[llvm] [CodeGen][NPM] Do not add required passes to pipeline (PR #135752)

[Akshat Oke via llvm-commits]

https://github.com/optimisan created https://github.com/llvm/llvm-project/pull/135752

None

>From b753440d121819a4b69a8f614a8335a3d2229020 Mon Sep 17 00:00:00 2001
From: Akshat Oke <Akshat.Oke at amd.com>
Date: Tue, 15 Apr 2025 06:34:55 +0000
Subject: [PATCH] [CodeGen][NPM] Do not add required passes to pipeline

---
 llvm/include/llvm/Passes/CodeGenPassBuilder.h | 8 +-------
 llvm/test/tools/llc/new-pm/pipeline.mir       | 2 ++
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/llvm/include/llvm/Passes/CodeGenPassBuilder.h b/llvm/include/llvm/Passes/CodeGenPassBuilder.h
index ab9e7b2d23b9f..8f0fc98f4a9c8 100644
--- a/llvm/include/llvm/Passes/CodeGenPassBuilder.h
+++ b/llvm/include/llvm/Passes/CodeGenPassBuilder.h
@@ -182,9 +182,6 @@ template <typename DerivedT, typename TargetMachineT> class CodeGenPassBuilder {
   }
 
 protected:
-  template <typename PassT>
-  using has_required_t = decltype(std::declval<PassT &>().isRequired());
-
   template <typename PassT>
   using is_module_pass_t = decltype(std::declval<PassT &>().run(
       std::declval<Module &>(), std::declval<ModuleAnalysisManager &>()));
@@ -215,10 +212,7 @@ template <typename DerivedT, typename TargetMachineT> class CodeGenPassBuilder {
       static_assert((is_detected<is_function_pass_t, PassT>::value ||
                      is_detected<is_module_pass_t, PassT>::value) &&
                     "Only module pass and function pass are supported.");
-      bool Required = false;
-      if constexpr (is_detected<has_required_t, PassT>::value)
-        Required = PassT::isRequired();
-      if (!PB.runBeforeAdding(Name) && !Required)
+      if (!PB.runBeforeAdding(Name))
         return;
 
       // Add Function Pass
diff --git a/llvm/test/tools/llc/new-pm/pipeline.mir b/llvm/test/tools/llc/new-pm/pipeline.mir
index 761a3a424ee67..8f8e443923b7b 100644
--- a/llvm/test/tools/llc/new-pm/pipeline.mir
+++ b/llvm/test/tools/llc/new-pm/pipeline.mir
@@ -1,8 +1,10 @@
 # RUN: llc -mtriple=x86_64-pc-linux-gnu -x mir -passes=no-op-machine-function --print-pipeline-passes -filetype=null < %s | FileCheck %s --match-full-lines
 # RUN: llc -mtriple=x86_64-pc-linux-gnu -x mir -passes='require<machine-dom-tree>,print<machine-dom-tree>' -print-pipeline-passes < %s | FileCheck --check-prefix=ANALYSIS %s
+# RUN: llc -mtriple=x86_64-pc-linux-gnu -x mir -enable-new-pm -stop-before=greedy -O3 -filetype=null --print-pipeline-passes < %s | FileCheck %s --check-prefix=CHECK-REQ
 
 # CHECK: function(machine-function(no-op-machine-function)),PrintMIRPreparePass,function(machine-function(verify,print))
 
+# CHECK-REQ-NOT: greedy
 # ANALYSIS: require<machine-dom-tree>,print<machine-dom-tree>
 
 ---