b.1_5 = b; _6 = (signed char) b.1_5; _7 = _4 ^ _6; 2023-02-09 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/108688 * match.pd (bit_field_ref [bit_insert]): Simplify BIT_FIELD_REF of BIT_INSERT_EXPR extracting exactly all inserted bits even when without mode precision. Formatting fixes. * gcc.c-torture/compile/pr108688-1.c: Add PR number as comment. * gcc.dg/pr108688.c: New test.
