[llvm] [RISCV][GISel] Add ISel supports for SHXADD from Zba extension (PR #67863)

[Craig Topper via llvm-commits]

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@@ -235,10 +235,7 @@ def SimmShiftRightBy3XForm : SDNodeXForm<imm, [{
 }]>;
 
 // Pattern to exclude simm12 immediates from matching.
-def non_imm12 : PatLeaf<(XLenVT GPR:$a), [{
-  auto *C = dyn_cast<ConstantSDNode>(N);
-  return !C || !isInt<12>(C->getSExtValue());
-}]>;
+def non_imm12 : ComplexPattern<XLenVT, 1, "selectNonImm12", [], [], 0>;
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topperc wrote:

Can you add `let GISelPredicateCode` here to do this without changing to a complex pattern?

https://github.com/llvm/llvm-project/pull/67863