[CodeGen][NPM] Do not add required passes to pipeline

Author: optimisan

llvm/include/llvm/Passes/CodeGenPassBuilder.h

@@ -187,9 +187,6 @@ 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 &>()));
@@ -220,10 +217,7 @@ 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

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>
 
 ---