GlobalISel: put debug info for static allocas in the MachineFunction.
The good reason to do this is that static allocas are pretty simple to handle
(especially at -O0) and avoiding tracking DBG_VALUEs throughout the pipeline
should give some kind of performance benefit.
The bad reason is that the debug pipeline is an unholy mess of implicit
contracts, where determining whether "DBG_VALUE %reg, imm" actually implies a
load or not involves the services of at least 3 soothsayers and the sacrifice
of at least one chicken. And it still gets it wrong if the variable is at SP
directly.
llvm-svn: 297410
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 4d1ac68..b6ce59d 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -598,18 +598,18 @@
return true;
}
- unsigned Reg = getOrCreateVReg(*Address);
- auto RegDef = MRI->def_instr_begin(Reg);
assert(DI.getVariable()->isValidLocationForIntrinsic(
MIRBuilder.getDebugLoc()) &&
"Expected inlined-at fields to agree");
-
- if (RegDef != MRI->def_instr_end() &&
- RegDef->getOpcode() == TargetOpcode::G_FRAME_INDEX) {
- MIRBuilder.buildFIDbgValue(RegDef->getOperand(1).getIndex(),
- DI.getVariable(), DI.getExpression());
+ auto AI = dyn_cast<AllocaInst>(Address);
+ if (AI && AI->isStaticAlloca()) {
+ // Static allocas are tracked at the MF level, no need for DBG_VALUE
+ // instructions (in fact, they get ignored if they *do* exist).
+ MF->setVariableDbgInfo(DI.getVariable(), DI.getExpression(),
+ getOrCreateFrameIndex(*AI), DI.getDebugLoc());
} else
- MIRBuilder.buildDirectDbgValue(Reg, DI.getVariable(), DI.getExpression());
+ MIRBuilder.buildDirectDbgValue(getOrCreateVReg(*Address),
+ DI.getVariable(), DI.getExpression());
return true;
}
case Intrinsic::vaend: