From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by sourceware.org (Postfix) with ESMTP id 9440F3858D33 for ; Tue, 6 Jun 2023 16:45:02 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 9440F3858D33 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=kernel.crashing.org Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 356GgvdA031913; Tue, 6 Jun 2023 11:42:57 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 356GguQ2031912; Tue, 6 Jun 2023 11:42:56 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Tue, 6 Jun 2023 11:42:56 -0500 From: Segher Boessenkool To: Umesh Kalappa Cc: Andrew Pinski , Nicholas Piggin , linuxppc-dev@lists.ozlabs.org, gcc@gcc.gnu.org, libc-alpha@sourceware.org, Michael Ellerman , Paul E Murphy Subject: Re: Passing the complex args in the GPR's Message-ID: <20230606164256.GQ19790@gate.crashing.org> References: <20220524093828.505575-1-npiggin@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,JMQ_SPF_NEUTRAL,KAM_DMARC_STATUS,SPF_HELO_PASS,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi! On Tue, Jun 06, 2023 at 08:35:22PM +0530, Umesh Kalappa wrote: > Hi Adnrew, > Thank you for the quick response and for PPC64 too ,we do have > mismatches in ABI b/w complex operations like > https://godbolt.org/z/bjsYovx4c . > > Any reason why GCC chose to use GPR 's here ? What did you expect, what happened instead? Why did you expect that, and why then is it an error what did happen? You used -O0. As long as the code works, all is fine. But unoptimised code frequently is hard to read, please use -O2 instead? As Andrew says, why did you use -m32 for GCC but -m64 for LLVM? It is hard to compare those at all! 32-bit PowerPC Linux ABI (based on 32-bit PowerPC ELF ABI from 1995, BE version) vs. 64-bit ELFv2 ABI from 2015 (LE version). Segher