[OpenMP] Remove folding logic for removed runtime function

[jhuber6]

Summary

This function was removed from the device runtime at some point but we
still have specialized code for it and an entry in the runtime kinds.
Remove it as it is no longer necessary.

[tianshilei1992]

LG

llvm/include/llvm/Frontend/OpenMP/OMPKinds.def

 __OMP_RTL(__kmpc_parallel_level, false, Int8, )
 __OMP_RTL(__kmpc_is_spmd_exec_mode, false, Int8, )
 __OMP_RTL(__kmpc_barrier_simple_spmd, false, Void, IdentPtr, Int32)
 __OMP_RTL(__kmpc_barrier_simple_generic, false, Void, IdentPtr, Int32)
 
 __OMP_RTL(__kmpc_warp_active_thread_mask, false, Int64,)
 __OMP_RTL(__kmpc_syncwarp, false, Void, Int64)
 
-__OMP_RTL(__kmpc_is_generic_main_thread_id, false, Int8, Int32)
-
 __OMP_RTL(__last, false, Void, )
 
 #undef __OMP_RTL
 #undef OMP_RTL
 
 #define ParamAttrs(...) ArrayRef<AttributeSet>({__VA_ARGS__})
 #define EnumAttr(Kind) Attribute::get(Ctx, Attribute::AttrKind::Kind)
 #define EnumAttrInt(Kind, N) Attribute::get(Ctx, Attribute::AttrKind::Kind, N)

llvm/lib/Transforms/IPO/OpenMPOpt.cpp

struct AAFoldRuntimeCallCallSiteReturned : AAFoldRuntimeCall {
   }
 
   ChangeStatus updateImpl(Attributor &A) override {
     ChangeStatus Changed = ChangeStatus::UNCHANGED;
     switch (RFKind) {
     case OMPRTL___kmpc_is_spmd_exec_mode:
       Changed |= foldIsSPMDExecMode(A);
       break;
-    case OMPRTL___kmpc_is_generic_main_thread_id:
-      Changed |= foldIsGenericMainThread(A);
-      break;
     case OMPRTL___kmpc_parallel_level:
       Changed |= foldParallelLevel(A);
       break;
     case OMPRTL___kmpc_get_hardware_num_threads_in_block:
       Changed = Changed | foldKernelFnAttribute(A, "omp_target_thread_limit");
       break;
     case OMPRTL___kmpc_get_hardware_num_blocks:
       Changed = Changed | foldKernelFnAttribute(A, "omp_target_num_teams");
if (KnownSPMDCount || AssumedSPMDCount) {
       // must be none.
       assert(!SimplifiedValue && "SimplifiedValue should be none");
     }
 
     return SimplifiedValue == SimplifiedValueBefore ? ChangeStatus::UNCHANGED
                                                     : ChangeStatus::CHANGED;
   }
 
-  /// Fold __kmpc_is_generic_main_thread_id into a constant if possible.
-  ChangeStatus foldIsGenericMainThread(Attributor &A) {
-    std::optional<Value *> SimplifiedValueBefore = SimplifiedValue;
-
-    CallBase &CB = cast<CallBase>(getAssociatedValue());
-    Function *F = CB.getFunction();
-    const auto &ExecutionDomainAA = A.getAAFor<AAExecutionDomain>(
-        *this, IRPosition::function(*F), DepClassTy::REQUIRED);
-
-    if (!ExecutionDomainAA.isValidState())
-      return indicatePessimisticFixpoint();
-
-    auto &Ctx = getAnchorValue().getContext();
-    if (ExecutionDomainAA.isExecutedByInitialThreadOnly(CB))
-      SimplifiedValue = ConstantInt::get(Type::getInt8Ty(Ctx), true);
-    else
-      return indicatePessimisticFixpoint();
-
-    return SimplifiedValue == SimplifiedValueBefore ? ChangeStatus::UNCHANGED
-                                                    : ChangeStatus::CHANGED;
-  }
-
   /// Fold __kmpc_parallel_level into a constant if possible.
   ChangeStatus foldParallelLevel(Attributor &A) {
     std::optional<Value *> SimplifiedValueBefore = SimplifiedValue;
 
     auto &CallerKernelInfoAA = A.getAAFor<AAKernelInfo>(
         *this, IRPosition::function(*getAnchorScope()), DepClassTy::REQUIRED);
 
     if (!CallerKernelInfoAA.ParallelLevels.isValidState())

llvm/test/Transforms/OpenMP/fold_generic_main_thread.ll

-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature
-; RUN: opt -S -passes='openmp-opt' < %s | FileCheck %s
-; RUN: opt -openmp-opt-disable-folding -S -passes='openmp-opt' < %s | FileCheck %s --check-prefix=CHECK-DISABLED
-; ModuleID = 'single_threaded_exeuction.c'
-
-%struct.ident_t = type { i32, i32, i32, i32, i8* }
-
-@0 = private unnamed_addr constant [1 x i8] c"\00", align 1
-@1 = private unnamed_addr constant %struct.ident_t { i32 0, i32 2, i32 0, i32 0, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @0, i32 0, i32 0) }, align 8
-
-define void @kernel() {
-; CHECK-LABEL: define {{[^@]+}}@kernel() {
-; CHECK-NEXT:    [[CALL:%.*]] = call i32 @__kmpc_target_init(%struct.ident_t* nonnull @[[GLOB1:[0-9]+]], i8 1, i1 false)
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[CALL]], -1
-; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
-; CHECK:       if.then:
-; CHECK-NEXT:    call void @foo()
-; CHECK-NEXT:    br label [[IF_END:%.*]]
-; CHECK:       if.else:
-; CHECK-NEXT:    call void @bar()
-; CHECK-NEXT:    br label [[IF_END]]
-; CHECK:       if.end:
-; CHECK-NEXT:    call void @__kmpc_target_deinit(%struct.ident_t* null, i8 1)
-; CHECK-NEXT:    ret void
-;
-; CHECK-DISABLED-LABEL: define {{[^@]+}}@kernel() {
-; CHECK-DISABLED-NEXT:    [[CALL:%.*]] = call i32 @__kmpc_target_init(%struct.ident_t* nonnull @[[GLOB1:[0-9]+]], i8 1, i1 false)
-; CHECK-DISABLED-NEXT:    [[CMP:%.*]] = icmp eq i32 [[CALL]], -1
-; CHECK-DISABLED-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
-; CHECK-DISABLED:       if.then:
-; CHECK-DISABLED-NEXT:    call void @foo()
-; CHECK-DISABLED-NEXT:    br label [[IF_END:%.*]]
-; CHECK-DISABLED:       if.else:
-; CHECK-DISABLED-NEXT:    call void @bar()
-; CHECK-DISABLED-NEXT:    br label [[IF_END]]
-; CHECK-DISABLED:       if.end:
-; CHECK-DISABLED-NEXT:    call void @__kmpc_target_deinit(%struct.ident_t* null, i8 1)
-; CHECK-DISABLED-NEXT:    ret void
-;
-  %call = call i32 @__kmpc_target_init(%struct.ident_t* nonnull @1, i8 1, i1 false)
-  %cmp = icmp eq i32 %call, -1
-  br i1 %cmp, label %if.then, label %if.else
-if.then:
-  call void @foo()
-  br label %if.end
-if.else:
-  call void @bar()
-  br label %if.end
-if.end:
-  call void @__kmpc_target_deinit(%struct.ident_t* null, i8 1)
-  ret void
-}
-
-; Function Attrs: noinline
-define internal void @foo() {
-; CHECK-LABEL: define {{[^@]+}}@foo() {
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TID:%.*]] = call i32 @__kmpc_get_hardware_thread_id()
-; CHECK-NEXT:    br label [[IF_THEN:%.*]]
-; CHECK:       if.then:
-; CHECK-NEXT:    call void @baz()
-; CHECK-NEXT:    br label [[IF_END:%.*]]
-; CHECK:       if.end:
-; CHECK-NEXT:    ret void
-;
-; CHECK-DISABLED-LABEL: define {{[^@]+}}@foo() {
-; CHECK-DISABLED-NEXT:  entry:
-; CHECK-DISABLED-NEXT:    [[TID:%.*]] = call i32 @__kmpc_get_hardware_thread_id()
-; CHECK-DISABLED-NEXT:    [[ISMAIN:%.*]] = call signext i8 @__kmpc_is_generic_main_thread_id(i32 [[TID]])
-; CHECK-DISABLED-NEXT:    [[PRED:%.*]] = icmp eq i8 [[ISMAIN]], 1
-; CHECK-DISABLED-NEXT:    br i1 [[PRED]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
-; CHECK-DISABLED:       if.then:
-; CHECK-DISABLED-NEXT:    call void @baz()
-; CHECK-DISABLED-NEXT:    br label [[IF_END]]
-; CHECK-DISABLED:       if.end:
-; CHECK-DISABLED-NEXT:    ret void
-;
-entry:
-  %tid = call i32 @__kmpc_get_hardware_thread_id();
-  %ismain = call signext i8 @__kmpc_is_generic_main_thread_id(i32 %tid)
-  %pred = icmp eq i8 %ismain, 1
-  br i1 %pred, label %if.then, label %if.end
-
-if.then:
-  call void @baz()
-  br label %if.end
-
-if.end:
-  ret void
-}
-
-; Function Attrs: noinline
-define internal void @bar() {
-; CHECK-LABEL: define {{[^@]+}}@bar() {
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TID:%.*]] = call i32 @__kmpc_get_hardware_thread_id()
-; CHECK-NEXT:    [[ISMAIN:%.*]] = call signext i8 @__kmpc_is_generic_main_thread_id(i32 [[TID]])
-; CHECK-NEXT:    [[PRED:%.*]] = icmp eq i8 [[ISMAIN]], 1
-; CHECK-NEXT:    br i1 [[PRED]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
-; CHECK:       if.then:
-; CHECK-NEXT:    call void @baz()
-; CHECK-NEXT:    br label [[IF_END]]
-; CHECK:       if.end:
-; CHECK-NEXT:    ret void
-;
-; CHECK-DISABLED-LABEL: define {{[^@]+}}@bar() {
-; CHECK-DISABLED-NEXT:  entry:
-; CHECK-DISABLED-NEXT:    [[TID:%.*]] = call i32 @__kmpc_get_hardware_thread_id()
-; CHECK-DISABLED-NEXT:    [[ISMAIN:%.*]] = call signext i8 @__kmpc_is_generic_main_thread_id(i32 [[TID]])
-; CHECK-DISABLED-NEXT:    [[PRED:%.*]] = icmp eq i8 [[ISMAIN]], 1
-; CHECK-DISABLED-NEXT:    br i1 [[PRED]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
-; CHECK-DISABLED:       if.then:
-; CHECK-DISABLED-NEXT:    call void @baz()
-; CHECK-DISABLED-NEXT:    br label [[IF_END]]
-; CHECK-DISABLED:       if.end:
-; CHECK-DISABLED-NEXT:    ret void
-;
-entry:
-  %tid = call i32 @__kmpc_get_hardware_thread_id();
-  %ismain = call signext i8 @__kmpc_is_generic_main_thread_id(i32 %tid)
-  %pred = icmp eq i8 %ismain, 1
-  br i1 %pred, label %if.then, label %if.end
-
-if.then:
-  call void @baz()
-  br label %if.end
-
-if.end:
-  ret void
-}
-
-declare void @baz()
-
-declare i8 @__kmpc_is_generic_main_thread_id(i32)
-
-declare i32 @__kmpc_get_hardware_thread_id()
-
-declare i32 @__kmpc_target_init(%struct.ident_t*, i8, i1)
-
-declare void @__kmpc_target_deinit(%struct.ident_t*, i8)
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!3, !4, !5, !6}
-!nvvm.annotations = !{!7}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 13.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
-!1 = !DIFile(filename: "fold_generic_main_thread.c", directory: "/tmp/fold_generic_main_thread.c")
-!2 = !{}
-!3 = !{i32 2, !"Debug Info Version", i32 3}
-!4 = !{i32 1, !"wchar_size", i32 4}
-!5 = !{i32 7, !"openmp", i32 50}
-!6 = !{i32 7, !"openmp-device", i32 50}
-!7 = !{void ()* @kernel, !"kernel", i32 1}