[llvm] [ISel] Introduce llvm.clmul intrinsic (PR #168731)

[Piotr Fusik via llvm-commits]

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@@ -0,0 +1,11462 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 -mattr=+m -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV32IM
+; RUN: llc -mtriple=riscv64 -mattr=+m -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV64IM
+
+define i4 @clmul_i4(i4 %a, i4 %b) nounwind {
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pfusik wrote:

This is expanded XLEN-wide clmul. Can we expand `i4` clmul instead?

https://github.com/llvm/llvm-project/pull/168731