Add an 'inline hint' attribute to represent source

code hints that it would be a good idea to inline
a function ("inline" keyword).  No functional change
yet; FEs do not emit this and inliner does not use it.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80063 91177308-0d34-0410-b5e6-96231b3b80d8

docs/LangRef.html

@@ -1042,6 +1042,11 @@ define void @f() optsize
       function into callers whenever possible, ignoring any active inlining size
       threshold for this caller.</dd>
 
+  <dt><tt>inlinehint</tt></dt>
+  <dd>This attribute indicates that the source code contained a hint that inlining
+      this function is desirable (such as the "inline" keyword in C/C++).  It
+      is just a hint; it imposes no requirements on the inliner.</dd>
+
   <dt><tt>noinline</tt></dt>
   <dd>This attribute indicates that the inliner should never inline this
       function in any situation. This attribute may not be used together with

include/llvm-c/Core.h

@@ -109,7 +109,8 @@ typedef enum {
     LLVMNoCaptureAttribute  = 1<<21,
     LLVMNoRedZoneAttribute  = 1<<22,
     LLVMNoImplicitFloatAttribute = 1<<23,
-    LLVMNakedAttribute      = 1<<24
+    LLVMNakedAttribute      = 1<<24,
+    LLVMInlineHintAttribute = 1<<25
 } LLVMAttribute;
 
 typedef enum {

include/llvm/Attributes.h

@@ -57,7 +57,8 @@ const Attributes NoCapture = 1<<21; ///< Function creates no aliases of pointer
 const Attributes NoRedZone = 1<<22; /// disable redzone
 const Attributes NoImplicitFloat = 1<<23; /// disable implicit floating point
                                           /// instructions.
-const Attributes Naked     = 1<<24; ///< Naked function
+const Attributes Naked           = 1<<24; ///< Naked function
+const Attributes InlineHint      = 1<<25; ///< source said inlining was desirable
 
 /// @brief Attributes that only apply to function parameters.
 const Attributes ParameterOnly = ByVal | Nest | StructRet | NoCapture;
@@ -66,7 +67,7 @@ const Attributes ParameterOnly = ByVal | Nest | StructRet | NoCapture;
 /// be used on return values or function parameters.
 const Attributes FunctionOnly = NoReturn | NoUnwind | ReadNone | ReadOnly | 
   NoInline | AlwaysInline | OptimizeForSize | StackProtect | StackProtectReq |
-  NoRedZone | NoImplicitFloat | Naked;
+  NoRedZone | NoImplicitFloat | Naked | InlineHint;
 
 /// @brief Parameter attributes that do not apply to vararg call arguments.
 const Attributes VarArgsIncompatible = StructRet;

lib/AsmParser/LLLexer.cpp

@@ -556,6 +556,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(readnone);
   KEYWORD(readonly);
 
+  KEYWORD(inlinehint);
   KEYWORD(noinline);
   KEYWORD(alwaysinline);
   KEYWORD(optsize);

lib/AsmParser/LLParser.cpp

@@ -907,6 +907,7 @@ bool LLParser::ParseOptionalAttrs(unsigned &Attrs, unsigned AttrKind) {
     case lltok::kw_noinline:        Attrs |= Attribute::NoInline; break;
     case lltok::kw_readnone:        Attrs |= Attribute::ReadNone; break;
     case lltok::kw_readonly:        Attrs |= Attribute::ReadOnly; break;
+    case lltok::kw_inlinehint:      Attrs |= Attribute::InlineHint; break;
     case lltok::kw_alwaysinline:    Attrs |= Attribute::AlwaysInline; break;
     case lltok::kw_optsize:         Attrs |= Attribute::OptimizeForSize; break;
     case lltok::kw_ssp:             Attrs |= Attribute::StackProtect; break;

lib/AsmParser/LLToken.h

@@ -82,6 +82,7 @@ namespace lltok {
     kw_readnone,
     kw_readonly,
 
+    kw_inlinehint,
     kw_noinline,
     kw_alwaysinline,
     kw_optsize,

lib/Target/CppBackend/CPPBackend.cpp

@@ -472,6 +472,7 @@ namespace {
         HANDLE_ATTR(Nest);
         HANDLE_ATTR(ReadNone);
         HANDLE_ATTR(ReadOnly);
+        HANDLE_ATTR(InlineHint);
         HANDLE_ATTR(NoInline);
         HANDLE_ATTR(AlwaysInline);
         HANDLE_ATTR(OptimizeForSize);

lib/VMCore/Attributes.cpp

@@ -55,6 +55,8 @@ std::string Attribute::getAsString(Attributes Attrs) {
     Result += "optsize ";
   if (Attrs & Attribute::NoInline)
     Result += "noinline ";
+  if (Attrs & Attribute::InlineHint)
+    Result += "inlinehint ";
   if (Attrs & Attribute::AlwaysInline)
     Result += "alwaysinline ";
   if (Attrs & Attribute::StackProtect)

utils/llvm.grm

@@ -161,6 +161,7 @@ FuncAttr      ::= noreturn
  | signext
  | readnone
  | readonly
+ | inlinehint
  | noinline
  | alwaysinline
  | optsize

utils/vim/llvm.vim

@@ -51,7 +51,7 @@ syn keyword llvmKeyword volatile fastcc coldcc cc ccc
 syn keyword llvmKeyword x86_stdcallcc x86_fastcallcc
 syn keyword llvmKeyword signext zeroext inreg sret nounwind noreturn
 syn keyword llvmKeyword nocapture byval nest readnone readonly noalias
-syn keyword llvmKeyword noinline alwaysinline optsize ssp sspreq
+syn keyword llvmKeyword inlinehint noinline alwaysinline optsize ssp sspreq
 syn keyword llvmKeyword noredzone noimplicitfloat naked
 syn keyword llvmKeyword module asm align tail to
 syn keyword llvmKeyword addrspace section alias sideeffect c gc