[llvm] [GlobalIsel] Combine trunc of binop (PR #107721)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

trunc (binop X, C) --> binop (trunc X, trunc C) is actually misleading. It is actually:
trunc (binop X, C) --> binop (trunc X, C), which does not match your pattern.


https://github.com/llvm/llvm-project/pull/107721