Code generation

The module ppci.codegen provides functions and classes to generate code.

Back-end

The back-end is more complicated. There are several steps to be taken here.

  1. Tree creation
  2. Instruction selection
  3. Register allocation
  4. Peep hole optimization
digraph codegen {
1 [label="IR-code"]

10 [label="irdag"]
20 [label="dagsplitter"]
30 [label="instruction selector"]
40 [label="register allocator"]

49 [label="assembly parser"]
50 [label="outstream"]
60 [label="object file"]
61 [label="text output"]
1 -> 10
10 -> 20 [label="Selection DAG"]
20 -> 30 [label="Selection Trees"]
30 -> 40 [label="frame"]
40 -> 50 [label="frame"]

49 -> 50
50 -> 60
50 -> 61
}

Canonicalize

During this phase, the IR-code is made simpler. Also unsupported operations are rewritten into function calls. For example soft floating point is introduced here.