[llvm] [AMDGPU] Remove "amdgpu-enable-structurizer-workarounds" flag (PR #105819)

[Juan Manuel Martinez Caamaño via llvm-commits]

https://github.com/jmmartinez updated https://github.com/llvm/llvm-project/pull/105819

>From 3335d9ccd1bc6e0d5340e094ccc6012bfc285b39 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Fri, 23 Aug 2024 14:12:05 +0200
Subject: [PATCH] [AMDGPU] Remove "amdgpu-enable-structurizer-workarounds" flag

---
 .../lib/Target/AMDGPU/AMDGPUTargetMachine.cpp | 23 ++++---------------
 llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h  |  1 -
 2 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index 7a9735790371a1..7ac7b3315bb972 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -338,12 +338,6 @@ static cl::opt<bool> EnableScalarIRPasses(
   cl::init(true),
   cl::Hidden);
 
-static cl::opt<bool, true> EnableStructurizerWorkarounds(
-    "amdgpu-enable-structurizer-workarounds",
-    cl::desc("Enable workarounds for the StructurizeCFG pass"),
-    cl::location(AMDGPUTargetMachine::EnableStructurizerWorkarounds),
-    cl::init(true), cl::Hidden);
-
 static cl::opt<bool, true> EnableLowerModuleLDS(
     "amdgpu-enable-lower-module-lds", cl::desc("Enable lower module lds pass"),
     cl::location(AMDGPUTargetMachine::EnableLowerModuleLDS), cl::init(true),
@@ -615,7 +609,6 @@ AMDGPUTargetMachine::AMDGPUTargetMachine(const Target &T, const Triple &TT,
 
 bool AMDGPUTargetMachine::EnableFunctionCalls = false;
 bool AMDGPUTargetMachine::EnableLowerModuleLDS = true;
-bool AMDGPUTargetMachine::EnableStructurizerWorkarounds = true;
 
 AMDGPUTargetMachine::~AMDGPUTargetMachine() = default;
 
@@ -1231,10 +1224,8 @@ bool GCNPassConfig::addPreISel() {
   // Merge divergent exit nodes. StructurizeCFG won't recognize the multi-exit
   // regions formed by them.
   addPass(&AMDGPUUnifyDivergentExitNodesID);
-  if (EnableStructurizerWorkarounds) {
-    addPass(createFixIrreduciblePass());
-    addPass(createUnifyLoopExitsPass());
-  }
+  addPass(createFixIrreduciblePass());
+  addPass(createUnifyLoopExitsPass());
   addPass(createStructurizeCFGPass(false)); // true -> SkipUniformRegions
 
   addPass(createAMDGPUAnnotateUniformValuesLegacy());
@@ -1853,8 +1844,6 @@ void AMDGPUCodeGenPassBuilder::addCodeGenPrepare(AddIRPass &addPass) const {
 }
 
 void AMDGPUCodeGenPassBuilder::addPreISel(AddIRPass &addPass) const {
-  const bool EnableStructurizerWorkarounds =
-      AMDGPUTargetMachine::EnableStructurizerWorkarounds;
 
   if (TM.getOptLevel() > CodeGenOptLevel::None)
     addPass(FlattenCFGPass());
@@ -1868,12 +1857,8 @@ void AMDGPUCodeGenPassBuilder::addPreISel(AddIRPass &addPass) const {
   // regions formed by them.
 
   addPass(AMDGPUUnifyDivergentExitNodesPass());
-
-  if (EnableStructurizerWorkarounds) {
-    addPass(FixIrreduciblePass());
-    addPass(UnifyLoopExitsPass());
-  }
-
+  addPass(FixIrreduciblePass());
+  addPass(UnifyLoopExitsPass());
   addPass(StructurizeCFGPass(/*SkipUniformRegions=*/false));
 
   addPass(AMDGPUAnnotateUniformValuesPass());
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
index 66dfd2f733e3e9..5b7257ddb36f1e 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
@@ -38,7 +38,6 @@ class AMDGPUTargetMachine : public LLVMTargetMachine {
 public:
   static bool EnableFunctionCalls;
   static bool EnableLowerModuleLDS;
-  static bool EnableStructurizerWorkarounds;
 
   AMDGPUTargetMachine(const Target &T, const Triple &TT, StringRef CPU,
                       StringRef FS, const TargetOptions &Options,