From c4d69165081237eb951509d74b1816601834a3e7 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 9 Dec 2004 04:51:50 +0000 Subject: [PATCH] Eliminate this ugly hack. This was put back in when replaceAllUsesOf used a different algorithm that was extremely inefficient for instructions with many operands. This reduces the time of this code snippet from .23s for 176.gcc to 0.03s in a debug build, which speeds up total llvm-dis time just barely. It's more of a code cleanup than a speedup. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18685 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Bytecode/Reader/Reader.cpp | 36 ++++++---------------------------- 1 file changed, 6 insertions(+), 30 deletions(-) diff --git a/lib/Bytecode/Reader/Reader.cpp b/lib/Bytecode/Reader/Reader.cpp index 8f0a7f8a8dc..9880ac405ae 100644 --- a/lib/Bytecode/Reader/Reader.cpp +++ b/lib/Bytecode/Reader/Reader.cpp @@ -30,6 +30,8 @@ #include using namespace llvm; +#include "llvm/Support/Timer.h" + namespace { /// @brief A class for maintaining the slot number definition @@ -1690,39 +1692,13 @@ void BytecodeReader::ParseFunctionBody(Function* F) { // Resolve forward references. Replace any uses of a forward reference value // with the real value. - - // replaceAllUsesWith is very inefficient for instructions which have a LARGE - // number of operands. PHI nodes often have forward references, and can also - // often have a very large number of operands. - // - // FIXME: REEVALUATE. replaceAllUsesWith is _much_ faster now, and this code - // should be simplified back to using it! - // - std::map ForwardRefMapping; - for (std::map, Value*>::iterator - I = ForwardReferences.begin(), E = ForwardReferences.end(); - I != E; ++I) - ForwardRefMapping[I->second] = getValue(I->first.first, I->first.second, - false); - - for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) - for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) - for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) - if (Value* V = I->getOperand(i)) - if (Argument *A = dyn_cast(V)) { - std::map::iterator It = ForwardRefMapping.find(A); - if (It != ForwardRefMapping.end()) I->setOperand(i, It->second); - } - while (!ForwardReferences.empty()) { - std::map, Value*>::iterator I = - ForwardReferences.begin(); + std::map, Value*>::iterator + I = ForwardReferences.begin(); + Value *V = getValue(I->first.first, I->first.second, false); Value *PlaceHolder = I->second; + PlaceHolder->replaceAllUsesWith(V); ForwardReferences.erase(I); - - // Now that all the uses are gone, delete the placeholder... - // If we couldn't find a def (error case), then leak a little - // memory, because otherwise we can't remove all uses! delete PlaceHolder; } -- 2.34.1