[llvm] a524f84 - [SelectionDAG][NFCI] Use common logic for identifying MMI vars
Felipe de Azevedo Piovezan via llvm-commits
llvm-commits at lists.llvm.org
Wed May 3 07:58:58 PDT 2023
Author: Felipe de Azevedo Piovezan
Date: 2023-05-03T10:58:31-04:00
New Revision: a524f84780297f12d4aba18c002ce3e7b3675011
URL: https://github.com/llvm/llvm-project/commit/a524f84780297f12d4aba18c002ce3e7b3675011
DIFF: https://github.com/llvm/llvm-project/commit/a524f84780297f12d4aba18c002ce3e7b3675011.diff
LOG: [SelectionDAG][NFCI] Use common logic for identifying MMI vars
After function argument lowering, but prior to instruction selection,
dbg declares pointing to function arguments are lowered using special
logic.
Later, during instruction selection (both "fast" and regular ISel), this
logic is "repeated" in order to identify which intrinsics have already
been lowered. This is bad for two reasons:
1. The logic is not _really_ repeated, the code is different, which
could lead to duplicate lowering of the intrinsic.
2. Even if the logic were repeated properly, this is still code
duplication.
This patch addresses these issues by storing all preprocessed
dbg.declare intrinsics in a set inside FuncInfo; the set is queried upon
instruction selection.
Differential Revision: https://reviews.llvm.org/D149682
Added:
Modified:
llvm/include/llvm/CodeGen/FunctionLoweringInfo.h
llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/CodeGen/FunctionLoweringInfo.h b/llvm/include/llvm/CodeGen/FunctionLoweringInfo.h
index e880b6227ef0b..4c17e8dcc41a6 100644
--- a/llvm/include/llvm/CodeGen/FunctionLoweringInfo.h
+++ b/llvm/include/llvm/CodeGen/FunctionLoweringInfo.h
@@ -35,6 +35,7 @@ namespace llvm {
class Argument;
class BasicBlock;
class BranchProbabilityInfo;
+class DbgDeclareInst;
class Function;
class Instruction;
class MachineFunction;
@@ -187,6 +188,10 @@ class FunctionLoweringInfo {
/// SelectionDAGISel::PrepareEHLandingPad().
unsigned ExceptionPointerVirtReg, ExceptionSelectorVirtReg;
+ /// Collection of dbg.declare instructions handled after argument
+ /// lowering and before ISel proper.
+ SmallPtrSet<const DbgDeclareInst *, 8> PreprocessedDbgDeclares;
+
/// set - Initialize this FunctionLoweringInfo with the given Function
/// and its associated MachineFunction.
///
diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
index f8fde640a3f27..3e6b6798dd230 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -1208,6 +1208,9 @@ bool FastISel::selectIntrinsicCall(const IntrinsicInst *II) {
return true;
}
+ if (FuncInfo.PreprocessedDbgDeclares.contains(DI))
+ return true;
+
const Value *Address = DI->getAddress();
if (!Address || isa<UndefValue>(Address)) {
LLVM_DEBUG(dbgs() << "Dropping debug info for " << *DI
@@ -1215,13 +1218,6 @@ bool FastISel::selectIntrinsicCall(const IntrinsicInst *II) {
return true;
}
- // Byval arguments with frame indices were already handled after argument
- // lowering and before isel.
- const auto *Arg =
- dyn_cast<Argument>(Address->stripInBoundsConstantOffsets());
- if (Arg && FuncInfo.getArgumentFrameIndex(Arg) != INT_MAX)
- return true;
-
std::optional<MachineOperand> Op;
if (Register Reg = lookUpRegForValue(Address))
Op = MachineOperand::CreateReg(Reg, false);
diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index df236c503e4b1..f5569ffdac3a8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -348,6 +348,7 @@ void FunctionLoweringInfo::clear() {
StatepointStackSlots.clear();
StatepointRelocationMaps.clear();
PreferredExtendType.clear();
+ PreprocessedDbgDeclares.clear();
}
/// CreateReg - Allocate a single virtual register for the given type.
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index df6b24f86941b..f4ca34ebfd582 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6125,12 +6125,14 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
return;
}
case Intrinsic::dbg_declare: {
+ const auto &DI = cast<DbgDeclareInst>(I);
// Debug intrinsics are handled separately in assignment tracking mode.
- if (AssignmentTrackingEnabled)
+ // Some intrinsics are handled right after Argument lowering.
+ if (AssignmentTrackingEnabled ||
+ FuncInfo.PreprocessedDbgDeclares.count(&DI))
return;
// Assume dbg.declare can not currently use DIArgList, i.e.
// it is non-variadic.
- const auto &DI = cast<DbgVariableIntrinsic>(I);
assert(!DI.hasArgList() && "Only dbg.value should currently use DIArgList");
DILocalVariable *Variable = DI.getVariable();
DIExpression *Expression = DI.getExpression();
@@ -6149,29 +6151,6 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
bool isParameter = Variable->isParameter() || isa<Argument>(Address);
- // Check if this variable can be described by a frame index, typically
- // either as a static alloca or a byval parameter.
- int FI = std::numeric_limits<int>::max();
- if (const auto *AI =
- dyn_cast<AllocaInst>(Address->stripInBoundsConstantOffsets())) {
- if (AI->isStaticAlloca()) {
- auto I = FuncInfo.StaticAllocaMap.find(AI);
- if (I != FuncInfo.StaticAllocaMap.end())
- FI = I->second;
- }
- } else if (const auto *Arg = dyn_cast<Argument>(
- Address->stripInBoundsConstantOffsets())) {
- FI = FuncInfo.getArgumentFrameIndex(Arg);
- }
-
- // llvm.dbg.declare is handled as a frame index in the MachineFunction
- // variable table.
- if (FI != std::numeric_limits<int>::max()) {
- LLVM_DEBUG(dbgs() << "Skipping " << DI
- << " (variable info stashed in MF side table)\n");
- return;
- }
-
SDValue &N = NodeMap[Address];
if (!N.getNode() && isa<Argument>(Address))
// Check unused arguments map.
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index d4e3f120107ad..36611b117296a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1342,13 +1342,13 @@ static bool isFoldedOrDeadInstruction(const Instruction *I,
!FuncInfo.isExportedInst(I); // Exported instrs must be computed.
}
-static void processDbgDeclare(FunctionLoweringInfo &FuncInfo,
+static bool processDbgDeclare(FunctionLoweringInfo &FuncInfo,
const Value *Address, DIExpression *Expr,
DILocalVariable *Var, DebugLoc DbgLoc) {
if (!Address) {
LLVM_DEBUG(dbgs() << "processDbgDeclares skipping " << *Var
<< " (bad address)\n");
- return;
+ return false;
}
MachineFunction *MF = FuncInfo.MF;
const DataLayout &DL = MF->getDataLayout();
@@ -1373,7 +1373,7 @@ static void processDbgDeclare(FunctionLoweringInfo &FuncInfo,
FI = FuncInfo.getArgumentFrameIndex(Arg);
if (FI == std::numeric_limits<int>::max())
- return;
+ return false;
if (Offset.getBoolValue())
Expr = DIExpression::prepend(Expr, DIExpression::ApplyOffset,
@@ -1383,18 +1383,17 @@ static void processDbgDeclare(FunctionLoweringInfo &FuncInfo,
<< ", Expr=" << *Expr << ", FI=" << FI
<< ", DbgLoc=" << DbgLoc << "\n");
MF->setVariableDbgInfo(Var, Expr, FI, DbgLoc);
+ return true;
}
/// Collect llvm.dbg.declare information. This is done after argument lowering
/// in case the declarations refer to arguments.
static void processDbgDeclares(FunctionLoweringInfo &FuncInfo) {
- for (const BasicBlock &BB : *FuncInfo.Fn) {
- for (const Instruction &I : BB) {
- if (const DbgDeclareInst *DI = dyn_cast<DbgDeclareInst>(&I)) {
- processDbgDeclare(FuncInfo, DI->getAddress(), DI->getExpression(),
- DI->getVariable(), DI->getDebugLoc());
- }
- }
+ for (const auto &I : instructions(*FuncInfo.Fn)) {
+ const auto *DI = dyn_cast<DbgDeclareInst>(&I);
+ if (DI && processDbgDeclare(FuncInfo, DI->getAddress(), DI->getExpression(),
+ DI->getVariable(), DI->getDebugLoc()))
+ FuncInfo.PreprocessedDbgDeclares.insert(DI);
}
}
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