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From: Michael Meissner <meissner@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc(refs/users/meissner/heads/work122)] Update ChangeLog.meissner Date: Fri, 9 Jun 2023 01:33:30 +0000 (GMT) [thread overview] Message-ID: <20230609013330.9EA133858438@sourceware.org> (raw) https://gcc.gnu.org/g:7dd6680a5397d2f23f4fba8bb91f7739bd244e23 commit 7dd6680a5397d2f23f4fba8bb91f7739bd244e23 Author: Michael Meissner <meissner@linux.ibm.com> Date: Thu Jun 8 21:33:22 2023 -0400 Update ChangeLog.meissner Diff: --- gcc/ChangeLog.meissner | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/gcc/ChangeLog.meissner b/gcc/ChangeLog.meissner index 63644d60a12..3bca12eb10e 100644 --- a/gcc/ChangeLog.meissner +++ b/gcc/ChangeLog.meissner @@ -10,28 +10,29 @@ There are several problems with the current GCC: 1) The prefixed attribute was not checking insns with the type fused_load_cmpi for being load insns. This meant if the load + compare - fusion was not split, it would not know that the load should be - prefixed. + fusion was not split, the insn size might be off, and the wrong + instruction might be generated. - 2) The recognition of LWA for being prefixed looks at the "sign_extend" - attribute and whether the register mode was different than the memory - load (i.e. does it have a sign_extend wrapper around the load). + 2) The code in prefixed_load_p looks at the "sign_extend" attribute and + whether the register mode was different than the memory for SImode loads + to detect LWA instructions. 3) The constraints in fusion.md (generated by genfusion.pl) use "m" for LWA and LD, when they should use "YZ". - 4) There is a lwa_operand predicate that should be used instead of - ds_form_mem_operand for the LWA instruction. + 4) The code to determine whether to split the insn if it has a prefixed + address was passing in SImode. For LWA, we need to pass in DImode and + not SImode to properly determine if the address is prefixed. -The main fix is to modify genfusion.pl that it sets the appropriate predicates -and constraints. +The fix is to modify genfusion.pl that it sets the "YZ" constraint instead of +"m" for the ld and lwa instructions. -I also added support in genfusion.md so that if we are doing a LWA operation and -just setting the CC bits (throwing away the result of the load after the -comparison), it generates a LWZ instruction and does a CMPWI instead of CMPDI. -This way those loads can use normal D-FORM restrictions instead of DS-form. +I also set the signed attribute on the HI/SImode loads that do sign extension. -I set the "sign_extend" attribute on the cases that generate LWA. +I modified the predicate for lwa to use lwa_operand instead of the predicate +ds_form_mem_operand. This predicate has direct checks to prevent a prefixed lwa +from being generated. I also modified the condition for the insn splitter so +that it passes DImode for the lwa instructions and not SImode. I modified the "prefixed" attribute so that it also checks fused_load_cmpi. @@ -39,11 +40,8 @@ I modified the "prefixed" attribute so that it also checks fused_load_cmpi. gcc/ - * config/rs6000/genfusion.pl (gen_ld_cmpi_p10_one): Fix constraints and - predicates for LD and LWA. Optimize LWA/CMPDI to generate LWZ/CMPWI if - we don't need the result of the load after the comparison. Set the - sign_extend attribute for LWA instruction. For LWA where we do not need - the result of the load after the comparison, use LWZ and CMPWI. + * config/rs6000/genfusion.pl (gen_ld_cmpi_p10_one): Fix problems that + allowed prefixed lwa to be generated. * config/rs6000/fusion.md: Regenerate. * config/rs6000/rs6000.md (prefixed attribute): Treat fused_load_cmpi insns as being load insns. @@ -51,8 +49,8 @@ gcc/ gcc/testsuite/ * g++.target/powerpc/pr105325.C: New test. - * gcc.target/powerpc/fusion-p10-ldcmpi.c: Adjust names and insn counts - for PR target/105325 fix. + +==================== Branch work122, patch #2 was reverted ==================== ==================== Branch work122, patch #1 was reverted ====================
next reply other threads:[~2023-06-09 1:33 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-06-09 1:33 Michael Meissner [this message] -- strict thread matches above, loose matches on Subject: below -- 2023-06-13 23:25 Michael Meissner 2023-06-13 17:23 Michael Meissner 2023-06-13 2:58 Michael Meissner 2023-06-09 21:06 Michael Meissner 2023-06-09 6:10 Michael Meissner 2023-06-09 4:18 Michael Meissner 2023-06-08 16:54 Michael Meissner 2023-06-07 20:58 Michael Meissner 2023-06-07 18:57 Michael Meissner
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