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authorDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
committerDimitry Andric <dim@FreeBSD.org>2019-12-20 19:53:05 +0000
commit0b57cec536236d46e3dba9bd041533462f33dbb7 (patch)
tree56229dbdbbf76d18580f72f789003db17246c8d9 /contrib/llvm-project/llvm/lib/CodeGen/StackMapLivenessAnalysis.cpp
parent718ef55ec7785aae63f98f8ca05dc07ed399c16d (diff)
downloadsrc-0b57cec536236d46e3dba9bd041533462f33dbb7.tar.gz
src-0b57cec536236d46e3dba9bd041533462f33dbb7.zip
Move all sources from the llvm project into contrib/llvm-project.
This uses the new layout of the upstream repository, which was recently migrated to GitHub, and converted into a "monorepo". That is, most of the earlier separate sub-projects with their own branches and tags were consolidated into one top-level directory, and are now branched and tagged together. Updating the vendor area to match this layout is next.
Notes
Notes: svn path=/head/; revision=355940
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+//===-- StackMapLivenessAnalysis.cpp - StackMap live Out Analysis ----------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the StackMap Liveness analysis pass. The pass calculates
+// the liveness for each basic block in a function and attaches the register
+// live-out information to a stackmap or patchpoint intrinsic if present.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/LivePhysRegs.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "stackmaps"
+
+static cl::opt<bool> EnablePatchPointLiveness(
+ "enable-patchpoint-liveness", cl::Hidden, cl::init(true),
+ cl::desc("Enable PatchPoint Liveness Analysis Pass"));
+
+STATISTIC(NumStackMapFuncVisited, "Number of functions visited");
+STATISTIC(NumStackMapFuncSkipped, "Number of functions skipped");
+STATISTIC(NumBBsVisited, "Number of basic blocks visited");
+STATISTIC(NumBBsHaveNoStackmap, "Number of basic blocks with no stackmap");
+STATISTIC(NumStackMaps, "Number of StackMaps visited");
+
+namespace {
+/// This pass calculates the liveness information for each basic block in
+/// a function and attaches the register live-out information to a patchpoint
+/// intrinsic if present.
+///
+/// This pass can be disabled via the -enable-patchpoint-liveness=false flag.
+/// The pass skips functions that don't have any patchpoint intrinsics. The
+/// information provided by this pass is optional and not required by the
+/// aformentioned intrinsic to function.
+class StackMapLiveness : public MachineFunctionPass {
+ const TargetRegisterInfo *TRI;
+ LivePhysRegs LiveRegs;
+
+public:
+ static char ID;
+
+ /// Default construct and initialize the pass.
+ StackMapLiveness();
+
+ /// Tell the pass manager which passes we depend on and what
+ /// information we preserve.
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+ MachineFunctionProperties getRequiredProperties() const override {
+ return MachineFunctionProperties().set(
+ MachineFunctionProperties::Property::NoVRegs);
+ }
+
+ /// Calculate the liveness information for the given machine function.
+ bool runOnMachineFunction(MachineFunction &MF) override;
+
+private:
+ /// Performs the actual liveness calculation for the function.
+ bool calculateLiveness(MachineFunction &MF);
+
+ /// Add the current register live set to the instruction.
+ void addLiveOutSetToMI(MachineFunction &MF, MachineInstr &MI);
+
+ /// Create a register mask and initialize it with the registers from
+ /// the register live set.
+ uint32_t *createRegisterMask(MachineFunction &MF) const;
+};
+} // namespace
+
+char StackMapLiveness::ID = 0;
+char &llvm::StackMapLivenessID = StackMapLiveness::ID;
+INITIALIZE_PASS(StackMapLiveness, "stackmap-liveness",
+ "StackMap Liveness Analysis", false, false)
+
+/// Default construct and initialize the pass.
+StackMapLiveness::StackMapLiveness() : MachineFunctionPass(ID) {
+ initializeStackMapLivenessPass(*PassRegistry::getPassRegistry());
+}
+
+/// Tell the pass manager which passes we depend on and what information we
+/// preserve.
+void StackMapLiveness::getAnalysisUsage(AnalysisUsage &AU) const {
+ // We preserve all information.
+ AU.setPreservesAll();
+ AU.setPreservesCFG();
+ MachineFunctionPass::getAnalysisUsage(AU);
+}
+
+/// Calculate the liveness information for the given machine function.
+bool StackMapLiveness::runOnMachineFunction(MachineFunction &MF) {
+ if (!EnablePatchPointLiveness)
+ return false;
+
+ LLVM_DEBUG(dbgs() << "********** COMPUTING STACKMAP LIVENESS: "
+ << MF.getName() << " **********\n");
+ TRI = MF.getSubtarget().getRegisterInfo();
+ ++NumStackMapFuncVisited;
+
+ // Skip this function if there are no patchpoints to process.
+ if (!MF.getFrameInfo().hasPatchPoint()) {
+ ++NumStackMapFuncSkipped;
+ return false;
+ }
+ return calculateLiveness(MF);
+}
+
+/// Performs the actual liveness calculation for the function.
+bool StackMapLiveness::calculateLiveness(MachineFunction &MF) {
+ bool HasChanged = false;
+ // For all basic blocks in the function.
+ for (auto &MBB : MF) {
+ LLVM_DEBUG(dbgs() << "****** BB " << MBB.getName() << " ******\n");
+ LiveRegs.init(*TRI);
+ // FIXME: This should probably be addLiveOuts().
+ LiveRegs.addLiveOutsNoPristines(MBB);
+ bool HasStackMap = false;
+ // Reverse iterate over all instructions and add the current live register
+ // set to an instruction if we encounter a patchpoint instruction.
+ for (auto I = MBB.rbegin(), E = MBB.rend(); I != E; ++I) {
+ if (I->getOpcode() == TargetOpcode::PATCHPOINT) {
+ addLiveOutSetToMI(MF, *I);
+ HasChanged = true;
+ HasStackMap = true;
+ ++NumStackMaps;
+ }
+ LLVM_DEBUG(dbgs() << " " << LiveRegs << " " << *I);
+ LiveRegs.stepBackward(*I);
+ }
+ ++NumBBsVisited;
+ if (!HasStackMap)
+ ++NumBBsHaveNoStackmap;
+ }
+ return HasChanged;
+}
+
+/// Add the current register live set to the instruction.
+void StackMapLiveness::addLiveOutSetToMI(MachineFunction &MF,
+ MachineInstr &MI) {
+ uint32_t *Mask = createRegisterMask(MF);
+ MachineOperand MO = MachineOperand::CreateRegLiveOut(Mask);
+ MI.addOperand(MF, MO);
+}
+
+/// Create a register mask and initialize it with the registers from the
+/// register live set.
+uint32_t *StackMapLiveness::createRegisterMask(MachineFunction &MF) const {
+ // The mask is owned and cleaned up by the Machine Function.
+ uint32_t *Mask = MF.allocateRegMask();
+ for (auto Reg : LiveRegs)
+ Mask[Reg / 32] |= 1U << (Reg % 32);
+
+ // Give the target a chance to adjust the mask.
+ TRI->adjustStackMapLiveOutMask(Mask);
+
+ return Mask;
+}