[llvm] 6afdf40 - [TableGen] Stabilize sort in GET_SUBTARGETINFO_MACRO block

[Kevin P. Neal via llvm-commits]

Author: Kevin P. Neal
Date: 2023-06-28T08:28:47-04:00
New Revision: 6afdf4052551bb3eea013c8ffeeb30112ccd69a3

URL: https://github.com/llvm/llvm-project/commit/6afdf4052551bb3eea013c8ffeeb30112ccd69a3
DIFF: https://github.com/llvm/llvm-project/commit/6afdf4052551bb3eea013c8ffeeb30112ccd69a3.diff

LOG: [TableGen] Stabilize sort in GET_SUBTARGETINFO_MACRO block

The sort of the elements in the GET_SUBTARGETINFO_MACRO block is done on
the "Name" field of each record. This field is not guaranteed to be unique,
is not guaranteed to even have a value at all, and is not used in the
output anyway. Change to sort on the "FieldName" field which should be
unique.

Problem spotted when lib/Target/PowerPC/PPCGenSubtargetInfo.inc changed
unexpectedly.

Differential Revision: https://reviews.llvm.org/D153371

Added: 
    

Modified: 
    llvm/include/llvm/TableGen/Record.h
    llvm/utils/TableGen/SubtargetEmitter.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/TableGen/Record.h b/llvm/include/llvm/TableGen/Record.h
index 321b0f4566be84..698e777748cc29 100644
--- a/llvm/include/llvm/TableGen/Record.h
+++ b/llvm/include/llvm/TableGen/Record.h
@@ -2033,6 +2033,15 @@ struct LessRecordFieldName {
   }
 };
 
+/// Sorting predicate to sort record pointers by their
+/// FieldName field.
+struct LessRecordFieldFieldName {
+  bool operator()(const Record *Rec1, const Record *Rec2) const {
+    return Rec1->getValueAsString("FieldName") <
+           Rec2->getValueAsString("FieldName");
+  }
+};
+
 struct LessRecordRegister {
   struct RecordParts {
     SmallVector<std::pair< bool, StringRef>, 4> Parts;

diff  --git a/llvm/utils/TableGen/SubtargetEmitter.cpp b/llvm/utils/TableGen/SubtargetEmitter.cpp
index 5ab0d8e911d0f6..c63c8f1f4aa931 100644
--- a/llvm/utils/TableGen/SubtargetEmitter.cpp
+++ b/llvm/utils/TableGen/SubtargetEmitter.cpp
@@ -202,7 +202,7 @@ void SubtargetEmitter::EmitSubtargetInfoMacroCalls(raw_ostream &OS) {
 
   std::vector<Record *> FeatureList =
       Records.getAllDerivedDefinitions("SubtargetFeature");
-  llvm::sort(FeatureList, LessRecordFieldName());
+  llvm::sort(FeatureList, LessRecordFieldFieldName());
 
   for (const Record *Feature : FeatureList) {
     const StringRef FieldName = Feature->getValueAsString("FieldName");