CODEGEN_NOTES.md

S2S (Scheme to scheme) calling convention

Stack after call instr

[...] retAddr <- %rsp r10 = frameDescr rdi = thisClosure rsi = arg0 rdx = arg1 rcx = arg2

prologue

push r10 push rdi push rsi push rdx push rcx

(define a val)

[code for val]

(func a1 a2 a3)

[code for func] pop %rdi [code for a1] pop %rsi [code for a2] pop %rdx [code for a3] pop %rcx mov frameDescr, %r10 [test and extract codeptr to %rax] call %rax push %rax

return x (frameSize = args + locals + thisClosure + frameDescr)

[code for x] pop %rax add $8 * frameSize, %rsp ret

tailcall (func a1 a2 a3)

[code for func] pop %rdi [code for a1] pop %rsi [code for a2] pop %rdx [code for a3] pop %rcx add $8, frameSize [test and extract codeptr to %rax] jmp %rax

Runtime GC call

mov allocSize, %rdi mov %rsp, %rsi mov frameDescr, %rdx mov threadState, %rcx call collectAndAlloc