[{"id":3685539,"web_url":"http://patchwork.ozlabs.org/comment/3685539/","msgid":"","list_archive_url":null,"date":"2026-05-04T07:42:18","subject":"Re: [PATCH v3] RISC-V: Apply LMUL cost scaling to vector operations","submitter":{"id":86205,"url":"http://patchwork.ozlabs.org/api/people/86205/","name":"Robin Dapp","email":"rdapp.gcc@gmail.com"},"content":"> This patch introduces multiplicative cost scaling (x2/x4/x8) to model\n> the higher latency and register pressure of larger LMULs. The scaling\n> is applied uniformly in adjust_stmt_cost for all vector operations.\n>\n> In addition to VLA, VLS should also get the same LMUL cost scaling,\n> but doing so causes too many testsuite regressions currently,\n> mostly because these tests also need expectation updates.\n> This is left for future work.\n\nLGTM but the CI (via https://patchwork.sourceware.org/project/gcc/list/?q=risc-v)\nstill flags two failures:\n\nhttps://github.com/ewlu/gcc-precommit-ci/issues/4509#issuecomment-4368190788\n\nXPASS: gcc.dg/vect/costmodel/riscv/rvv/pr113112-4.c scan-assembler-not e64,m2\n\nand\n\nFAIL: gcc.target/riscv/rvv/autovec/partial/slp_run-17.c -ftree-vectorize -O3 \n-mrvv-max-lmul=m4 execution test\n\nThe latter is surely pre existing and not caused by your patch. It would be \ngood to have a short look what's going wrong there and perhaps open a PR once \nyou commit this (with the XPASS fixed).","headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256\n header.s=20251104 header.b=Ul0a60zl;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; helo=vm01.sourceware.org;\n envelope-from=gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org;\n receiver=patchwork.ozlabs.org)","sourceware.org;\n\tdkim=pass (2048-bit key,\n unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256\n header.s=20251104 header.b=Ul0a60zl","sourceware.org;\n dmarc=pass (p=none dis=none) header.from=gmail.com","sourceware.org; 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charset=UTF-8","Date":"Mon, 04 May 2026 09:42:18 +0200","Message-Id":"","To":"\"Zhongyao Chen\" , ","From":"\"Robin Dapp\" ","Subject":"Re: [PATCH v3] RISC-V: Apply LMUL cost scaling to vector operations","Cc":", , ","References":"<20260504034510.3574-1-chen.zhongyao@zte.com.cn>","In-Reply-To":"<20260504034510.3574-1-chen.zhongyao@zte.com.cn>","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"}}]