[llvm] [RISCV][GISEL] legalize, regbankselect, and instruction-select for G_… (PR #73061)

[Matt Arsenault via llvm-commits]

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@@ -86,6 +86,10 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST) {
     unsigned BigTyIdx = Op == G_MERGE_VALUES ? 0 : 1;
     unsigned LitTyIdx = Op == G_MERGE_VALUES ? 1 : 0;
     getActionDefinitionsBuilder(Op)
+        .legalIf([=, &ST](const LegalityQuery &Query) -> bool {
+          return ST.hasStdExtD() && typeIs(LitTyIdx, s32)(Query) &&
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arsenm wrote:

I'd suggest moving the subtarget check out of the predicate callback, and conditionally adding a standard type check to the action builder 

https://github.com/llvm/llvm-project/pull/73061