[coroutine] should disable inline before calling coro split

This is a rework of D85812, which didn't land.
When callee coroutine function is inlined into caller coroutine function before coro-split pass, llvm will emits "coroutine should have exactly one defining @llvm.coro.begin". It seems that coro-early pass can not handle this quiet well.
So we believe that unsplited coroutine function should not be inlined.
This patch fix such issue by not inlining function if it has attribute "coroutine.presplit" (it means the function has not been splited) to fix this issue
test plan: check-llvm, check-clang

In D85812, there was suggestions on moving the macros to Attributes.td to avoid circular header dependency issue.
I believe it's not worth doing just to be able to use one constant string in one place.
Today, there are already 3 possible attribute values for "coroutine.presplit": c6543cc6b8/llvm/lib/Transforms/Coroutines/CoroInternal.h (L40-L42)
If we move them into Attributes.td, we would be adding 3 new attributes to EnumAttr, just to support this, which I think is an overkill.

Instead, I think the best way to do this is to add an API in Function class that checks whether this function is a coroutine, by checking the attribute by name directly.

Differential Revision: https://reviews.llvm.org/D92706

include/llvm/IR/Function.h

@@ -268,6 +268,12 @@ public:
         getContext(), AttributeList::FunctionIndex, Kind));
   }
 
+  /// A function will have the "coroutine.presplit" attribute if it's
+  /// a coroutine and has not gone through full CoroSplit pass.
+  bool isPresplitCoroutine() const {
+    return hasFnAttribute("coroutine.presplit");
+  }
+
   enum ProfileCountType { PCT_Invalid, PCT_Real, PCT_Synthetic };
 
   /// Class to represent profile counts.

lib/Analysis/InlineCost.cpp

@@ -2332,6 +2332,13 @@ Optional<InlineResult> llvm::getAttributeBasedInliningDecision(
   if (!Callee)
     return InlineResult::failure("indirect call");
 
+  // When callee coroutine function is inlined into caller coroutine function
+  // before coro-split pass,
+  // coro-early pass can not handle this quiet well.
+  // So we won't inline the coroutine function if it have not been unsplited
+  if (Callee->isPresplitCoroutine())
+    return InlineResult::failure("unsplited coroutine call");
+
   // Never inline calls with byval arguments that does not have the alloca
   // address space. Since byval arguments can be replaced with a copy to an
   // alloca, the inlined code would need to be adjusted to handle that the

lib/Transforms/IPO/AlwaysInliner.cpp

@@ -46,7 +46,14 @@ PreservedAnalyses AlwaysInlinerPass::run(Module &M,
   SmallSetVector<CallBase *, 16> Calls;
   bool Changed = false;
   SmallVector<Function *, 16> InlinedFunctions;
-  for (Function &F : M)
+  for (Function &F : M) {
+    // When callee coroutine function is inlined into caller coroutine function
+    // before coro-split pass,
+    // coro-early pass can not handle this quiet well.
+    // So we won't inline the coroutine function if it have not been unsplited
+    if (F.isPresplitCoroutine())
+      continue;
+
     if (!F.isDeclaration() && F.hasFnAttribute(Attribute::AlwaysInline) &&
         isInlineViable(F).isSuccess()) {
       Calls.clear();
@@ -90,6 +97,7 @@ PreservedAnalyses AlwaysInlinerPass::run(Module &M,
       // invalidation issues while deleting functions.
       InlinedFunctions.push_back(&F);
     }
+  }
 
   // Remove any live functions.
   erase_if(InlinedFunctions, [&](Function *F) {
@@ -182,6 +190,13 @@ InlineCost AlwaysInlinerLegacyPass::getInlineCost(CallBase &CB) {
   if (!Callee)
     return InlineCost::getNever("indirect call");
 
+  // When callee coroutine function is inlined into caller coroutine function
+  // before coro-split pass,
+  // coro-early pass can not handle this quiet well.
+  // So we won't inline the coroutine function if it have not been unsplited
+  if (Callee->isPresplitCoroutine())
+    return InlineCost::getNever("unsplited coroutine call");
+
   // FIXME: We shouldn't even get here for declarations.
   if (Callee->isDeclaration())
     return InlineCost::getNever("no definition");

test/Transforms/Coroutines/Inputs/sample.text.prof

@@ -0,0 +1,5 @@
+ff:152730084:141806
+  1: 123
+
+foo:152730084:141806
+  65492: ff:302659

test/Transforms/Coroutines/coro-inline.ll

@@ -0,0 +1,43 @@
+; RUN: opt < %s -always-inline -barrier -coro-early -barrier -coro-split -S | FileCheck %s
+; RUN: opt < %s -enable-new-pm  -always-inline -coro-early -coro-split  -S | FileCheck %s
+; RUN: opt < %s -sample-profile-file=%S/Inputs/sample.text.prof -pgo-kind=pgo-sample-use-pipeline -coro-early -barrier -sample-profile -barrier -coro-split  -disable-inlining=true -S | FileCheck %s
+; RUN: opt < %s -enable-new-pm -sample-profile-file=%S/Inputs/sample.text.prof -pgo-kind=pgo-sample-use-pipeline -coro-early -sample-profile -coro-split  -disable-inlining=true -S | FileCheck %s
+
+; Function Attrs: alwaysinline ssp uwtable
+define void @ff() #0 !dbg !12 {
+entry:
+  %id = call token @llvm.coro.id(i32 16, i8* null, i8* null, i8* null)
+  %begin = call i8* @llvm.coro.begin(token %id, i8* null)
+  ret void
+}
+
+; CHECK:  call void @ff()
+; Function Attrs: alwaysinline ssp uwtable
+define void @foo() #0 !dbg !8 {
+entry:
+  %id1 = call token @llvm.coro.id(i32 16, i8* null, i8* null, i8* null)
+  %begin = call i8* @llvm.coro.begin(token %id1, i8* null)
+  call void @ff(), !dbg !11
+  ret void
+}
+
+declare token @llvm.coro.id(i32, i8* readnone, i8* nocapture readonly, i8*)
+declare i8* @llvm.coro.begin(token, i8* writeonly)
+
+attributes #0 = { alwaysinline ssp uwtable "coroutine.presplit"="1" "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-sample-profile" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "inline_O2.cpp", directory: "")
+!2 = !{}
+!3 = !{i32 7, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{i32 7, !"PIC Level", i32 2}
+!8 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: !1, file: !1, line: 46, type: !9, scopeLine: 46, flags: DIFlagPrototyped, unit: !0, retainedNodes: !2)
+!9 = !DISubroutineType(types: !10)
+!10 = !{null}
+!11 = !DILocation(line: 2, column: 0, scope: !8)
+!12 = distinct !DISubprogram(name: "ff", linkageName: "ff", scope: !1, file: !1, line: 46, type: !9, scopeLine: 46, flags: DIFlagPrototyped, unit: !0, retainedNodes: !2)