6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-23 17:24:48 +00:00
Code Issues Projects Releases Wiki Activity

Revert r176154 in favor of a better approach.

Browse Source 
Code generation makes some basic assumptions about the IR it's been given. In
particular, if there is only one 'invoke' in the function, then that invoke
won't be going away. However, with the advent of the `llvm.donothing' intrinsic,
those invokes may go away. If all of them go away, the landing pad no longer has
any users. This confuses the back-end, which asserts.

This happens with SjLj exceptions, because that's the model that modifies the IR
based on there being invokes, etc. in the function.

Remove any invokes of `llvm.donothing' during SjLj EH preparation. This will
give us a CFG that the back-end won't be confused about. If all of the invokes
in a function are removed, then the SjLj EH prepare pass won't insert the bogus
code the relies upon the invokes being there.
<rdar://problem/13228754&13316637>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176677 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling
2013-03-08 02:21:08 +00:00
parent 4434a4f8bd
commit e36b47e17b
3 changed files with 50 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
lib/CodeGen/SjLjEHPrepare.cpp
View File

@ -379,13 +379,22 @@ void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F,
/// the function context and marking the call sites with the appropriate
/// values. These values are used by the DWARF EH emitter.
bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) {
SmallVector<ReturnInst*, 16> Returns;
SmallVector<InvokeInst*, 16> Invokes;
SmallVector<ReturnInst*, 16> Returns;
SmallVector<InvokeInst*, 16> Invokes;
SmallSetVector<LandingPadInst*, 16> LPads;
// Look through the terminators of the basic blocks to find invokes.
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
if (Function *Callee = II->getCalledFunction())
if (Callee->isIntrinsic() &&
Callee->getIntrinsicID() == Intrinsic::donothing) {
// Remove the NOP invoke.
BranchInst::Create(II->getNormalDest(), II);
II->eraseFromParent();
continue;
}
Invokes.push_back(II);
LPads.insert(II->getUnwindDest()->getLandingPadInst());
} else if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {