[llvm] [Target][RISCV] Add HwMode support to subregister index size/offset. (PR #86368)

[via llvm-commits]

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@@ -1399,28 +1406,47 @@ CodeGenSubRegIndex *CodeGenRegBank::getConcatSubRegIndex(
 
   // None exists, synthesize one.
   std::string Name = Parts.front()->getName();
-  // Determine whether all parts are contiguous.
-  bool IsContinuous = true;
-  unsigned Size = Parts.front()->Size;
-  unsigned LastOffset = Parts.front()->Offset;
-  unsigned LastSize = Parts.front()->Size;
   const unsigned UnknownSize = (uint16_t)-1;
+
   for (unsigned i = 1, e = Parts.size(); i != e; ++i) {
     Name += '_';
     Name += Parts[i]->getName();
-    if (Size == UnknownSize || Parts[i]->Size == UnknownSize)
-      Size = UnknownSize;
-    else
-      Size += Parts[i]->Size;
-    if (LastSize == UnknownSize || Parts[i]->Offset != (LastOffset + LastSize))
-      IsContinuous = false;
-    LastOffset = Parts[i]->Offset;
-    LastSize = Parts[i]->Size;
   }
+
   Idx = createSubRegIndex(Name, Parts.front()->getNamespace());
-  Idx->Size = Size;
-  Idx->Offset = IsContinuous ? Parts.front()->Offset : -1;
   Idx->ConcatenationOf.assign(Parts.begin(), Parts.end());
+
+  unsigned NumModes = CGH.getNumModeIds();
+  for (unsigned M = 0; M < NumModes; ++M) {
+    const CodeGenSubRegIndex *Part = Parts.front();
+
+    // Determine whether all parts are contiguous.
+    bool IsContinuous = true;
+    const SubRegRange &FirstPartRange = Part->Range.get(M);
+    unsigned Size = FirstPartRange.Size;
+    unsigned LastOffset = FirstPartRange.Offset;
+    unsigned LastSize = FirstPartRange.Size;
+
+    for (unsigned i = 1, e = Parts.size(); i != e; ++i) {
+      Part = Parts[i];
+      Name += '_';
+      Name += Part->getName();
+
+      const SubRegRange &PartRange = Part->Range.get(M);
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superZWT123 wrote:

 Hi, topperc :
In your previous implementation with ‘R->getValue(“SubRegRanges”)’, it appears that ‘Range’ indeed only includes the HwModes that control the ‘SubRegRanges’, right? Now, if I were to define a new HwMode but not use it to control anything, would invoking ‘Range.get(M)’ lead to an error? This is because ‘getNumModeIds()’ returns the IDs of all  HwModes, while ‘Range’ only contains those that actually control the ‘SubRegRanges’.

https://github.com/llvm/llvm-project/pull/86368