[Instrumentor] Add Instrumentor pass

This commit adds the basic infrastructure for the Instrumentor
pass, which allows instrumenting code in a simple and
customizable way. This commit adds support for instrumenting
load and store instructions. The Instrumentor can be configured
with a JSON file that describes what should be instrumented, or
can be used programmatically from another pass.

This is only a squash commit of several contributions to the
Instrumentor. The following are the authors and contributors of
this pass:

Co-authored-by: Johannes Doerfert <[email protected]>
Co-authored-by: Kevin Sala <[email protected]>
Co-authored-by: Ivan Radanov Ivanov <[email protected]>
Co-authored-by: Ethan Luis McDonough <[email protected]>

Author: 4 people

llvm/include/llvm/Transforms/IPO/Instrumentor.h

@@ -0,0 +1,29 @@
+//===- Transforms/IPO/InstrumentorConfigFile.h ----------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Utilities for the Instrumentor JSON configuration file.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_IPO_INSTRUMENTOR_CONFIGFILE_H
+#define LLVM_TRANSFORMS_IPO_INSTRUMENTOR_CONFIGFILE_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Transforms/IPO/Instrumentor.h"
+
+namespace llvm {
+namespace instrumentor {
+
+void writeConfigToJSON(InstrumentationConfig &IConf, StringRef OutputFile);
+
+bool readConfigFromJSON(InstrumentationConfig &IConf, StringRef InputFile);
+
+} // end namespace instrumentor
+} // end namespace llvm
+
+#endif // LLVM_TRANSFORMS_IPO_INSTRUMENTOR_CONFIGFILE_H

llvm/include/llvm/Transforms/IPO/InstrumentorConfigFile.h

@@ -221,6 +221,7 @@
 #include "llvm/Transforms/IPO/IROutliner.h"
 #include "llvm/Transforms/IPO/InferFunctionAttrs.h"
 #include "llvm/Transforms/IPO/Inliner.h"
+#include "llvm/Transforms/IPO/Instrumentor.h"
 #include "llvm/Transforms/IPO/Internalize.h"
 #include "llvm/Transforms/IPO/LoopExtractor.h"
 #include "llvm/Transforms/IPO/LowerTypeTests.h"

llvm/lib/Passes/PassBuilder.cpp

@@ -63,6 +63,7 @@
 #include "llvm/Transforms/IPO/IROutliner.h"
 #include "llvm/Transforms/IPO/InferFunctionAttrs.h"
 #include "llvm/Transforms/IPO/Inliner.h"
+#include "llvm/Transforms/IPO/Instrumentor.h"
 #include "llvm/Transforms/IPO/LowerTypeTests.h"
 #include "llvm/Transforms/IPO/MemProfContextDisambiguation.h"
 #include "llvm/Transforms/IPO/MergeFunctions.h"
@@ -212,6 +213,10 @@ static cl::opt<bool> EnableLoopFlatten("enable-loop-flatten", cl::init(false),
                                        cl::Hidden,
                                        cl::desc("Enable the LoopFlatten Pass"));
 
+static cl::opt<bool>
+    EnableInstrumentor("enable-instrumentor", cl::init(false), cl::Hidden,
+                       cl::desc("Enable the Instrumentor Pass"));
+
 // Experimentally allow loop header duplication. This should allow for better
 // optimization at Oz, since loop-idiom recognition can then recognize things
 // like memcpy. If this ends up being useful for many targets, we should drop
@@ -1594,6 +1599,10 @@ PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
 
   invokeOptimizerLastEPCallbacks(MPM, Level, LTOPhase);
 
+  // Run the Instrumentor pass late.
+  if (EnableInstrumentor)
+    MPM.addPass(InstrumentorPass());
+
   // Split out cold code. Splitting is done late to avoid hiding context from
   // other optimizations and inadvertently regressing performance. The tradeoff
   // is that this has a higher code size cost than splitting early.
@@ -2306,6 +2315,9 @@ PassBuilder::buildO0DefaultPipeline(OptimizationLevel Level,
 
   invokeOptimizerLastEPCallbacks(MPM, Level, Phase);
 
+  if (EnableInstrumentor)
+    MPM.addPass(InstrumentorPass());
+
   if (isLTOPreLink(Phase))
     addRequiredLTOPreLinkPasses(MPM);
 

llvm/lib/Passes/PassBuilderPipelines.cpp

@@ -94,6 +94,7 @@ MODULE_PASS("instrprof", InstrProfilingLoweringPass())
 MODULE_PASS("ctx-instr-lower", PGOCtxProfLoweringPass())
 MODULE_PASS("print<ctx-prof-analysis>", CtxProfAnalysisPrinterPass(errs()))
 MODULE_PASS("invalidate<all>", InvalidateAllAnalysesPass())
+MODULE_PASS("instrumentor", InstrumentorPass())
 MODULE_PASS("iroutliner", IROutlinerPass())
 MODULE_PASS("jmc-instrumenter", JMCInstrumenterPass())
 MODULE_PASS("lower-emutls", LowerEmuTLSPass())

llvm/lib/Passes/PassRegistry.def

@@ -27,6 +27,8 @@ add_llvm_component_library(LLVMipo
   IROutliner.cpp
   InferFunctionAttrs.cpp
   Inliner.cpp
+  Instrumentor.cpp
+  InstrumentorConfigFile.cpp
   Internalize.cpp
   LoopExtractor.cpp
   LowerTypeTests.cpp
@@ -62,6 +64,7 @@ add_llvm_component_library(LLVMipo
   BitReader
   BitWriter
   Core
+  Demangle
   FrontendOpenMP
   InstCombine
   IRReader