[llvm] [SPIRV] Add 64 bit lowering for bitreverse (PR #193068)

[Dmitry Sidorov via llvm-commits]

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@@ -3576,6 +3579,53 @@ bool SPIRVInstructionSelector::handle64BitOverflow(
                           SPIRV::OpCompositeConstruct);
 }
 
+bool SPIRVInstructionSelector::selectBitreverse64(Register ResVReg,
+                                                  SPIRVTypeInst ResType,
+                                                  MachineInstr &I,
+                                                  Register SrcReg) const {
+  unsigned ComponentCount = GR.getScalarOrVectorComponentCount(ResType);
+  if (ComponentCount > 2)
+    return handle64BitOverflow(
+        ResVReg, ResType, I, SrcReg, SPIRV::OpBitReverse,
+        [this](Register R, SPIRVTypeInst T, MachineInstr &I, Register S,
+               unsigned O) { return this->selectBitreverse64(R, T, I, S); });
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MrSidims wrote:

`O` is passed, but unused. Does it trigger a compiler warning?

https://github.com/llvm/llvm-project/pull/193068