From 8fc3b6903ac555e21d6c64c34f9815781e68c88b Mon Sep 17 00:00:00 2001 From: Jim Grosbach Date: Thu, 20 Aug 2009 01:03:48 +0000 Subject: [PATCH] Check for shared landing pads when assigning call site values. Invokes which share a landing pad should also use the same call site value. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79501 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SjLjEHPrepare.cpp | 54 ++++++++++++++++++++++------------- 1 file changed, 34 insertions(+), 20 deletions(-) diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp index 58b5213a0ea..91a85c07196 100644 --- a/lib/CodeGen/SjLjEHPrepare.cpp +++ b/lib/CodeGen/SjLjEHPrepare.cpp @@ -24,6 +24,7 @@ #include "llvm/CodeGen/Passes.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include "llvm/Transforms/Utils/Local.h" +#include "llvm/ADT/DenseMap.h" #include "llvm/ADT/Statistic.h" #include "llvm/ADT/SmallVector.h" #include "llvm/Support/CommandLine.h" @@ -69,8 +70,7 @@ namespace { private: void markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, - Value *CallSite, - SwitchInst *CatchSwitch); + Value *CallSite); void splitLiveRangesLiveAcrossInvokes(SmallVector &Invokes); bool insertSjLjEHSupport(Function &F); }; @@ -125,14 +125,9 @@ bool SjLjEHPass::doInitialization(Module &M) { /// markInvokeCallSite - Insert code to mark the call_site for this invoke void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, - Value *CallSite, - SwitchInst *CatchSwitch) { + Value *CallSite) { ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()), InvokeNo); - // The runtime comes back to the dispatcher with the call_site - 1 in - // the context. Odd, but there it is. - ConstantInt *SwitchValC = ConstantInt::get(Type::getInt32Ty(II->getContext()), - InvokeNo - 1); // If the unwind edge has phi nodes, split the edge. if (isa(II->getUnwindDest()->begin())) { @@ -149,8 +144,6 @@ void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, // location afterward. new StoreInst(CallSiteNoC, CallSite, true, II); // volatile - // Add a switch case to our unwind block. - CatchSwitch->addCase(SwitchValC, II->getUnwindDest()); // We still want this to look like an invoke so we emit the LSDA properly // FIXME: ??? Or will this cause strangeness with mis-matched IDs like // when it was in the front end? @@ -294,13 +287,6 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { if (!Invokes.empty()) { // We have invokes, so we need to add register/unregister calls to get // this function onto the global unwind stack. - // - // First thing we need to do is scan the whole function for values that are - // live across unwind edges. Each value that is live across an unwind edge - // we spill into a stack location, guaranteeing that there is nothing live - // across the unwind edge. This process also splits all critical edges - // coming out of invoke's. - splitLiveRangesLiveAcrossInvokes(Invokes); BasicBlock *EntryBB = F.begin(); // Create an alloca for the incoming jump buffer ptr and the new jump buffer @@ -472,11 +458,32 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { ContBlock->getTerminator()); Register->setDoesNotThrow(); - // At this point, we are all set up, update the invoke instructions + // At this point, we are all set up. Update the invoke instructions // to mark their call_site values, and fill in the dispatch switch // accordingly. - for (unsigned i = 0, e = Invokes.size(); i != e; ++i) - markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch); + DenseMap PadSites; + unsigned NextCallSiteValue = 1; + for (SmallVector::iterator I = Invokes.begin(), + E = Invokes.end(); I < E; ++I) { + unsigned CallSiteValue; + BasicBlock *LandingPad = (*I)->getSuccessor(1); + // landing pads can be shared. If we see a landing pad again, we + // want to make sure to use the same call site index so the dispatch + // will go to the right place. + CallSiteValue = PadSites[LandingPad]; + if (!CallSiteValue) { + CallSiteValue = NextCallSiteValue++; + PadSites[LandingPad] = CallSiteValue; + // Add a switch case to our unwind block. The runtime comes back + // to the dispatcher with the call_site - 1 in the context. Odd, + // but there it is. + ConstantInt *SwitchValC = + ConstantInt::get(Type::getInt32Ty((*I)->getContext()), + CallSiteValue - 1); + DispatchSwitch->addCase(SwitchValC, (*I)->getUnwindDest()); + } + markInvokeCallSite(*I, CallSiteValue, CallSite); + } // The front end has likely added calls to _Unwind_Resume. We need // to find those calls and mark the call_site as -1 immediately prior. @@ -504,6 +511,13 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { Unwinds[i]->eraseFromParent(); } + // Scan the whole function for values that are live across unwind edges. + // Each value that is live across an unwind edge we spill into a stack + // location, guaranteeing that there is nothing live across the unwind + // edge. This process also splits all critical edges coming out of + // invoke's. + splitLiveRangesLiveAcrossInvokes(Invokes); + // Finally, for any returns from this function, if this function contains an // invoke, add a call to unregister the function context. for (unsigned i = 0, e = Returns.size(); i != e; ++i) -- 2.34.1