[CodeGen][NPM] Differentiate pipeline-required and opt-required passes (#135752)

"Required" passes relate to actually running the pass on the IR,
regardless of whether they are in the pipeline.

CGPassBuilder was mistakenly still adding them to the pipeline.

The test `llc -stop-after=greedy -enable-new-pm` would still add
`greedy` to the pipeline otherwise.

Author: optimisan

llvm/include/llvm/Passes/CodeGenPassBuilder.h

@@ -188,9 +188,6 @@ 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 &>()));
@@ -214,14 +211,12 @@ template <typename DerivedT, typename TargetMachineT> class CodeGenPassBuilder {
     ~AddIRPass() { flushFPMToMPM(); }
 
     template <typename PassT>
-    void operator()(PassT &&Pass, StringRef Name = PassT::name()) {
+    void operator()(PassT &&Pass, bool Force = false,
+                    StringRef Name = PassT::name()) {
       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 (!Force && !PB.runBeforeAdding(Name))
         return;
 
       // Add Function Pass
@@ -625,9 +620,12 @@ Error CodeGenPassBuilder<Derived, TargetMachineT>::buildPipeline(
 
   {
     AddIRPass addIRPass(MPM, derived());
-    addIRPass(RequireAnalysisPass<MachineModuleAnalysis, Module>());
-    addIRPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
-    addIRPass(RequireAnalysisPass<CollectorMetadataAnalysis, Module>());
+    addIRPass(RequireAnalysisPass<MachineModuleAnalysis, Module>(),
+              /*Force=*/true);
+    addIRPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>(),
+              /*Force=*/true);
+    addIRPass(RequireAnalysisPass<CollectorMetadataAnalysis, Module>(),
+              /*Force=*/true);
     addISelPasses(addIRPass);
   }
 
@@ -743,7 +741,7 @@ void CodeGenPassBuilder<Derived, TargetMachineT>::addIRPasses(
   // Before running any passes, run the verifier to determine if the input
   // coming from the front-end and/or optimizer is valid.
   if (!Opt.DisableVerify)
-    addPass(VerifierPass());
+    addPass(VerifierPass(), /*Force=*/true);
 
   // Run loop strength reduction before anything else.
   if (getOptLevel() != CodeGenOptLevel::None && !Opt.DisableLSR) {
@@ -883,7 +881,7 @@ void CodeGenPassBuilder<Derived, TargetMachineT>::addISelPrepare(
   // All passes which modify the LLVM IR are now complete; run the verifier
   // to ensure that the IR is valid.
   if (!Opt.DisableVerify)
-    addPass(VerifierPass());
+    addPass(VerifierPass(), /*Force=*/true);
 }
 
 template <typename Derived, typename TargetMachineT>

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

@@ -2147,7 +2147,8 @@ void AMDGPUCodeGenPassBuilder::addPreISel(AddIRPass &addPass) const {
 
   // FIXME: Why isn't this queried as required from AMDGPUISelDAGToDAG, and why
   // isn't this in addInstSelector?
-  addPass(RequireAnalysisPass<UniformityInfoAnalysis, Function>());
+  addPass(RequireAnalysisPass<UniformityInfoAnalysis, Function>(),
+          /*Force=*/true);
 }
 
 void AMDGPUCodeGenPassBuilder::addILPOpts(AddMachinePass &addPass) const {

llvm/test/tools/llc/new-pm/pipeline.mir

@@ -1,5 +1,6 @@
 # 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 same nested pass managers
 # RUN: llc -mtriple=x86_64-pc-linux-gnu -x mir \
@@ -10,6 +11,7 @@
 
 # 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>
 
 # NESTED: function(machine-function(machine-cp))

llvm/test/tools/llc/new-pm/start-stop.ll

@@ -1,5 +1,5 @@
 ; RUN: llc -mtriple=x86_64-pc-linux-gnu -enable-new-pm -print-pipeline-passes -start-before=mergeicmps -stop-after=gc-lowering -filetype=null %s | FileCheck --match-full-lines %s --check-prefix=NULL
 ; RUN: llc -mtriple=x86_64-pc-linux-gnu -enable-new-pm -print-pipeline-passes -start-before=mergeicmps -stop-after=gc-lowering -o /dev/null %s | FileCheck --match-full-lines %s --check-prefix=OBJ
 
-; NULL: require<MachineModuleAnalysis>,require<profile-summary>,require<collector-metadata>,function(verify,loop-mssa(loop-reduce),mergeicmps,expand-memcmp,gc-lowering,ee-instrument<post-inline>,verify)
-; OBJ: require<MachineModuleAnalysis>,require<profile-summary>,require<collector-metadata>,function(verify,loop-mssa(loop-reduce),mergeicmps,expand-memcmp,gc-lowering,ee-instrument<post-inline>,verify),PrintMIRPreparePass,function(machine-function(print),invalidate<machine-function-info>)
+; NULL: require<MachineModuleAnalysis>,require<profile-summary>,require<collector-metadata>,function(verify,mergeicmps,expand-memcmp,gc-lowering,verify)
+; OBJ: require<MachineModuleAnalysis>,require<profile-summary>,require<collector-metadata>,function(verify,mergeicmps,expand-memcmp,gc-lowering,verify),PrintMIRPreparePass,function(machine-function(print),invalidate<machine-function-info>)