[llvm] [NVPTX] Remove `NVPTX::IMAD` opcode, and rely on intruction selection only (PR #121724)

[via llvm-commits]

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@@ -4442,14 +4441,8 @@ PerformADDCombineWithOperands(SDNode *N, SDValue N0, SDValue N1,
   if (!N0.getNode()->hasOneUse())
     return SDValue();
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peterbell10 wrote:

Changed to require one use and added test.


https://github.com/llvm/llvm-project/pull/121724