From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw1-x1132.google.com (mail-yw1-x1132.google.com [IPv6:2607:f8b0:4864:20::1132]) by sourceware.org (Postfix) with ESMTPS id 57BB93858C2B for ; Tue, 31 Jan 2023 09:05:51 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 57BB93858C2B Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-yw1-x1132.google.com with SMTP id 00721157ae682-510476ee20aso87404627b3.3 for ; Tue, 31 Jan 2023 01:05:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=ArmI2Mpj5zj2I2/3Ss0AqNIo5Ec6rbLRiLYVN36m8U0=; b=fIhbfAEcmvA16MW10PWP+kWGcX21AXovGNr0+wDM8V+9IKQvoTJf+MQ+Y2vWnTuKze ywOnhX9GJzkyC+qk0Nzf0mZTvIbvJuXKBXsSePJLAp4TYiGP0LcxbglWiRlnyoAgx/Fy HmIRMyY0r8C+TNMm0oFILCUWtuEAiusaANP4ej5mrLuU/EH2MsD+VPohyKUHhlrjM2VD JwT0rJgcIRWrBBODJDmaeTC+NcMEUzHVue1PpeZnFG0ETVnlanmTVbxgwYGcVcZkbADN 7j2gVr7eVnBRJwG0+RZXa78+/ZsQ8y9RgluLc+6Yoy/hqOMb2ST/sNfbbOfMVgxuLJ/h J3uw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=ArmI2Mpj5zj2I2/3Ss0AqNIo5Ec6rbLRiLYVN36m8U0=; b=nA6Pzv7gv7QNSxPBiFsaJ6voGgsyOj09Lm5uBfSF4lbzZz5DM/QmrhRfSYuK4sBF5h MFdK7fc+5ZUI7apNqBwFqs+airX6omNVwJKguHLCaXzThYMfWqudemDbu7SqrwzDrI8V Z1OXBhL4T7b4bdXjcgR/0HTYzwld2Lt69R1v0fY5Fg3RVBKm9Q2kWFu+a3VNyZVdgmXL tNnvMMTyXacu7mAS2naxaDneFlhzZ4CyLOjXNBiAbc/1tqkZpiLQByzUgMO24Trc5VP2 dfBLrjgpVPMA4W3NTp02c85MiI+hzpwzLZrrs0TeENmxefuUBjKUSPDAwi3VbiUB9LUx uTyg== X-Gm-Message-State: AO0yUKXDQzvp9DpnUAFPb67uRXQKi0IFayVegWe2+5dcOcsng+AqY6ch 6o8PR2o+vXEBn5XbrjW6ufQ00bM8ebqpvmrAurc= X-Google-Smtp-Source: AK7set+/imXjHKIiC3+rodMcZ160GwbbxAotQNAZhSrGLDjASXvbyHF4e13xt/Nk9WiW/91xOmkICqmN6r/yVaxNeaQ= X-Received: by 2002:a81:6c87:0:b0:506:c617:9e38 with SMTP id h129-20020a816c87000000b00506c6179e38mr2649275ywc.54.1675155950721; Tue, 31 Jan 2023 01:05:50 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Uros Bizjak Date: Tue, 31 Jan 2023 10:05:39 +0100 Message-ID: Subject: Re: [PATCH] i386: Fix up ix86_convert_const_wide_int_to_broadcast [PR108599] To: Jakub Jelinek Cc: Hongtao Liu , gcc-patches@gcc.gnu.org Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.6 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,KAM_SHORT,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Tue, Jan 31, 2023 at 9:02 AM Jakub Jelinek wrote: > > Hi! > > The following testcase is miscompiled. The problem is that during > RTL DSE we see a V4DI register is being loaded { 16, 16, 0, 0 } > value and DSE mostly works in terms of scalar modes, so it calls > movoi to set an OImode REG to (const_wide_int 0x100000000000000010) > and ix86_convert_const_wide_int_to_broadcast thinks it can compute > that value by broadcasting DImode 0x10. While it is true that > for TImode result the broadcast could be used, for OImode/XImode > it can't be, because all but the lowest 2 HOST_WIDE_INTs aren't > present (so are 0 or -1 depending on sign), not 0x10 in this case. > The function checks if the least significant HOST_WIDE_INT elt > of the CONST_WIDE_INT is broadcastable from QI/HI/SI/DImode and then > /* Check if OP can be broadcasted from VAL. */ > for (int i = 1; i < CONST_WIDE_INT_NUNITS (op); i++) > if (val != CONST_WIDE_INT_ELT (op, i)) > return nullptr; > That is needed of course, but nothing checks that > CONST_WIDE_INT_NUNITS (op) isn't too small for the mode in question. > I think if op would be 0 or -1, it ought to be never CONST_WIDE_INT, > but CONST_INT and so we can just punt whenever the number of > CONST_WIDE_INT elts is not the expected one. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? > > 2023-01-31 Jakub Jelinek > > PR target/108599 > * config/i386/i386-expand.cc > (ix86_convert_const_wide_int_to_broadcast): Return nullptr if > CONST_WIDE_INT_NUNITS (op) times HOST_BITS_PER_WIDE_INT isn't > equal to bitsize of mode. > > * gcc.target/i386/avx2-pr108599.c: New test. OK. Thanks, Uros. > > --- gcc/config/i386/i386-expand.cc.jj 2023-01-19 23:22:05.306066616 +0100 > +++ gcc/config/i386/i386-expand.cc 2023-01-30 15:33:43.418598714 +0100 > @@ -291,7 +291,9 @@ ix86_convert_const_wide_int_to_broadcast > broadcast only if vector broadcast is available. */ > if (!TARGET_AVX > || !CONST_WIDE_INT_P (op) > - || standard_sse_constant_p (op, mode)) > + || standard_sse_constant_p (op, mode) > + || (CONST_WIDE_INT_NUNITS (op) * HOST_BITS_PER_WIDE_INT > + != GET_MODE_BITSIZE (mode))) > return nullptr; > > HOST_WIDE_INT val = CONST_WIDE_INT_ELT (op, 0); > --- gcc/testsuite/gcc.target/i386/avx2-pr108599.c.jj 2023-01-30 16:04:31.984429702 +0100 > +++ gcc/testsuite/gcc.target/i386/avx2-pr108599.c 2023-01-30 16:04:24.459540223 +0100 > @@ -0,0 +1,32 @@ > +/* PR target/108599 */ > +/* { dg-do run { target avx2 } } */ > +/* { dg-options "-O2 -mavx2 -mtune=skylake-avx512" } */ > + > +#include "avx2-check.h" > + > +struct S { unsigned long long a, b, c, d; }; > + > +__attribute__((noipa)) void > +foo (unsigned long long x, unsigned long long y, > + unsigned long long z, unsigned long long w, const struct S s) > +{ > + if (s.a != x || s.b != y || s.c != z || s.d != w) > + abort (); > +} > + > +typedef unsigned long long V __attribute__((may_alias, vector_size (4 * sizeof (unsigned long long)))); > + > +static void > +avx2_test (void) > +{ > + { > + struct S s; > + *(V *)&s = (V) { 16, 0, 0, 0 }; > + foo (16, 0, 0, 0, s); > + } > + { > + struct S s; > + *(V *)&s = (V) { 16, 16, 0, 0 }; > + foo (16, 16, 0, 0, s); > + } > +} > > Jakub >