1 files changed, 133 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp b/contrib/llvm-project/llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp
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index 000000000000..40770b15aa35
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+++ b/contrib/llvm-project/llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp
@@ -0,0 +1,133 @@
+//===- LiveDebugValues.cpp - Tracking Debug Value MIs ---------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "LiveDebugValues.h"
+
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetMachine.h"
+
+/// \file LiveDebugValues.cpp
+///
+/// The LiveDebugValues pass extends the range of variable locations
+/// (specified by DBG_VALUE instructions) from single blocks to successors
+/// and any other code locations where the variable location is valid.
+/// There are currently two implementations: the "VarLoc" implementation
+/// explicitly tracks the location of a variable, while the "InstrRef"
+/// implementation tracks the values defined by instructions through locations.
+///
+/// This file implements neither; it merely registers the pass, allows the
+/// user to pick which implementation will be used to propagate variable
+/// locations.
+
+#define DEBUG_TYPE "livedebugvalues"
+
+using namespace llvm;
+
+static cl::opt<bool>
+    ForceInstrRefLDV("force-instr-ref-livedebugvalues", cl::Hidden,
+                     cl::desc("Use instruction-ref based LiveDebugValues with "
+                              "normal DBG_VALUE inputs"),
+                     cl::init(false));
+
+static cl::opt<cl::boolOrDefault> ValueTrackingVariableLocations(
+    "experimental-debug-variable-locations",
+    cl::desc("Use experimental new value-tracking variable locations"));
+
+// Options to prevent pathological compile-time behavior. If InputBBLimit and
+// InputDbgValueLimit are both exceeded, range extension is disabled.
+static cl::opt<unsigned> InputBBLimit(
+    "livedebugvalues-input-bb-limit",
+    cl::desc("Maximum input basic blocks before DBG_VALUE limit applies"),
+    cl::init(10000), cl::Hidden);
+static cl::opt<unsigned> InputDbgValueLimit(
+    "livedebugvalues-input-dbg-value-limit",
+    cl::desc(
+        "Maximum input DBG_VALUE insts supported by debug range extension"),
+    cl::init(50000), cl::Hidden);
+
+namespace {
+/// Generic LiveDebugValues pass. Calls through to VarLocBasedLDV or
+/// InstrRefBasedLDV to perform location propagation, via the LDVImpl
+/// base class.
+class LiveDebugValues : public MachineFunctionPass {
+public:
+  static char ID;
+
+  LiveDebugValues();
+  ~LiveDebugValues() {}
+
+  /// Calculate the liveness information for the given machine function.
+  bool runOnMachineFunction(MachineFunction &MF) override;
+
+  MachineFunctionProperties getRequiredProperties() const override {
+    return MachineFunctionProperties().set(
+        MachineFunctionProperties::Property::NoVRegs);
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesCFG();
+    MachineFunctionPass::getAnalysisUsage(AU);
+  }
+
+private:
+  std::unique_ptr<LDVImpl> InstrRefImpl;
+  std::unique_ptr<LDVImpl> VarLocImpl;
+  TargetPassConfig *TPC;
+  MachineDominatorTree MDT;
+};
+} // namespace
+
+char LiveDebugValues::ID = 0;
+
+char &llvm::LiveDebugValuesID = LiveDebugValues::ID;
+
+INITIALIZE_PASS(LiveDebugValues, DEBUG_TYPE, "Live DEBUG_VALUE analysis", false,
+                false)
+
+/// Default construct and initialize the pass.
+LiveDebugValues::LiveDebugValues() : MachineFunctionPass(ID) {
+  initializeLiveDebugValuesPass(*PassRegistry::getPassRegistry());
+  InstrRefImpl =
+      std::unique_ptr<LDVImpl>(llvm::makeInstrRefBasedLiveDebugValues());
+  VarLocImpl = std::unique_ptr<LDVImpl>(llvm::makeVarLocBasedLiveDebugValues());
+}
+
+bool LiveDebugValues::runOnMachineFunction(MachineFunction &MF) {
+  bool InstrRefBased = MF.useDebugInstrRef();
+  // Allow the user to force selection of InstrRef LDV.
+  InstrRefBased |= ForceInstrRefLDV;
+
+  TPC = getAnalysisIfAvailable<TargetPassConfig>();
+  LDVImpl *TheImpl = &*VarLocImpl;
+
+  MachineDominatorTree *DomTree = nullptr;
+  if (InstrRefBased) {
+    DomTree = &MDT;
+    MDT.calculate(MF);
+    TheImpl = &*InstrRefImpl;
+  }
+
+  return TheImpl->ExtendRanges(MF, DomTree, TPC, InputBBLimit,
+                               InputDbgValueLimit);
+}
+
+bool llvm::debuginfoShouldUseDebugInstrRef(const Triple &T) {
+  // Enable by default on x86_64, disable if explicitly turned off on cmdline.
+  if (T.getArch() == llvm::Triple::x86_64 &&
+      ValueTrackingVariableLocations != cl::boolOrDefault::BOU_FALSE)
+    return true;
+
+  // Enable if explicitly requested on command line.
+  return ValueTrackingVariableLocations == cl::boolOrDefault::BOU_TRUE;
+}