replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fix fast-isel to avoid selecting the return instruction if a 

tail call has been encountered.

llvm-svn: 89444
This commit is contained in:
Dan Gohman 2009-11-20 02:51:26 +00:00
parent fc81352e3f
commit 20c8ab655e
3 changed files with 30 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
llvm/include/llvm/CodeGen/SelectionDAGISel.h
View File

@ -127,7 +127,8 @@ private:
void SelectBasicBlock(BasicBlock *LLVMBB,
BasicBlock::iterator Begin,
BasicBlock::iterator End);
BasicBlock::iterator End,
bool &HadTailCall);
void CodeGenAndEmitDAG();
void LowerArguments(BasicBlock *BB);

18
llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
View File

@ -376,7 +376,8 @@ static void copyCatchInfo(BasicBlock *SrcBB, BasicBlock *DestBB,
void SelectionDAGISel::SelectBasicBlock(BasicBlock *LLVMBB,
BasicBlock::iterator Begin,
BasicBlock::iterator End) {
BasicBlock::iterator End,
bool &HadTailCall) {
SDL->setCurrentBasicBlock(BB);
MetadataContext &TheMetadata = LLVMBB->getParent()->getContext().getMetadata();
unsigned MDDbgKind = TheMetadata.getMDKind("dbg");
@ -421,6 +422,7 @@ void SelectionDAGISel::SelectBasicBlock(BasicBlock *LLVMBB,
// Final step, emit the lowered DAG as machine code.
CodeGenAndEmitDAG();
HadTailCall = SDL->HasTailCall;
SDL->clear();
}
@ -797,7 +799,16 @@ void SelectionDAGISel::SelectAllBasicBlocks(Function &Fn,
}
SDL->setCurDebugLoc(FastIS->getCurDebugLoc());
SelectBasicBlock(LLVMBB, BI, next(BI));
bool HadTailCall = false;
SelectBasicBlock(LLVMBB, BI, next(BI), HadTailCall);
// If the call was emitted as a tail call, we're done with the block.
if (HadTailCall) {
BI = End;
break;
}
// If the instruction was codegen'd with multiple blocks,
// inform the FastISel object where to resume inserting.
FastIS->setCurrentBlock(BB);
@ -827,7 +838,8 @@ void SelectionDAGISel::SelectAllBasicBlocks(Function &Fn,
// If FastISel is run and it has known DebugLoc then use it.
if (FastIS && !FastIS->getCurDebugLoc().isUnknown())
SDL->setCurDebugLoc(FastIS->getCurDebugLoc());
SelectBasicBlock(LLVMBB, BI, End);
bool HadTailCall;
SelectBasicBlock(LLVMBB, BI, End, HadTailCall);
}
FinishBasicBlock();

13
llvm/test/CodeGen/X86/tailcall-fastisel.ll Normal file
View File

@ -0,0 +1,13 @@
; RUN: llc < %s -march=x86-64 -tailcallopt -fast-isel | grep TAILCALL
; Fast-isel shouldn't attempt to handle this tail call, and it should
; cleanly terminate instruction selection in the block after it's
; done to avoid emitting invalid MachineInstrs.
%0 = type { i64, i32, i8* }
define fastcc i8* @"visit_array_aux<`Reference>"(%0 %arg, i32 %arg1) nounwind {
fail: ; preds = %entry
%tmp20 = tail call fastcc i8* @"visit_array_aux<`Reference>"(%0 %arg, i32 undef) ; <i8*> [#uses=1]
ret i8* %tmp20
}