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
This commit is contained in:
Jim Grosbach 2009-08-20 01:03:48 +00:00
parent f636b9698c
commit 8fc3b6903a

View File

@ -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<InvokeInst*,16> &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<PHINode>(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<BasicBlock*,unsigned> PadSites;
unsigned NextCallSiteValue = 1;
for (SmallVector<InvokeInst*,16>::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)