From patchwork Thu Dec 1 07:56:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 13061032 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CE5BC43217 for ; Thu, 1 Dec 2022 07:58:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229870AbiLAH6M (ORCPT ); Thu, 1 Dec 2022 02:58:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229925AbiLAH5t (ORCPT ); Thu, 1 Dec 2022 02:57:49 -0500 Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0C8F83259; Wed, 30 Nov 2022 23:57:20 -0800 (PST) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4NN7hK2X0Xz9sZs; Thu, 1 Dec 2022 08:57:05 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id iG_uvUsi9AHU; Thu, 1 Dec 2022 08:57:05 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4NN7hD3nz5z9sZv; Thu, 1 Dec 2022 08:57:00 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 6AFC58B790; Thu, 1 Dec 2022 08:57:00 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id s9cs-cE-xsxk; Thu, 1 Dec 2022 08:57:00 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (unknown [172.25.230.108]) by messagerie.si.c-s.fr (Postfix) with ESMTP id DBA528B78C; Thu, 1 Dec 2022 08:56:59 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.16.1) with ESMTPS id 2B17uvd3130837 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 1 Dec 2022 08:56:57 +0100 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 2B17uvEt130835; Thu, 1 Dec 2022 08:56:57 +0100 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Michael Ellerman , Nicholas Piggin , "Naveen N. Rao" Cc: Christophe Leroy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa Subject: [PATCH v1 08/10] powerpc/bpf/32: Optimise some particular const operations Date: Thu, 1 Dec 2022 08:56:33 +0100 Message-Id: <3dce3db8a490a053b5e0bf11ddaa6665f95422c1.1669881248.git.christophe.leroy@csgroup.eu> X-Mailer: git-send-email 2.38.1 In-Reply-To: References: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1669881391; l=2234; s=20211009; h=from:subject:message-id; bh=VwMKF2Awkd37GsVn0u5EZiXK9a3k4RENHDOgOO9LVEY=; b=5t5D82yM8v/1TM6KY7mduXB3rodDFp5mXkqWfbNzo8deF0CjLCkBzEhDK3HZOFaRc/jxw5TuhJ/n q43XJmuYDUAy9x2yflHjm/QoPCP4EdowwDyhhHGIXpleulXB/Wz4 X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Simplify multiplications and divisions with constants when the constant is 1 or -1. When the constant is a power of 2, replace them by bit shits. Signed-off-by: Christophe Leroy --- arch/powerpc/net/bpf_jit_comp32.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index 6c45d953d4e8..e6e156c0c5d6 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -391,7 +391,13 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg)); break; case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */ - if (imm >= -32768 && imm < 32768) { + if (imm == 1) + break; + if (imm == -1) { + EMIT(PPC_RAW_SUBFIC(dst_reg, dst_reg, 0)); + } else if (is_power_of_2((u32)imm)) { + EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, ilog2(imm))); + } else if (imm >= -32768 && imm < 32768) { EMIT(PPC_RAW_MULI(dst_reg, dst_reg, imm)); } else { PPC_LI32(_R0, imm); @@ -411,6 +417,13 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * EMIT(PPC_RAW_SUBFZE(dst_reg_h, dst_reg_h)); break; } + if (imm > 0 && is_power_of_2(imm)) { + imm = ilog2(imm); + EMIT(PPC_RAW_RLWINM(dst_reg_h, dst_reg_h, imm, 0, 31 - imm)); + EMIT(PPC_RAW_RLWIMI(dst_reg_h, dst_reg, imm, 32 - imm, 31)); + EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, imm)); + break; + } bpf_set_seen_register(ctx, tmp_reg); PPC_LI32(tmp_reg, imm); EMIT(PPC_RAW_MULW(dst_reg_h, dst_reg_h, tmp_reg)); @@ -438,8 +451,12 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * if (imm == 1) break; - PPC_LI32(_R0, imm); - EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, _R0)); + if (is_power_of_2((u32)imm)) { + EMIT(PPC_RAW_SRWI(dst_reg, dst_reg, ilog2(imm))); + } else { + PPC_LI32(_R0, imm); + EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, _R0)); + } break; case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */ if (!imm)