Date: Thu, 24 Sep 2015 21:20:00 +0000 (UTC) From: Dimitry Andric <dim@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r288195 - projects/clang370-import/contrib/llvm/include/llvm/Analysis Message-ID: <201509242120.t8OLK0HF045769@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: dim Date: Thu Sep 24 21:20:00 2015 New Revision: 288195 URL: https://svnweb.freebsd.org/changeset/base/288195 Log: Pull in r248439 from upstream llvm trunk (by Sanjay Patel): set div/rem default values to 'expensive' in TargetTransformInfo's cost model ...because that's what the cost model was intended to do. As discussed in D12882, this fix has a temporary unintended consequence for SimplifyCFG: it causes us to not speculate an fdiv. However, two wrongs make PR24818 right, and two wrongs make PR24343 act right even though it's really still wrong. I intend to correct SimplifyCFG and add to CodeGenPrepare to account for this cost model change and preserve the righteousness for the bug report cases. https://llvm.org/bugs/show_bug.cgi?id=24818 https://llvm.org/bugs/show_bug.cgi?id=24343 Differential Revision: http://reviews.llvm.org/D12882 This fixes the too-eager fdiv hoisting in pow(), which could lead to unexpected floating point exceptions. Modified: projects/clang370-import/contrib/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h Modified: projects/clang370-import/contrib/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h ============================================================================== --- projects/clang370-import/contrib/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h Thu Sep 24 21:04:48 2015 (r288194) +++ projects/clang370-import/contrib/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h Thu Sep 24 21:20:00 2015 (r288195) @@ -60,6 +60,14 @@ public: // Otherwise, the default basic cost is used. return TTI::TCC_Basic; + case Instruction::FDiv: + case Instruction::FRem: + case Instruction::SDiv: + case Instruction::SRem: + case Instruction::UDiv: + case Instruction::URem: + return TTI::TCC_Expensive; + case Instruction::IntToPtr: { // An inttoptr cast is free so long as the input is a legal integer type // which doesn't contain values outside the range of a pointer.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201509242120.t8OLK0HF045769>