[llvm] [RISCV][GISEL] Add legalizer for G_BSWAP (PR #70226)

[Craig Topper via llvm-commits]

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@@ -81,6 +81,11 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST) {
         .clampScalar(BigTyIdx, XLenLLT, XLenLLT);
   }
 
+  getActionDefinitionsBuilder(G_BSWAP)
+    .widenScalarToNextPow2(0)
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topperc wrote:

I guess the clamp causes it to be split as a BSWAP instead of creating a bunch of i64 shifts, ands, ors that need to be independently split?

https://github.com/llvm/llvm-project/pull/70226