[llvm] [RISCV] Refactor subreg indices. (PR #77173)

[Jessica Clarke via llvm-commits]

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@@ -63,7 +63,8 @@ def sub_vrm1_5 : ComposedSubRegIndex<sub_vrm2_2, sub_vrm1_1>;
 def sub_vrm1_6 : ComposedSubRegIndex<sub_vrm2_3, sub_vrm1_0>;
 def sub_vrm1_7 : ComposedSubRegIndex<sub_vrm2_3, sub_vrm1_1>;
 
-def sub_32_hi  : SubRegIndex<32, 32>;
+def sub_gpr_even : SubRegIndex<32>;
+def sub_gpr_odd  : SubRegIndex<32>;
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jrtc27 wrote:

Why do we need a new one? This is exactly the same as sub_32, and always will be, because they mean the same thing.

https://github.com/llvm/llvm-project/pull/77173