From 812e1e45de5aac14029573e9fb81885922a2120b Mon Sep 17 00:00:00 2001 From: "Duncan P. N. Exon Smith" Date: Fri, 11 Sep 2015 01:34:59 +0000 Subject: [PATCH] AsmWriter: Avoid O(N^2) processing of metadata Fix embarrassing bugs I introduced to the `SlotTracker` in or around r235785. I had us iterating through every instruction in a function (and hitting a map in the LLVMContext) for every basic block in the function. While there, completely avoid the call to `SlotTracker::processFunctionMetadata()` from `SlotTracker::processFunction()` if we've speculatively done this already in `SlotTracker::processModule()` by checking `ShouldInitializeAllMetadata` (this wasn't an algorithmic problem, but it's touching the same line of code). Fixes PR24699. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247372 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/IR/AsmWriter.cpp | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/lib/IR/AsmWriter.cpp b/lib/IR/AsmWriter.cpp index db7fd7a2324..56a002c0382 100644 --- a/lib/IR/AsmWriter.cpp +++ b/lib/IR/AsmWriter.cpp @@ -807,6 +807,10 @@ void SlotTracker::processFunction() { ST_DEBUG("begin processFunction!\n"); fNext = 0; + // Process function metadata if it wasn't hit at the module-level. + if (!ShouldInitializeAllMetadata) + processFunctionMetadata(*TheFunction); + // Add all the function arguments with no names. for(Function::const_arg_iterator AI = TheFunction->arg_begin(), AE = TheFunction->arg_end(); AI != AE; ++AI) @@ -820,8 +824,6 @@ void SlotTracker::processFunction() { if (!BB.hasName()) CreateFunctionSlot(&BB); - processFunctionMetadata(*TheFunction); - for (auto &I : BB) { if (!I.getType()->isVoidTy() && !I.hasName()) CreateFunctionSlot(&I); @@ -849,11 +851,11 @@ void SlotTracker::processFunction() { void SlotTracker::processFunctionMetadata(const Function &F) { SmallVector, 4> MDs; - for (auto &BB : F) { - F.getAllMetadata(MDs); - for (auto &MD : MDs) - CreateMetadataSlot(MD.second); + F.getAllMetadata(MDs); + for (auto &MD : MDs) + CreateMetadataSlot(MD.second); + for (auto &BB : F) { for (auto &I : BB) processInstructionMetadata(I); } -- 2.34.1