[llvm] [llvm-diff] Add Commutativity on BinOp (PR #123314)

[Serval MARTINOT-LAGARDE via llvm-commits]

https://github.com/Serval6 updated https://github.com/llvm/llvm-project/pull/123314

>From 14030e2bdf8ee60c790d01e59f328d15c1f1496a Mon Sep 17 00:00:00 2001
From: Serval Martinot-Lagarde <serval.martinot-lagarde at sipearl.com>
Date: Thu, 16 Jan 2025 16:38:14 +0100
Subject: [PATCH] [llvm-diff] add optional call to IRNormalizer

---
 llvm/test/tools/llvm-diff/help.test        |  1 +
 llvm/test/tools/llvm-diff/ir-normalizer.ll | 29 ++++++++++++++++++++++
 llvm/tools/llvm-diff/CMakeLists.txt        |  2 ++
 llvm/tools/llvm-diff/llvm-diff.cpp         | 28 ++++++++++++++++++++-
 4 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 llvm/test/tools/llvm-diff/ir-normalizer.ll

diff --git a/llvm/test/tools/llvm-diff/help.test b/llvm/test/tools/llvm-diff/help.test
index 0440fa8c124ebe..b799b3a8c55881 100644
--- a/llvm/test/tools/llvm-diff/help.test
+++ b/llvm/test/tools/llvm-diff/help.test
@@ -2,4 +2,5 @@
 
 # HELP: USAGE
 # HELP: Color Options
+# HELP: Diff Options
 # HELP: Generic Options
diff --git a/llvm/test/tools/llvm-diff/ir-normalizer.ll b/llvm/test/tools/llvm-diff/ir-normalizer.ll
new file mode 100644
index 00000000000000..00ae3723e7469a
--- /dev/null
+++ b/llvm/test/tools/llvm-diff/ir-normalizer.ll
@@ -0,0 +1,29 @@
+; Check that commutative operations are considered equal after normalization when parameters are exchanged.
+;
+; Replace '%a, %b' with '%b, %a' in 'or' (commutative) and 'sub' (non-commutative) operations.
+;
+; RUN: rm -f %t.ll
+; RUN: cat %s | sed -e 's/^\(  .*\) i1 %a, %b$/\1 i1 %b, %a/' > %t.ll
+; RUN: not llvm-diff                        %s %t.ll 2>&1 | FileCheck %s --check-prefix DEFAULT
+; RUN: not llvm-diff --enable-ir-normalizer %s %t.ll 2>&1 | FileCheck %s --check-prefix NORMALIZE
+
+; DEFAULT:      in function choice:
+; DEFAULT-NEXT:   in block %entry:
+; DEFAULT-NEXT:     >   %0 = or i1 %b, %a
+; DEFAULT-NEXT:     >   %1 = sub i1 %b, %a
+; DEFAULT-NEXT:     >   ret i1 %0
+; DEFAULT-NEXT:     <   %0 = or i1 %a, %b
+; DEFAULT-NEXT:     <   %1 = sub i1 %a, %b
+; DEFAULT-NEXT:     <   ret i1 %0
+
+; NORMALIZE:      in function choice:
+; NORMALIZE-NEXT:   in block [[BB:%bb[0-9]+]]:
+; NORMALIZE-NEXT:     >   %0 = sub i1 %a1, %a0
+; NORMALIZE-NEXT:     <   %0 = sub i1 %a0, %a1
+
+define i1 @choice(i1 %a, i1 %b) {
+entry:
+  %0 = or i1 %a, %b
+  %1 = sub i1 %a, %b
+  ret i1 %0
+}
diff --git a/llvm/tools/llvm-diff/CMakeLists.txt b/llvm/tools/llvm-diff/CMakeLists.txt
index d2abab9719d9a8..48b48a5d353243 100644
--- a/llvm/tools/llvm-diff/CMakeLists.txt
+++ b/llvm/tools/llvm-diff/CMakeLists.txt
@@ -1,7 +1,9 @@
 set(LLVM_LINK_COMPONENTS
   Core
   IRReader
+  Passes
   Support
+  TransformUtils
   )
 
 add_llvm_tool(llvm-diff
diff --git a/llvm/tools/llvm-diff/llvm-diff.cpp b/llvm/tools/llvm-diff/llvm-diff.cpp
index 3e77b1ed89b048..e239ee5c16004c 100644
--- a/llvm/tools/llvm-diff/llvm-diff.cpp
+++ b/llvm/tools/llvm-diff/llvm-diff.cpp
@@ -17,11 +17,13 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IRReader/IRReader.h"
+#include "llvm/Passes/PassBuilder.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SourceMgr.h"
-#include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/WithColor.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/IRNormalizer.h"
 #include <string>
 #include <utility>
 
@@ -68,6 +70,10 @@ static cl::list<std::string> GlobalsToCompare(cl::Positional,
                                               cl::desc("<globals to compare>"),
                                               cl::cat(DiffCategory));
 
+static cl::opt<bool> EnableIRNormalizer("enable-ir-normalizer", cl::Optional,
+					cl::desc("Call IRNormalizer before diff"),
+					cl::cat(DiffCategory));
+
 int main(int argc, char **argv) {
   cl::HideUnrelatedOptions({&DiffCategory, &getColorCategory()});
   cl::ParseCommandLineOptions(argc, argv);
@@ -79,6 +85,26 @@ int main(int argc, char **argv) {
   std::unique_ptr<Module> RModule = readModule(Context, RightFilename);
   if (!LModule || !RModule) return 1;
 
+  if (EnableIRNormalizer) {
+    LoopAnalysisManager LAM;
+    FunctionAnalysisManager FAM;
+    CGSCCAnalysisManager CGAM;
+    ModuleAnalysisManager MAM;
+
+    PassBuilder PB;
+
+    PB.registerModuleAnalyses(MAM);
+    PB.registerCGSCCAnalyses(CGAM);
+    PB.registerFunctionAnalyses(FAM);
+    PB.registerLoopAnalyses(LAM);
+    PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
+
+    ModulePassManager PM;
+    PM.addPass(createModuleToFunctionPassAdaptor(IRNormalizerPass()));
+    PM.run(*LModule, MAM);
+    PM.run(*RModule, MAM);
+  }
+
   DiffConsumer Consumer;
   DifferenceEngine Engine(Consumer);