From nobody Wed Jul 31 07:37:00 2024 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4WYkSX6z18z5RP2w; Wed, 31 Jul 2024 07:37:00 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R11" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4WYkSX5K30z4pL5; Wed, 31 Jul 2024 07:37:00 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1722411420; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Q3iv6M7PbSPY98s4/JIuw7wMtI2nGJf8h5zJB/CbmKw=; b=S8FjzOFTreGRUsZE5JSgs43pPD3Ubv9VVdV8BeZrMtoJyFf2Uf5Ky//3rY9jXoYkeStwHk UtwhxOeBIfTJAUc1mpFTk6+LM6F9GUYaMKFm84XBqGLvDuL5bj2P4tV1XbsSoW7ZvEsLUW OpRgm6LcysYqBBcX0XVB0wzHpKWRQpVcsNzsMD/nQzEMwpsWKMDvVrk9zxQcMok/d0naWD RKDEIeWnvYiZIY9kFyK9ChZCwu0klJ4wzWEbqVUZuG0DeMCn16rHEBW4+8PdEQnTx7JxDj g8sk2Dz9ynrAa45YR9cOh/zMyTl8ckyT5jwiJIKaMGPLYOzwf8UMMJgLuJJ7Eg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1722411420; a=rsa-sha256; cv=none; b=XbtM0FdWYS9g/OTa6iIjG6+07VSr+AK1HdT9P8ahl9+sHfpYu1yDRRnAdwUHi969XsM4f1 Cou5quVYPmZC/4fD3rHO2UhGvVd/MDuFobp7qvfBSufXjA+2PfZxjusbBWyRXvxF4ASexx GNk0Q7Z10Y60w1qCSgebZKOVdbMWBpXBZkG43ZYEXl/GlCJ9x1mLdZ2W4wo9+sqdz1dDvY F/gy5pDucITI6CXPQBagq2Xyf+2UJA6SuP+PbAFfBoVwonBTGJY5vmEbTpg0VcwhFWRok8 etuhQBGQ38YyTUQOrReW+3zUQSprXTFbNXRog/9SnSx4wWfp74oylToO88nU7g== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1722411420; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Q3iv6M7PbSPY98s4/JIuw7wMtI2nGJf8h5zJB/CbmKw=; b=rtHQvS15Y3F3d+zhiH4GkgJui/1O+vMQIWbYEVgBDlzqdqvxuldBZTIxWHA48f4a5ny5yl xlL/3Egtg/g7Qz5yIgi4pE9wERnwxdK9jET8ct4iDflBMcf64al19gCMVsh7DnJlx8Ipx9 zQ0FO2hchOkId4Jk07yi5aKVNAgw8PBgOgbIFwHE9mEFkfdFXK/DNTcdYd8ujgb49KfmZc DwkUjn41d02Bv1v5bCxa5uQi1a0BZrJ6QYIlYAUrmvNNZPZl5i7M2ufy24ywg1YTdbtrGz SpcSZA8/Daia/rYeSTxEgk7mdyEW86fouv8YDQ1ZalZjRw1XMstvUv7fajhepA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4WYkSX4xLNzsVh; Wed, 31 Jul 2024 07:37:00 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 46V7b0ga073326; Wed, 31 Jul 2024 07:37:00 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 46V7b0lk073323; Wed, 31 Jul 2024 07:37:00 GMT (envelope-from git) Date: Wed, 31 Jul 2024 07:37:00 GMT Message-Id: <202407310737.46V7b0lk073323@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Dimitry Andric Subject: git: 814641415fbe - stable/13 - Merge commit c80c09f3e380 from llvm-project (by Dimitry Andric): List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: dim X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: 814641415fbee707b312c334e00a1ebb5157e37b Auto-Submitted: auto-generated The branch stable/13 has been updated by dim: URL: https://cgit.FreeBSD.org/src/commit/?id=814641415fbee707b312c334e00a1ebb5157e37b commit 814641415fbee707b312c334e00a1ebb5157e37b Author: Dimitry Andric AuthorDate: 2024-07-28 11:13:37 +0000 Commit: Dimitry Andric CommitDate: 2024-07-31 07:29:59 +0000 Merge commit c80c09f3e380 from llvm-project (by Dimitry Andric): [CalcSpillWeights] Avoid x87 excess precision influencing weight result Fixes #99396 The result of `VirtRegAuxInfo::weightCalcHelper` can be influenced by x87 excess precision, which can result in slightly different register choices when the compiler is hosted on x86_64 or i386. This leads to different object file output when cross-compiling to i386, or native. Similar to 7af3432e22b0, we need to add a `volatile` qualifier to the local `Weight` variable to force it onto the stack, and avoid the excess precision. Define `stack_float_t` in `MathExtras.h` for this purpose, and use it. This is the version of the fix for PR276961 that landed upstream. PR: 276961 Reported by: cperciva MFC after: 3 days (cherry picked from commit 1a4b8325f6e3a45c77188343da504fe04495cc46) --- contrib/llvm-project/llvm/include/llvm/Support/MathExtras.h | 8 ++++++++ contrib/llvm-project/llvm/lib/CodeGen/CalcSpillWeights.cpp | 11 ++++++----- 2 files changed, 14 insertions(+), 5 deletions(-) diff --git a/contrib/llvm-project/llvm/include/llvm/Support/MathExtras.h b/contrib/llvm-project/llvm/include/llvm/Support/MathExtras.h index aa4f4d2ed42e..afb4fa262152 100644 --- a/contrib/llvm-project/llvm/include/llvm/Support/MathExtras.h +++ b/contrib/llvm-project/llvm/include/llvm/Support/MathExtras.h @@ -644,6 +644,14 @@ std::enable_if_t, T> MulOverflow(T X, T Y, T &Result) { return UX > (static_cast(std::numeric_limits::max())) / UY; } +/// Type to force float point values onto the stack, so that x86 doesn't add +/// hidden precision, avoiding rounding differences on various platforms. +#if defined(__i386__) || defined(_M_IX86) +using stack_float_t = volatile float; +#else +using stack_float_t = float; +#endif + } // End llvm namespace #endif diff --git a/contrib/llvm-project/llvm/lib/CodeGen/CalcSpillWeights.cpp b/contrib/llvm-project/llvm/lib/CodeGen/CalcSpillWeights.cpp index f3cb7fa5af61..fa7ef669ec11 100644 --- a/contrib/llvm-project/llvm/lib/CodeGen/CalcSpillWeights.cpp +++ b/contrib/llvm-project/llvm/lib/CodeGen/CalcSpillWeights.cpp @@ -22,6 +22,7 @@ #include "llvm/CodeGen/TargetSubtargetInfo.h" #include "llvm/CodeGen/VirtRegMap.h" #include "llvm/Support/Debug.h" +#include "llvm/Support/MathExtras.h" #include "llvm/Support/raw_ostream.h" #include #include @@ -256,7 +257,9 @@ float VirtRegAuxInfo::weightCalcHelper(LiveInterval &LI, SlotIndex *Start, return -1.0f; } - float Weight = 1.0f; + // Force Weight onto the stack so that x86 doesn't add hidden precision, + // similar to HWeight below. + stack_float_t Weight = 1.0f; if (IsSpillable) { // Get loop info for mi. if (MI->getParent() != MBB) { @@ -283,11 +286,9 @@ float VirtRegAuxInfo::weightCalcHelper(LiveInterval &LI, SlotIndex *Start, Register HintReg = copyHint(MI, LI.reg(), TRI, MRI); if (!HintReg) continue; - // Force hweight onto the stack so that x86 doesn't add hidden precision, + // Force HWeight onto the stack so that x86 doesn't add hidden precision, // making the comparison incorrectly pass (i.e., 1 > 1 == true??). - // - // FIXME: we probably shouldn't use floats at all. - volatile float HWeight = Hint[HintReg] += Weight; + stack_float_t HWeight = Hint[HintReg] += Weight; if (HintReg.isVirtual() || MRI.isAllocatable(HintReg)) CopyHints.insert(CopyHint(HintReg, HWeight)); }