[llvm] [RISCV] Add groupid/bitmask for RISC-V extension (PR #94440)

[Craig Topper via llvm-commits]

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@@ -24,6 +24,14 @@ class Triple;
 
 namespace RISCV {
 
+namespace RISCVExtensionBitmaskTable {
+struct RISCVExtensionBitmask {
+  const char *Name;
+  unsigned GroupID;
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topperc wrote:

Can we store just a single index value where 0-63 means its in group 0, 64-127 means it is in group 1, 128-191 means its in group 2, etc.

https://github.com/llvm/llvm-project/pull/94440