[clang] 73a1b16 - Add docs for function attributes hot/cold

[Aaron Ballman via cfe-commits]

Author: Ofek Shilon
Date: 2022-08-10T13:48:43-04:00
New Revision: 73a1b162a4cd5850a474b7cf8497aef3006094e2

URL: https://github.com/llvm/llvm-project/commit/73a1b162a4cd5850a474b7cf8497aef3006094e2
DIFF: https://github.com/llvm/llvm-project/commit/73a1b162a4cd5850a474b7cf8497aef3006094e2.diff

LOG: Add docs for function attributes hot/cold

Following https://reviews.llvm.org/D92493, this add docs for the hot
and cold function attributes.

Differential Revision: https://reviews.llvm.org/D130933

Added: 
    

Modified: 
    clang/include/clang/Basic/Attr.td
    clang/include/clang/Basic/AttrDocs.td

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 7a660c9005050..670af57c3def5 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1073,7 +1073,7 @@ def CmseNSCall : TypeAttr, TargetSpecificAttr<TargetARM> {
 def Cold : InheritableAttr {
   let Spellings = [GCC<"cold">];
   let Subjects = SubjectList<[Function]>;
-  let Documentation = [Undocumented];
+  let Documentation = [ColdFunctionEntryDocs];
   let SimpleHandler = 1;
 }
 
@@ -1519,7 +1519,7 @@ def GNUInline : InheritableAttr {
 def Hot : InheritableAttr {
   let Spellings = [GCC<"hot">];
   let Subjects = SubjectList<[Function]>;
-  let Documentation = [Undocumented];
+  let Documentation = [HotFunctionEntryDocs];
   let SimpleHandler = 1;
 }
 def : MutualExclusions<[Hot, Cold]>;

diff  --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index 0f428a5647dfc..6afd3063524c9 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -5241,6 +5241,21 @@ aarch64/aarch64-be/riscv32/riscv64/i386/x86-64 targets.
 }];
 }
 
+def HotFunctionEntryDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+``__attribute__((hot))`` marks a function as hot, as a manual alternative to PGO hotness data.
+If PGO data is available, the annotation ``__attribute__((hot))`` overrides the profile count based hotness (unlike ``__attribute__((cold))``).
+}];
+}
+
+def ColdFunctionEntryDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+``__attribute__((cold))`` marks a function as cold, as a manual alternative to PGO hotness data.
+If PGO data is available, the profile count based hotness overrides the ``__attribute__((cold))`` annotation (unlike ``__attribute__((hot))``).
+}];
+}
 def TransparentUnionDocs : Documentation {
   let Category = DocCatDecl;
   let Content = [{