Essential-of-Compilation/notes.md

Revising the architecture to better match Dybvig's P523 compiler

• to do: figure out where to introduce the Tail context. It seems to happen in Dybvig's A10, but that assignment doesn't say anything about it.

• to do: insert type checking

R1:

exp ::= x | n | (op exp*) | (let ([x exp]) exp)
R1 ::= (program exp)

flatten (uncover-locals, remove-let, remove-complex-opera*) | V C0:

arg ::= x | n
exp ::= arg | (op arg*)
stmt ::= (assign x exp)
tail ::= (return exp) | (block stmt* tail)
C0 ::= (program (x*) tail)

select-instructions | V

assign-homes | V

patch-instructions | V

print-x86 | V

---

R2:

exp ::= x | n | #t | #f | (op exp*) | (let ([x exp]) exp) | (if exp exp exp)
R2 ::= (program exp)

remove-complex-opera* (rco) | V

arg ::= x | n | #t | #f
exp ::= arg | (op arg*) | (let ([x exp]) exp) | (if exp exp exp)
R2 ::= (program exp)

create-CFG | V

arg ::= x | n | #t | #f
exp ::= arg | (op arg*)
tail ::= (jump label) | (if (rel-op exp*) label label) | (return exp)
stmt ::= (assign x exp)
CFG ::= (program ([label . (block stmt* tail)] tail)

flatten (uncover-locals, remove-let, remove-complex-opera*) | V C1:

arg ::= x | n | #t | #f
stmt ::= (assign x arg) | (assign (op arg*))
pred ::= #t | #f | (pred-op val*) | (if pred pred pred) | (begin stmt* pred)
tail ::= (return exp) | (block stmt* tail)
C1 ::= (program (x*) tail)

select-instructions | V

arg ::= x | n | #t | #f
exp ::= arg | (if exp exp exp) | (op arg*) | (begin stmt* exp)
stmt ::= instr | (if exp stmt stmt) | (begin stmt* stmt)
iarg ::= (var x) | (int n)
instr ::= (addq iarg iarg) | ...
pseudo-x86 :: (program (x*) stmt)

uncover-live, build-interference, allocate-registers | V

arg ::= x | n | #t | #f
exp ::= arg | (if exp exp exp) | (op arg*) | (begin stmt* exp)
stmt ::= instr | (if exp stmt stmt) | (begin stmt* stmt)
iarg ::= (reg r) | (deref r n) | (int n)
instr ::= (addq iarg iarg) | ...
pseudo-x86 :: (program (x*) stmt)

expose-basic-blocks (create-cfg) | V

inst ::= ...
stmt ::= (jump label) | (if (pre-op arg*) label label) | (begin instr* stmt)
cfg-x86 ::= (program ([label . stmt]*) stmt)

optimize-jumps | V

stmt ::= (jump label) | (if (pre-op arg*) label label) | (begin instr* stmt)
cfg-x86 ::= (program ([label . stmt]*) stmt)

print-x86 | V