Port Preserved[Module|Function]HashAnalysis to Analysis

[justinfargnoli]

The new IRNormalizer Pass (#113780) must invalidate Preserved[Module|Function]HashAnalysis. To invalidate the analyses, they must be made available to TransformUtils. TransformUtils depends on Analysis. Thus, port Preserved[Module|Function]HashAnalysis to Analysis.

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: Justin Fargnoli (justinfargnoli)

Changes

The new IRNormalizer Pass (#113780) must invalidate Preserved[Module|Function]HashAnalysis. To invalidate the analyses, they must be made available to TransformUtils. TransformUtils depends on Analysis. Thus, port Preserved[Module|Function]HashAnalysis to Analysis.

---

Full diff: https://github.com/llvm/llvm-project/pull/116108.diff

3 Files Affected:

• (modified) llvm/include/llvm/Analysis/StructuralHash.h (+32-1)
• (modified) llvm/lib/Analysis/StructuralHash.cpp (+9)
• (modified) llvm/lib/Passes/StandardInstrumentations.cpp (+1-35)

diff --git a/llvm/include/llvm/Analysis/StructuralHash.h b/llvm/include/llvm/Analysis/StructuralHash.h
index 4c9f063bc7d2c8..9ab13e43a3aa9d 100644
--- a/llvm/include/llvm/Analysis/StructuralHash.h
+++ b/llvm/include/llvm/Analysis/StructuralHash.h
@@ -1,4 +1,4 @@
-//=- StructuralHash.h - Structural Hash Printing --*- C++ -*-----------------=//
+//=- StructuralHash.h - Structural Hash Printing and Analysis --*- C++ -*----=//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,9 +10,40 @@
 #define LLVM_ANALYSIS_STRUCTURALHASH_H
 
 #include "llvm/IR/PassManager.h"
+#include "llvm/IR/StructuralHash.h"
 
 namespace llvm {
 
+struct PreservedFunctionHashAnalysis
+    : public AnalysisInfoMixin<PreservedFunctionHashAnalysis> {
+  static AnalysisKey Key;
+
+  struct FunctionHash {
+    uint64_t Hash;
+  };
+
+  using Result = FunctionHash;
+
+  Result run(Function &F, FunctionAnalysisManager &FAM) {
+    return Result{StructuralHash(F)};
+  }
+};
+
+struct PreservedModuleHashAnalysis
+    : public AnalysisInfoMixin<PreservedModuleHashAnalysis> {
+  static AnalysisKey Key;
+
+  struct ModuleHash {
+    uint64_t Hash;
+  };
+
+  using Result = ModuleHash;
+
+  Result run(Module &F, ModuleAnalysisManager &FAM) {
+    return Result{StructuralHash(F)};
+  }
+};
+
 enum class StructuralHashOptions {
   None,              /// Hash with opcode only.
   Detailed,          /// Hash with opcode and operands.
diff --git a/llvm/lib/Analysis/StructuralHash.cpp b/llvm/lib/Analysis/StructuralHash.cpp
index 4f2e003148b606..d03251cf9a6f02 100644
--- a/llvm/lib/Analysis/StructuralHash.cpp
+++ b/llvm/lib/Analysis/StructuralHash.cpp
@@ -8,6 +8,11 @@
 //
 // This file defines the StructuralHashPrinterPass which is used to show
 // the structural hash of all functions in a module and the module itself.
+// This file defines the StructuralHashPrinterPass and the
+// PreservedFunctionHashAnalysis and PreservedModuleHashAnalysis keys.
+//
+// The StructuralHashPrinterPass is used to show the structural hash of all
+// functions in a module and the module itself.
 //
 //===----------------------------------------------------------------------===//
 
@@ -18,6 +23,10 @@
 
 using namespace llvm;
 
+AnalysisKey PreservedFunctionHashAnalysis::Key;
+
+AnalysisKey PreservedModuleHashAnalysis::Key;
+
 PreservedAnalyses StructuralHashPrinterPass::run(Module &M,
                                                  ModuleAnalysisManager &MAM) {
   OS << "Module Hash: "
diff --git a/llvm/lib/Passes/StandardInstrumentations.cpp b/llvm/lib/Passes/StandardInstrumentations.cpp
index d4866a025c1b48..2d6aee0dab5f69 100644
--- a/llvm/lib/Passes/StandardInstrumentations.cpp
+++ b/llvm/lib/Passes/StandardInstrumentations.cpp
@@ -18,6 +18,7 @@
 #include "llvm/Analysis/CallGraphSCCPass.h"
 #include "llvm/Analysis/LazyCallGraph.h"
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/StructuralHash.h"
 #include "llvm/CodeGen/MIRPrinter.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
@@ -30,7 +31,6 @@
 #include "llvm/IR/PassInstrumentation.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/IR/PrintPasses.h"
-#include "llvm/IR/StructuralHash.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/CrashRecoveryContext.h"
@@ -1303,40 +1303,6 @@ struct PreservedCFGCheckerAnalysis
 
 AnalysisKey PreservedCFGCheckerAnalysis::Key;
 
-struct PreservedFunctionHashAnalysis
-    : public AnalysisInfoMixin<PreservedFunctionHashAnalysis> {
-  static AnalysisKey Key;
-
-  struct FunctionHash {
-    uint64_t Hash;
-  };
-
-  using Result = FunctionHash;
-
-  Result run(Function &F, FunctionAnalysisManager &FAM) {
-    return Result{StructuralHash(F)};
-  }
-};
-
-AnalysisKey PreservedFunctionHashAnalysis::Key;
-
-struct PreservedModuleHashAnalysis
-    : public AnalysisInfoMixin<PreservedModuleHashAnalysis> {
-  static AnalysisKey Key;
-
-  struct ModuleHash {
-    uint64_t Hash;
-  };
-
-  using Result = ModuleHash;
-
-  Result run(Module &F, ModuleAnalysisManager &FAM) {
-    return Result{StructuralHash(F)};
-  }
-};
-
-AnalysisKey PreservedModuleHashAnalysis::Key;
-
 bool PreservedCFGCheckerInstrumentation::CFG::invalidate(
     Function &F, const PreservedAnalyses &PA,
     FunctionAnalysisManager::Invalidator &) {

[nikic]

IRNormalizer needs to invalidate all analyses, not list specific ones to invalidate.

Effectively you're trying to suppress the error, by only invalidating exactly those analyses we use to detect missing analysis invalidation...

[justinfargnoli]

Thank you for the clarification @nikic!

My original thought process was that IRNormalizer should not make any semantic changes to the IR and thus should not invalidate any analyses besides the hashes.

However, it seems like the correct thought process is to be conservative and invalidate everything except CFG analyses because an analysis may depend on the syntactic structure of the IR. Am I on the right track here?

To address you're feedback I've added cd500d2 to the IRNormalizer PR and will close this one.