[llvm] [AMDGPU} Port AMDGPURewriteUndefForPHI to new pass manager (PR #66008)

[via llvm-commits]

https://github.com/jwanggit86 created https://github.com/llvm/llvm-project/pull/66008:

This patch ports the AMDGPURewriteUndefForPHI pass to the new pass manager. With this, the pass is supported under both the legacy and the new pass managers.

>From f2068b9d9faa6c08c70a5a07bcbaabf0fc358d29 Mon Sep 17 00:00:00 2001
From: Jun Wang <jun.wang7 at amd.com>
Date: Mon, 11 Sep 2023 15:25:42 -0500
Subject: [PATCH] [AMDGPU} Port AMDGPURewriteUndefForPHI to new pass manager

This patch ports the AMDGPURewriteUndefForPHI pass to the new pass
manager. With this, the pass is supported under both the legacy and
the new pass managers.
---
 llvm/lib/Target/AMDGPU/AMDGPU.h                    | 10 ++++++++++
 .../lib/Target/AMDGPU/AMDGPURewriteUndefForPHI.cpp | 14 ++++++++++++++
 llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp     |  4 ++++
 llvm/test/CodeGen/AMDGPU/rewrite-undef-for-phi.ll  |  1 +
 4 files changed, 29 insertions(+)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPU.h b/llvm/lib/Target/AMDGPU/AMDGPU.h
index 157a02ec31b2ec6..434943490caeab3 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPU.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPU.h
@@ -291,6 +291,16 @@ FunctionPass *createAMDGPURewriteUndefForPHIPass();
 void initializeAMDGPURewriteUndefForPHIPass(PassRegistry &);
 extern char &AMDGPURewriteUndefForPHIPassID;
 
+class AMDGPURewriteUndefForPHIPass
+    : public PassInfoMixin<AMDGPURewriteUndefForPHIPass> {
+private:
+  TargetMachine &TM;
+
+public:
+  AMDGPURewriteUndefForPHIPass(TargetMachine &TM) : TM(TM){};
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+};
+
 void initializeSIAnnotateControlFlowPass(PassRegistry&);
 extern char &SIAnnotateControlFlowPassID;
 
diff --git a/llvm/lib/Target/AMDGPU/AMDGPURewriteUndefForPHI.cpp b/llvm/lib/Target/AMDGPU/AMDGPURewriteUndefForPHI.cpp
index 9c07851243c9173..3e9625e954ea653 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPURewriteUndefForPHI.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPURewriteUndefForPHI.cpp
@@ -177,6 +177,20 @@ bool AMDGPURewriteUndefForPHI::runOnFunction(Function &F) {
   return rewritePHIs(F, UA, DT);
 }
 
+PreservedAnalyses
+AMDGPURewriteUndefForPHIPass::run(Function &F, FunctionAnalysisManager &AM) {
+  UniformityInfo &UA = AM.getResult<UniformityInfoAnalysis>(F);
+  DominatorTree *DT = &AM.getResult<DominatorTreeAnalysis>(F);
+  bool Changed = rewritePHIs(F, UA, DT);
+  if (Changed) {
+    PreservedAnalyses PA;
+    PA.preserveSet<CFGAnalyses>();
+    return PA;
+  }
+
+  return PreservedAnalyses::all();
+}
+
 FunctionPass *llvm::createAMDGPURewriteUndefForPHIPass() {
   return new AMDGPURewriteUndefForPHI();
 }
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index 991681dafedaad1..befa036ee32df14 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -663,6 +663,10 @@ void AMDGPUTargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
           PM.addPass(AMDGPULowerKernelArgumentsPass(*this));
           return true;
         }
+        if (PassName == "amdgpu-rewrite-undef-for-phi") {
+          PM.addPass(AMDGPURewriteUndefForPHIPass(*this));
+          return true;
+        }
         return false;
       });
 
diff --git a/llvm/test/CodeGen/AMDGPU/rewrite-undef-for-phi.ll b/llvm/test/CodeGen/AMDGPU/rewrite-undef-for-phi.ll
index c0f6c5ae0240a69..4f6b9f474c13171 100644
--- a/llvm/test/CodeGen/AMDGPU/rewrite-undef-for-phi.ll
+++ b/llvm/test/CodeGen/AMDGPU/rewrite-undef-for-phi.ll
@@ -1,5 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -mtriple=amdgcn-- -S -amdgpu-rewrite-undef-for-phi %s | FileCheck -check-prefix=OPT %s
+; RUN: opt -mtriple=amdgcn-- -S -passes=amdgpu-rewrite-undef-for-phi %s | FileCheck -check-prefix=OPT %s
 
 define amdgpu_ps float @basic(float inreg %c, i32 %x) #0 {
 ; OPT-LABEL: @basic(