[llvm-reduce] Add delta pass to run IR passes

[aeubanks]

Summary

The exact IR passes run is customizable via -ir-passes.

[aeubanks]

license formatting

[arsenm]

I'm not sure how useful running *all* passes is as a reduction strategy. I think an option to run specific passes would be more useful. For example I get a lot of mileage out of running InferAddressSpaces on testcases I'm reducing, most of which are extremely sensitive to IR changes and are easily hidden by running all optimizations

[aeubanks]

update

[regehr]

llvm/tools/llvm-reduce/deltas/RunIRPasses.cpp

21

put SROA at the start of this list?

I'd also argue for SCCP and DCE but I don't feel that strongly about it

[aeubanks]

add sroa

[regehr]

LGTM but happy to wait for Matt's view.

I like putting the oracle check in a callback, very cute!

[regehr]

LGTM

llvm/test/tools/llvm-reduce/run-ir-passes.ll

+; RUN: llvm-reduce --delta-passes=ir-passes --test FileCheck --test-arg --check-prefixes=CHECK-INTERESTINGNESS --test-arg %s --test-arg --input-file %s -o %t
+; RUN: FileCheck --check-prefixes=CHECK-FINAL --input-file=%t %s
+
+; CHECK-INTERESTINGNESS-LABEL: @f1
+; CHECK-INTERESTINGNESS: add
+; CHECK-INTERESTINGNESS-LABEL: @f2
+; CHECK-INTERESTINGNESS: add
+; CHECK-INTERESTINGNESS: add
+
+; CHECK-FINAL-LABEL: @f1
+; CHECK-FINAL: add i32 %a, 10
+; CHECK-FINAL-LABEL: @f2
+; CHECK-FINAL: add i32 %a, 5
+; CHECK-FINAL: add i32 %b, 5
+
+define i32 @f1(i32 %a) {
+  %b = add i32 %a, 5
+  %c = add i32 %b, 5
+  ret i32 %c
+}
+
+define i32 @f2(i32 %a) {
+  %b = add i32 %a, 5
+  %c = add i32 %b, 5
+  ret i32 %c
+}
+
+declare void @f3()
 No newline at end of file

llvm/tools/llvm-reduce/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   AllTargetsAsmParsers
   AllTargetsCodeGens
   AllTargetsDescs
   AllTargetsInfos
   Analysis
   BitReader
   BitWriter
   CodeGen
   Core
   IRReader
   MC
   MIRParser
+  Passes
   Support
   Target
   TransformUtils
   IPO
   )
 
 add_llvm_tool(llvm-reduce
   DeltaManager.cpp
add_llvm_tool(llvm-reduce
   deltas/ReduceOperandsToArgs.cpp
   deltas/ReduceInstructionsMIR.cpp
   deltas/ReduceInstructionFlagsMIR.cpp
   deltas/ReduceIRReferences.cpp
   deltas/ReduceVirtualRegisters.cpp
   deltas/ReduceRegisterMasks.cpp
   deltas/ReduceRegisterDefs.cpp
   deltas/ReduceRegisterUses.cpp
+  deltas/RunIRPasses.cpp
   deltas/SimplifyInstructions.cpp
   llvm-reduce.cpp
 
   DEPENDS
   intrinsics_gen
   )

llvm/tools/llvm-reduce/DeltaManager.cpp

 #include "deltas/ReduceOperands.h"
 #include "deltas/ReduceOperandsSkip.h"
 #include "deltas/ReduceOperandsToArgs.h"
 #include "deltas/ReduceRegisterDefs.h"
 #include "deltas/ReduceRegisterMasks.h"
 #include "deltas/ReduceRegisterUses.h"
 #include "deltas/ReduceSpecialGlobals.h"
 #include "deltas/ReduceVirtualRegisters.h"
+#include "deltas/RunIRPasses.h"
 #include "deltas/SimplifyInstructions.h"
 #include "llvm/Support/CommandLine.h"
 
 using namespace llvm;
 
 extern cl::OptionCategory LLVMReduceOptions;
 static cl::opt<std::string>
     DeltaPasses("delta-passes",
do {                                                                         \
     DELTA_PASS("global-values", reduceGlobalValuesDeltaPass)                   \
     DELTA_PASS("global-objects", reduceGlobalObjectsDeltaPass)                 \
     DELTA_PASS("global-initializers", reduceGlobalsInitializersDeltaPass)      \
     DELTA_PASS("global-variables", reduceGlobalsDeltaPass)                     \
     DELTA_PASS("metadata", reduceMetadataDeltaPass)                            \
     DELTA_PASS("arguments", reduceArgumentsDeltaPass)                          \
     DELTA_PASS("instructions", reduceInstructionsDeltaPass)                    \
     DELTA_PASS("simplify-instructions", simplifyInstructionsDeltaPass)         \
+    DELTA_PASS("ir-passes", runIRPassesDeltaPass)                              \
     DELTA_PASS("operands-zero", reduceOperandsZeroDeltaPass)                   \
     DELTA_PASS("operands-one", reduceOperandsOneDeltaPass)                     \
     DELTA_PASS("operands-nan", reduceOperandsNaNDeltaPass)                     \
     DELTA_PASS("operands-to-args", reduceOperandsToArgsDeltaPass)              \
     DELTA_PASS("operands-skip", reduceOperandsSkipDeltaPass)                   \
     DELTA_PASS("operand-bundles", reduceOperandBundesDeltaPass)                \
     DELTA_PASS("attributes", reduceAttributesDeltaPass)                        \
     DELTA_PASS("module-data", reduceModuleDataDeltaPass)                       \

llvm/tools/llvm-reduce/deltas/RunIRPasses.h

+//===- RunIRPasses.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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_LLVM_REDUCE_DELTAS_RUNPASSES_H
+#define LLVM_TOOLS_LLVM_REDUCE_DELTAS_RUNPASSES_H
+
+#include "Delta.h"
+
+namespace llvm {
+void runIRPassesDeltaPass(TestRunner &Test);
+} // namespace llvm
+
+#endif

llvm/tools/llvm-reduce/deltas/RunIRPasses.cpp

+//===- RunIRPasses.cpp ----------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "RunIRPasses.h"
+#include "Delta.h"
+#include "llvm/Passes/PassBuilder.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace llvm;
+
+static cl::opt<std::string> PassPipeline(
+    "ir-passes",
+    cl::desc("A textual description of the pass pipeline, same as "
+             "what's passed to `opt -passes`."),
+    cl::init("function(instcombine,gvn,simplifycfg,infer-address-spaces)"));
+
+static void runPasses(Oracle &O, Module &Program) {
+  LoopAnalysisManager LAM;
+  FunctionAnalysisManager FAM;
+  CGSCCAnalysisManager CGAM;
+  ModuleAnalysisManager MAM;
+
+  PassInstrumentationCallbacks PIC;
+  PIC.registerShouldRunOptionalPassCallback(
+      [&](StringRef, Any) { return !O.shouldKeep(); });
+  PassBuilder PB(nullptr, PipelineTuningOptions(), None, &PIC);
+
+  PB.registerModuleAnalyses(MAM);
+  PB.registerCGSCCAnalyses(CGAM);
+  PB.registerFunctionAnalyses(FAM);
+  PB.registerLoopAnalyses(LAM);
+  PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
+
+  ModulePassManager MPM;
+  if (auto Err = PB.parsePassPipeline(MPM, PassPipeline)) {
+    errs() << toString(std::move(Err)) << "\n";
+    report_fatal_error("Error constructing pass pipeline");
+  }
+  MPM.run(Program, MAM);
+}
+
+void llvm::runIRPassesDeltaPass(TestRunner &Test) {
+  errs() << "*** Running passes ...\n";
+  runDeltaPass(Test, runPasses);
+  errs() << "----------------------------\n";
+}

llvm/utils/gn/secondary/llvm/tools/llvm-reduce/BUILD.gn

 executable("llvm-reduce") {
   deps = [
     "//llvm/lib/CodeGen/MIRParser",
     "//llvm/lib/IR",
     "//llvm/lib/IRReader",
+    "//llvm/lib/Passes",
     "//llvm/lib/Support",
     "//llvm/lib/Target",
     "//llvm/lib/Target:TargetsToBuild",
     "//llvm/lib/Transforms/IPO",
     "//llvm/lib/Transforms/Utils",
   ]
   include_dirs = [ "." ]
   sources = [
sources = [
     "deltas/ReduceOperands.cpp",
     "deltas/ReduceOperandsSkip.cpp",
     "deltas/ReduceOperandsToArgs.cpp",
     "deltas/ReduceRegisterDefs.cpp",
     "deltas/ReduceRegisterMasks.cpp",
     "deltas/ReduceRegisterUses.cpp",
     "deltas/ReduceSpecialGlobals.cpp",
     "deltas/ReduceVirtualRegisters.cpp",
+    "deltas/RunIRPasses.cpp",
     "deltas/SimplifyInstructions.cpp",
     "deltas/Utils.cpp",
     "llvm-reduce.cpp",
   ]
 }