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

[via llvm-commits]

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@@ -0,0 +1,114 @@
+//===- 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() || 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);
+}
+
+struct CollectHashInfo {
+  uint64_t Offset;
+  uint64_t OpcodeHash;
+  uint64_t InstrHash;
+  uint64_t NeighborHash;
+};
+
+bool MachineBlockHashInfo::runOnMachineFunction(MachineFunction &F) {
+  DenseMap<const MachineBasicBlock *, CollectHashInfo> HashInfos;
+  uint16_t Offset = 0;
+  // Initialize hash components
+  for (const MachineBasicBlock &MBB : F) {
+    // offset of the machine basic block
+    HashInfos[&MBB].Offset = Offset;
+    Offset += MBB.size();
+    // Hashing opcodes
+    HashInfos[&MBB].OpcodeHash = hashBlock(MBB, /*HashOperands=*/false);
+    // Hash complete instructions
+    HashInfos[&MBB].InstrHash = hashBlock(MBB, /*HashOperands=*/true);
+  }
+
+  // Initialize neighbor hash
+  for (const MachineBasicBlock &MBB : F) {
+    uint64_t Hash = HashInfos[&MBB].OpcodeHash;
+    // Append hashes of successors
+    for (const MachineBasicBlock *SuccMBB : MBB.successors()) {
+      uint64_t SuccHash = HashInfos[SuccMBB].OpcodeHash;
+      Hash = hashing::detail::hash_16_bytes(Hash, SuccHash);
+    }
+    // Append hashes of predecessors
+    for (const MachineBasicBlock *PredMBB : MBB.predecessors()) {
+      uint64_t PredHash = HashInfos[PredMBB].OpcodeHash;
+      Hash = hashing::detail::hash_16_bytes(Hash, PredHash);
+    }
+    HashInfos[&MBB].NeighborHash = Hash;
+  }
+
+  // Assign hashes
+  for (const MachineBasicBlock &MBB : F) {
+    BlendedBlockHash BlendedHash(fold_64_to_16(HashInfos[&MBB].Offset),
----------------
wdx727 wrote:

Done. We use the variable name `HashInfo` due to a naming conflict between `MBBHashInfo` and our member variables.

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