Date: Tue, 19 Nov 2013 17:53:19 +0000 (UTC) From: Dimitry Andric <dim@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r258350 - head/contrib/llvm/lib/Analysis Message-ID: <201311191753.rAJHrJB6009585@svn.freebsd.org>
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Author: dim Date: Tue Nov 19 17:53:19 2013 New Revision: 258350 URL: http://svnweb.freebsd.org/changeset/base/258350 Log: Pull in r191896 from upstream llvm trunk: CaptureTracking: Plug a loophole in the "too many uses" heuristic. The heuristic was added to avoid spending too much compile time in a specially crafted test case (PR17461, PR16474) with many uses on a select or bitcast instruction can still trigger the slow case. Add a check for that case. This only affects compile time, don't have a good way to test it. This fixes the excessive compile time spent on a specific file of the graphics/rawtherapee port. Reported by: mandree MFC after: 3 days Modified: head/contrib/llvm/lib/Analysis/CaptureTracking.cpp Modified: head/contrib/llvm/lib/Analysis/CaptureTracking.cpp ============================================================================== --- head/contrib/llvm/lib/Analysis/CaptureTracking.cpp Tue Nov 19 16:11:03 2013 (r258349) +++ head/contrib/llvm/lib/Analysis/CaptureTracking.cpp Tue Nov 19 17:53:19 2013 (r258350) @@ -146,8 +146,14 @@ void llvm::PointerMayBeCaptured(const Va case Instruction::PHI: case Instruction::Select: // The original value is not captured via this if the new value isn't. + Count = 0; for (Instruction::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE; ++UI) { + // If there are lots of uses, conservatively say that the value + // is captured to avoid taking too much compile time. + if (Count++ >= Threshold) + return Tracker->tooManyUses(); + Use *U = &UI.getUse(); if (Visited.insert(U)) if (Tracker->shouldExplore(U))
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