[llvm] Adding Matching and Inference Functionality to Propeller-PR2 (PR #162963)

[via llvm-commits]

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+//===- llvm/CodeGen/MachineBlockHashInfo.cpp---------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Compute the hashes of basic blocks.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachineBlockHashInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Target/TargetMachine.h"
+
+using namespace llvm;
+
+uint64_t hashBlock(const MachineBasicBlock &MBB, bool HashOperands) {
+  uint64_t Hash = 0;
+  for (const MachineInstr &MI : MBB) {
+    if (MI.isMetaInstruction())
+      continue;
+    // Ignore terminator instruction
+    if (MI.isTerminator())
+      continue;
+    Hash = hashing::detail::hash_16_bytes(Hash, MI.getOpcode());
+    if (HashOperands) {
+      for (unsigned i = 0; i < MI.getNumOperands(); i++) {
+        Hash =
+            hashing::detail::hash_16_bytes(Hash, hash_value(MI.getOperand(i)));
+      }
+    }
+  }
+  return Hash;
+}
+
+/// Fold a 64-bit integer to a 16-bit one.
+uint16_t fold_64_to_16(const uint64_t Value) {
+  uint16_t Res = static_cast<uint16_t>(Value);
+  Res ^= static_cast<uint16_t>(Value >> 16);
+  Res ^= static_cast<uint16_t>(Value >> 32);
+  Res ^= static_cast<uint16_t>(Value >> 48);
+  return Res;
+}
+
+INITIALIZE_PASS(MachineBlockHashInfo, "machine-block-hash",
+                "Machine Block Hash Analysis", true, true)
+
+char MachineBlockHashInfo::ID = 0;
+
+MachineBlockHashInfo::MachineBlockHashInfo() : MachineFunctionPass(ID) {
+  initializeMachineBlockHashInfoPass(*PassRegistry::getPassRegistry());
+}
+
+void MachineBlockHashInfo::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  MachineFunctionPass::getAnalysisUsage(AU);
+}
+
+bool MachineBlockHashInfo::runOnMachineFunction(MachineFunction &F) {
+  DenseMap<MachineBasicBlock *, uint64_t> Offsets;
+  DenseMap<MachineBasicBlock *, uint64_t> OpcodeHashes;
+  DenseMap<MachineBasicBlock *, uint64_t> InstrHashes;
+  DenseMap<MachineBasicBlock *, uint64_t> NeighborHashes;
+  uint16_t Offset = 0;
+  // Initialize hash components
+  for (MachineBasicBlock &MBB : F) {
+    // offset of the machine basic block
+    Offsets[&MBB] = Offset;
+    Offset += MBB.size();
+    // Hashing opcodes
+    OpcodeHashes[&MBB] = hashBlock(MBB, false);
+    // Hash complete instructions
+    InstrHashes[&MBB] = hashBlock(MBB, true);
+  }
+
+  // Initialize neighbor hash
+  for (MachineBasicBlock &MBB : F) {
+    uint64_t Hash = OpcodeHashes[&MBB];
+    // Append hashes of successors
+    for (MachineBasicBlock *SuccMBB : MBB.successors()) {
+      uint64_t SuccHash = OpcodeHashes[SuccMBB];
+      Hash = hashing::detail::hash_16_bytes(Hash, SuccHash);
+    }
+    // Append hashes of predecessors
+    for (MachineBasicBlock *PredMBB : MBB.predecessors()) {
+      uint64_t PredHash = OpcodeHashes[PredMBB];
+      Hash = hashing::detail::hash_16_bytes(Hash, PredHash);
+    }
+    NeighborHashes[&MBB] = Hash;
+  }
+
+  // Assign hashes
+  for (MachineBasicBlock &MBB : F) {
+    if (MBB.getBBID()) {
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wdx727 wrote:

Done.

https://github.com/llvm/llvm-project/pull/162963