6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-14 14:24:05 +00:00
Code Issues Projects Releases Wiki Activity

Debug info for optimized code: Support variables that are on the stack and

Browse Source 
described by DBG_VALUEs during their lifetime.

Previously, when a variable was at a FrameIndex for any part of its
lifetime, this would shadow all other DBG_VALUEs and only a single
fbreg location would be emitted, which in fact is only valid for a small
range and not the entire lexical scope of the variable. The included
dbg-value-const-byref testcase demonstrates this.

This patch fixes this by
Local
- emitting dbg.value intrinsics for allocas that are passed by reference
- dropping all dbg.declares (they are now fully lowered to dbg.values)
SelectionDAG
- renamed constructors for SDDbgValue for better readability.
- fix UserValue::match() to handle indirect values correctly
- not inserting an MMI table entries for dbg.values that describe allocas.
- lowering dbg.values that describe allocas into *indirect* DBG_VALUEs.
CodeGenPrepare
- leaving dbg.values for an alloca were they are (see comment)
Other
- regenerated/updated instcombine-intrinsics testcase and included source


rdar://problem/16679879
http://reviews.llvm.org/D3374

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207130 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Adrian Prantl
2014-04-24 17:41:45 +00:00
parent 35f9e1aa49
commit f28f471f16
10 changed files with 146 additions and 132 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
lib/Transforms/Utils/Local.cpp
View File

@ -1051,20 +1051,26 @@ bool llvm::LowerDbgDeclare(Function &F) {
AllocaInst *AI = dyn_cast_or_null<AllocaInst>(DDI->getAddress());
// If this is an alloca for a scalar variable, insert a dbg.value
// at each load and store to the alloca and erase the dbg.declare.
// The dbg.values allow tracking a variable even if it is not
// stored on the stack, while the dbg.declare can only describe
// the stack slot (and at a lexical-scope granularity). Later
// passes will attempt to elide the stack slot.
if (AI && !AI->isArrayAllocation()) {
// We only remove the dbg.declare intrinsic if all uses are
// converted to dbg.value intrinsics.
bool RemoveDDI = true;
for (User *U : AI->users())
if (StoreInst *SI = dyn_cast<StoreInst>(U))
ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
else if (LoadInst *LI = dyn_cast<LoadInst>(U))
ConvertDebugDeclareToDebugValue(DDI, LI, DIB);
else
RemoveDDI = false;
if (RemoveDDI)
DDI->eraseFromParent();
else if (Instruction *I = dyn_cast<Instruction>(U)) {
// This is a call by-value or some other instruction that
// takes a pointer to the variable. Insert a *value*
// intrinsic that describes the alloca.
auto DbgVal =
DIB.insertDbgValueIntrinsic(AI, 0,
DIVariable(DDI->getVariable()), I);
DbgVal->setDebugLoc(I->getDebugLoc());
}
DDI->eraseFromParent();
}
}
return true;