DAG is an intermediate code representation which is generated by ICG module of compiler which comes under the front end/Machine independent phase of compiler.
Yes the output of compiler to be more specific output of target code generator is machine dependent and is called assembly language.
The assembler takes assembly language and converts it into relocatable machine code not the compiler.
Machine independent modules:
lexical,syntax,semantic analyser; ICG
Machine dependent modules:
Code optimiser,target code generator .
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