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|
; CALLING CONVENTION:
; Here is the process for calling a function:
; - the caller pushes the arguments on to the stack, from right to left
; - the caller subtracts sizeof(return type) from rsp, rounded up to the nearest 8 bytes
; - the caller calls the function
; - the caller stores away the return value
; - the caller adds (sizeof(return type) + sizeof arg0 + ... + sizeof argn) to rsp - where each sizeof is rounded up to the nearest 8 bytes
; STACK LAYOUT:
; arg n
; ...
; arg 0
; return value [rbp+16]
; return address [rbp+8]
; old rbp [rbp]
; local variables
global code_output
global codegen_second_pass ; = 0 on first global pass, 1 on second global pass
global functions_addresses ; ident list of addresses
global functions_labels ; ident list of ident lists of label addresses
global curr_function_labels ; ident list of labels for current function (written to in 1st pass, read from in 2nd pass)
global curr_function_return_type
#define REG_RAX 0
#define REG_RBX 3
#define REG_RCX 1
#define REG_RDX 2
#define REG_RSP 4
#define REG_RBP 5
#define REG_RSI 6
#define REG_RDI 7
function emit_byte
argument byte
*1code_output = byte
code_output += 1
return
function emit_bytes
argument bytes
argument count
memcpy(code_output, bytes, count)
code_output += count
return
function emit_word
argument word
*2code_output = word
code_output += 2
return
function emit_dword
argument word
*4code_output = word
code_output += 4
return
function emit_qword
argument word
*8code_output = word
code_output += 8
return
; e.g. emit_mov_reg(REG_RAX, REG_RBX) emits mov rax, rbx
function emit_mov_reg
argument dest
argument src
local n
if src ] 7 goto bad_reg
if dest ] 7 goto bad_reg
;48 89 (DEST|SRC<<3|0xc0)
*2code_output = 0x8948
code_output += 2
n = 0xc0 | dest
n |= src < 3
*1code_output = n
code_output += 1
return
:bad_reg
die(.str_bad_reg)
:str_bad_reg
string Internal compiler error: bad register passed to emit_mov_reg.
byte 0
function emit_mov_rax_imm64
argument imm64
if imm64 == 0 goto rax_imm64_0
; 48 b8 IMM64
*2code_output = 0xb848
code_output += 2
*8code_output = imm64
code_output += 8
return
:rax_imm64_0
emit_zero_rax()
return
function emit_mov_rbx_imm64
; 48 bb IMM64
argument imm64
*2code_output = 0xbb48
code_output += 2
*8code_output = imm64
code_output += 8
return
function emit_zero_rax
; 31 c0
*2code_output = 0xc031
code_output += 2
return
function emit_zero_rdx
; 31 d2
*2code_output = 0xd231
code_output += 2
return
function emit_movsx_rax_al
; 48 0f be c0
*4code_output = 0xc0be0f48
code_output += 4
return
function emit_movsx_rax_ax
; 48 0f bf c0
*4code_output = 0xc0bf0f48
code_output += 4
return
function emit_movsx_rax_eax
; 48 63 c0
*2code_output = 0x6348
code_output += 2
*1code_output = 0xc0
code_output += 1
return
function emit_movzx_rax_al
; 48 0f b6 c0
*4code_output = 0xc0b60f48
code_output += 4
return
function emit_movzx_rax_ax
; 48 0f b7 c0
*4code_output = 0xc0b70f48
code_output += 4
return
function emit_mov_eax_eax
; 89 c0
*2code_output = 0xc089
code_output += 2
return
function emit_mov_al_byte_rbx
; 8a 03
*2code_output = 0x038a
code_output += 2
return
function emit_mov_byte_rbx_al
; 88 03
*2code_output = 0x0388
code_output += 2
return
function emit_mov_ax_word_rbx
; 66 8b 03
*2code_output = 0x8b66
code_output += 2
*1code_output = 0x03
code_output += 1
return
function emit_mov_word_rbx_ax
; 66 89 03
*2code_output = 0x8966
code_output += 2
*1code_output = 0x03
code_output += 1
return
function emit_mov_eax_dword_rbx
; 8b 03
*2code_output = 0x038b
code_output += 2
return
function emit_mov_dword_rbx_eax
; 89 03
*2code_output = 0x0389
code_output += 2
return
function emit_mov_rax_qword_rbx
; 48 8b 03
*2code_output = 0x8b48
code_output += 2
*1code_output = 0x03
code_output += 1
return
function emit_mov_qword_rbx_rax
; 48 89 03
*2code_output = 0x8948
code_output += 2
*1code_output = 0x03
code_output += 1
return
function emit_mov_qword_rsp_plus_imm32_rax
argument imm32
; 48 89 84 24 IMM32
*4code_output = 0x24848948
code_output += 4
*4code_output = imm32
code_output += 4
return
function emit_mov_rax_qword_rsp_plus_imm32
argument imm32
; 48 8b 84 24 IMM32
*4code_output = 0x24848b48
code_output += 4
*4code_output = imm32
code_output += 4
return
function emit_mov_rax_qword_rsp
emit_mov_rax_qword_rsp_plus_imm32(0)
return
function emit_mov_qword_rsp_rax
emit_mov_qword_rsp_plus_imm32_rax(0)
return
function emit_sub_rsp_imm32
argument imm32
;48 81 ec IMM32
*2code_output = 0x8148
code_output += 2
*1code_output = 0xec
code_output += 1
*4code_output = imm32
code_output += 4
return
function emit_mov_qword_rsp_rbp
; 48 89 2c 24
*4code_output = 0x242c8948
code_output += 4
return
function emit_mov_rbp_qword_rsp
; 48 8b 2c 24
*4code_output = 0x242c8b48
code_output += 4
return
function emit_add_rsp_imm32
argument imm32
;48 81 c4 IMM32
*2code_output = 0x8148
code_output += 2
*1code_output = 0xc4
code_output += 1
*4code_output = imm32
code_output += 4
return
function emit_ret
*1code_output = 0xc3
code_output += 1
return
function emit_call_rax
; ff d0
*2code_output = 0xd0ff
code_output += 2
return
function emit_push_rax
; 50
*1code_output = 0x50
code_output += 1
return
function emit_pop_rax
; 58
*1code_output = 0x58
code_output += 1
return
function emit_syscall
; 0f 05
*2code_output = 0x050f
code_output += 2
return
function emit_lea_rax_rbp_plus_imm32
; 48 8d 85 IMM32
argument imm32
*2code_output = 0x8d48
code_output += 2
*1code_output = 0x85
code_output += 1
*4code_output = imm32
code_output += 4
return
function emit_lea_rsp_rbp_plus_imm32
; 48 8d a5 IMM32
argument imm32
*2code_output = 0x8d48
code_output += 2
*1code_output = 0xa5
code_output += 1
*4code_output = imm32
code_output += 4
return
function emit_mov_rax_qword_rbp_plus_imm32
; 48 8b 85 IMM32
argument imm32
*2code_output = 0x8b48
code_output += 2
*1code_output = 0x85
code_output += 1
*4code_output = imm32
code_output += 4
return
function emit_rep_movsb
; f3 a4
*2code_output = 0xa4f3
code_output += 2
return
function emit_movsq
; 48 a5
*2code_output = 0xa548
code_output += 2
return
function emit_movq_rax_xmm0
; 66 48 0f 7e c0
*4code_output = 0x7e0f4866
code_output += 4
*1code_output = 0xc0
code_output += 1
return
function emit_movq_xmm0_rax
; 66 48 0f 6e c0
*4code_output = 0x6e0f4866
code_output += 4
*1code_output = 0xc0
code_output += 1
return
function emit_movq_xmm1_rax
; 66 48 0f 6e c8
*4code_output = 0x6e0f4866
code_output += 4
*1code_output = 0xc8
code_output += 1
return
function emit_movq_xmm1_xmm0
; f3 0f 7e c8
*4code_output = 0xc87e0ff3
code_output += 4
return
function emit_cvtss2sd_xmm0_xmm0
; f3 0f 5a c0
*4code_output = 0xc05a0ff3
code_output += 4
return
function emit_cvtsd2ss_xmm0_xmm0
; f2 0f 5a c0
*4code_output = 0xc05a0ff2
code_output += 4
return
function emit_cvttsd2si_rax_xmm0
; f2 48 0f 2c c0
*4code_output = 0x2c0f48f2
code_output += 4
*1code_output = 0xc0
code_output += 1
return
function emit_cvtsi2sd_xmm0_rax
; f2 48 0f 2a c0
*4code_output = 0x2a0f48f2
code_output += 4
*1code_output = 0xc0
code_output += 1
return
function emit_addsd_xmm0_xmm1
*4code_output = 0xc1580ff2
code_output += 4
return
function emit_subsd_xmm0_xmm1
*4code_output = 0xc15c0ff2
code_output += 4
return
function emit_mulsd_xmm0_xmm1
*4code_output = 0xc1590ff2
code_output += 4
return
function emit_divsd_xmm0_xmm1
*4code_output = 0xc15e0ff2
code_output += 4
return
function emit_neg_rax
; 48 f7 d8
*2code_output = 0xf748
code_output += 2
*1code_output = 0xd8
code_output += 1
return
function emit_not_rax
; 48 f7 d0
*2code_output = 0xf748
code_output += 2
*1code_output = 0xd0
code_output += 1
return
function emit_add_rax_rbx
; 48 01 d8
*2code_output = 0x0148
code_output += 2
*1code_output = 0xd8
code_output += 1
return
function emit_sub_rax_rbx
; 48 29 d8
*2code_output = 0x2948
code_output += 2
*1code_output = 0xd8
code_output += 1
return
function emit_imul_rbx
; 48 f7 eb
*2code_output = 0xf748
code_output += 2
*1code_output = 0xeb
code_output += 1
return
function emit_idiv_rbx
; 48 f7 fb
*2code_output = 0xf748
code_output += 2
*1code_output = 0xfb
code_output += 1
return
function emit_mul_rbx
; 48 f7 e3
*2code_output = 0xf748
code_output += 2
*1code_output = 0xe3
code_output += 1
return
function emit_div_rbx
; 48 f7 f3
*2code_output = 0xf748
code_output += 2
*1code_output = 0xf3
code_output += 1
return
function emit_and_rax_rbx
; 48 21 d8
*2code_output = 0x2148
code_output += 2
*1code_output = 0xd8
code_output += 1
return
function emit_or_rax_rbx
; 48 09 d8
*2code_output = 0x0948
code_output += 2
*1code_output = 0xd8
code_output += 1
return
function emit_xor_rax_rbx
; 48 31 d8
*2code_output = 0x3148
code_output += 2
*1code_output = 0xd8
code_output += 1
return
function emit_shl_rax_cl
; 48 d3 e0
*2code_output = 0xd348
code_output += 2
*1code_output = 0xe0
code_output += 1
return
function emit_shr_rax_cl
; 48 d3 e8
*2code_output = 0xd348
code_output += 2
*1code_output = 0xe8
code_output += 1
return
function emit_sar_rax_cl
; 48 d3 f8
*2code_output = 0xd348
code_output += 2
*1code_output = 0xf8
code_output += 1
return
function emit_cqo
; 48 99
*2code_output = 0x9948
code_output += 2
return
function emit_test_rax_rax
; 48 85 c0
*2code_output = 0x8548
code_output += 2
*1code_output = 0xc0
code_output += 1
return
function emit_jmp_rel32
; e9 REL32
argument rel32
*1code_output = 0xe9
code_output += 1
*4code_output = rel32
code_output += 4
return
function emit_je_rel32
; 0f 84 REL32
argument rel32
*2code_output = 0x840f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_jne_rel32
; 0f 85 REL32
argument rel32
*2code_output = 0x850f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_jl_rel32
; 0f 8c REL32
argument rel32
*2code_output = 0x8c0f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_jg_rel32
; 0f 8f REL32
argument rel32
*2code_output = 0x8f0f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_jle_rel32
; 0f 8e REL32
argument rel32
*2code_output = 0x8e0f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_jge_rel32
; 0f 8d REL32
argument rel32
*2code_output = 0x8d0f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_jb_rel32
; 0f 82 REL32
argument rel32
*2code_output = 0x820f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_ja_rel32
; 0f 87 REL32
argument rel32
*2code_output = 0x870f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_jbe_rel32
; 0f 86 REL32
argument rel32
*2code_output = 0x860f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_jae_rel32
; 0f 83 REL32
argument rel32
*2code_output = 0x830f
code_output += 2
*4code_output = rel32
code_output += 4
return
function emit_comisd_xmm0_xmm1
; 66 0f 2f c1
*4code_output = 0xc12f0f66
code_output += 4
return
; make sure you put the return value in the proper place before calling this
function generate_return
emit_mov_reg(REG_RSP, REG_RBP)
emit_mov_rbp_qword_rsp()
emit_add_rsp_imm32(8)
emit_ret()
return
; copy sizeof(type) bytes, rounded up to the nearest 8, from rsi to rdi
function generate_copy_rsi_to_rdi_qwords
argument type
local n
n = type_sizeof(type)
n = round_up_to_8(n)
if n == 8 goto rsi2rdi_qwords_simple
; this is a struct or something, use rep movsb
emit_mov_rax_imm64(n)
emit_mov_reg(REG_RCX, REG_RAX)
emit_rep_movsb()
return
:rsi2rdi_qwords_simple
; copy 8 bytes from rsi to rdi
; this is a little "optimization" over rep movsb with rcx = 8, mainly it just makes debugging easier (otherwise you'd need 8 `stepi`s in gdb to skip over the instruction)
emit_movsq()
return
; cast whatever was just pushed onto the stack from from_type to to_type
; `statement` is used for errors
function generate_cast_top_of_stack
argument statement
argument from_type
argument to_type
local from
local to
local c
local d
from = types + from_type
to = types + to_type
if *1to == TYPE_VOID goto gen_cast_to_void
if *1from == TYPE_VOID goto bad_gen_cast ; cast from void to something - that's bad
if *1from == TYPE_ARRAY goto bad_gen_cast ; cast array (this probably won't ever happen because of decaying)
if *1to == TYPE_ARRAY goto bad_gen_cast ; cast to array
if *1from == TYPE_FUNCTION goto bad_gen_cast ; shouldn't happen
if *1to == TYPE_FUNCTION goto bad_gen_cast ; shouldn't happen
if *1to == TYPE_STRUCT goto gen_cast_to_struct
if *1from == TYPE_STRUCT goto bad_gen_cast ; cast from struct to something else
if *1to < TYPE_FLOAT goto gen_cast_to_integer
if *1to == TYPE_POINTER goto gen_cast_to_integer ; pointers are basically integers
; cast to float/double
if *1from == TYPE_POINTER goto bad_gen_cast ; pointer to float/double
if *1to == *1from goto return_0
if *1from == TYPE_DOUBLE goto gen_cast_double_to_float
if *1from == TYPE_FLOAT goto gen_cast_float_to_double
; int to float/double
if *1to == TYPE_FLOAT goto gen_cast_int_to_float
if *1to == TYPE_DOUBLE goto gen_cast_int_to_double
goto bad_gen_cast ; in theory we shouldn't get here
:gen_cast_to_void
; we need to handle rsp properly for stuff like:
; SomeLargeStruct s;
; (void)s;
c = type_sizeof(from_type)
c = round_up_to_8(c)
c -= 8
if c == 0 goto return_0 ; int to void cast or something; we don't care
emit_add_rsp_imm32(c)
return
:gen_cast_to_integer
if *1from == *1to goto return_0 ; casting from type to same type
if *1from == TYPE_POINTER goto return_0 ; no need to do anything
; cast float/double to integer
if *1from == TYPE_FLOAT goto gen_cast_float_to_int
if *1from == TYPE_DOUBLE goto gen_cast_double_to_int
c = type_sizeof(*1from)
d = type_sizeof(*1to)
if d > c goto return_0 ; casting to bigger type, so we're good
if d == 8 goto return_0 ; casting from unsigned/signed long to unsigned/signed long/pointer, we're good
; mov rax, [rsp]
emit_mov_rax_qword_rsp()
; now sign/zero extend the lower part of rax to the whole of rax
if *1to == TYPE_CHAR goto gen_cast_integer_to_signed_char
if *1to == TYPE_UNSIGNED_CHAR goto gen_cast_integer_to_unsigned_char
if *1to == TYPE_SHORT goto gen_cast_integer_to_signed_short
if *1to == TYPE_UNSIGNED_SHORT goto gen_cast_integer_to_unsigned_short
if *1to == TYPE_INT goto gen_cast_integer_to_signed_int
if *1to == TYPE_UNSIGNED_INT goto gen_cast_integer_to_unsigned_int
goto bad_gen_cast ; in theory we shouldn't get here
:int2int_cast_cont
; mov [rsp], rax
emit_mov_qword_rsp_rax()
return
:gen_cast_integer_to_signed_char
emit_movsx_rax_al()
goto int2int_cast_cont
:gen_cast_integer_to_unsigned_char
emit_movzx_rax_al()
goto int2int_cast_cont
:gen_cast_integer_to_signed_short
emit_movsx_rax_ax()
goto int2int_cast_cont
:gen_cast_integer_to_unsigned_short
emit_movzx_rax_ax()
goto int2int_cast_cont
:gen_cast_integer_to_signed_int
emit_movsx_rax_eax()
goto int2int_cast_cont
:gen_cast_integer_to_unsigned_int
emit_mov_eax_eax()
goto int2int_cast_cont
:gen_cast_to_struct
; this is necessary because we add an implicit cast for return values
; so if we didn't have this, we wouldn't be able to return structs.
if *1from != TYPE_STRUCT goto bad_gen_cast
from += 1
to += 1
if *8from != *8to goto bad_gen_cast
return ; no casting needed; these are the same type
:gen_cast_double_to_float
; mov rax, [rsp]
emit_mov_rax_qword_rsp()
; movq xmm0, rax
emit_movq_xmm0_rax()
; cvtsd2ss xmm0, xmm0
emit_cvtsd2ss_xmm0_xmm0()
; movq rax, xmm0
emit_movq_rax_xmm0()
; mov [rsp], rax
emit_mov_qword_rsp_rax()
return
:gen_cast_float_to_double
; mov rax, [rsp]
emit_mov_rax_qword_rsp()
; movq xmm0, rax
emit_movq_xmm0_rax()
; cvtss2sd xmm0, xmm0
emit_cvtss2sd_xmm0_xmm0()
; movq rax, xmm0
emit_movq_rax_xmm0()
; mov [rsp], rax
emit_mov_qword_rsp_rax()
return
:gen_cast_int_to_float
; to reduce # of instructions, we first convert int to double, then double to float
; mov rax, [rsp]
emit_mov_rax_qword_rsp()
; cvtsi2sd xmm0, rax
emit_cvtsi2sd_xmm0_rax()
; cvtsd2ss xmm0, xmm0
emit_cvtsd2ss_xmm0_xmm0()
; movq rax, xmm0
emit_movq_rax_xmm0()
; mov [rsp], rax
emit_mov_qword_rsp_rax()
; it shouldn't matter that there's junk at [rsp+4]
return
:gen_cast_int_to_double
; mov rax, [rsp]
emit_mov_rax_qword_rsp()
; cvtsi2sd xmm0, rax
emit_cvtsi2sd_xmm0_rax()
; movq rax, xmm0
emit_movq_rax_xmm0()
; mov [rsp], rax
emit_mov_qword_rsp_rax()
return
:gen_cast_float_to_int
; mov rax, [rsp]
emit_mov_rax_qword_rsp()
; movq xmm0, rax
emit_movq_xmm0_rax()
; convert float to double, then double to int
; cvtss2sd xmm0, xmm0
emit_cvtss2sd_xmm0_xmm0()
; cvttsd2si rax, xmm0
emit_cvttsd2si_rax_xmm0()
; mov [rsp], rax
emit_mov_qword_rsp_rax()
return
:gen_cast_double_to_int
; mov rax, [rsp]
emit_mov_rax_qword_rsp()
; movq xmm0, rax
emit_movq_xmm0_rax()
; cvttsd2si rax, xmm0
emit_cvttsd2si_rax_xmm0()
; mov [rsp], rax
emit_mov_qword_rsp_rax()
return
:bad_gen_cast
print_statement_location(statement)
puts(.str_bad_gen_cast1)
print_type(from_type)
puts(.str_bad_gen_cast2)
print_type(to_type)
putc(10)
exit(1)
:str_bad_gen_cast1
string : Error: Cannot convert type
byte 32
byte 0
:str_bad_gen_cast2
string to type
byte 32
byte 0
; push expr, casted to to_type, onto the stack
; returns pointer to end of expr
function generate_push_expression_casted
argument statement
argument expr
argument to_type
local from_type
from_type = expr + 4
from_type = *4from_type
expr = generate_push_expression(statement, expr)
generate_cast_top_of_stack(statement, from_type, to_type)
return expr
; if type is a pointer type, returns the size of the underlying type
; otherwise, returns 1
; this is so that (int *)p + 5 adds 20 to p, instead of 5
function scale_rax_for_addition_with
argument type
local p
p = types + type
if *1p != TYPE_POINTER goto return_0
local n
p = type + 1
n = type_sizeof(p)
; now scale rax by n
emit_mov_rbx_imm64(n)
emit_mul_rbx()
return
; pop the top two things off of the stack, and push their sum
; the things should both have type `out_type` on the stack, but their original types are given by type1,2
function generate_stack_add
argument statement ; for errors (currently unused)
argument type1 ; type of 1st operand
argument type2 ; type of 2nd operand
argument out_type
local p
p = types + out_type
if *1p == TYPE_FLOAT goto generate_add_floats
if *1p == TYPE_DOUBLE goto generate_add_doubles
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
scale_rax_for_addition_with(type1) ; in case this is a pointer addition
emit_mov_reg(REG_RSI, REG_RAX) ; mov rsi, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
scale_rax_for_addition_with(type2) ; in case this is a pointer addition
emit_mov_reg(REG_RBX, REG_RSI) ; mov rbx, rsi
emit_add_rax_rbx() ; add rax, rbx
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, out_type)
return
:generate_add_floats
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_cvtss2sd_xmm0_xmm0() ; cvtss2sd xmm0, xmm0
emit_movq_xmm1_xmm0() ; movq xmm1, xmm0
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_cvtss2sd_xmm0_xmm0() ; cvtss2sd xmm0, xmm0
emit_addsd_xmm0_xmm1() ; addsd xmm0, xmm1
emit_cvtsd2ss_xmm0_xmm0() ; cvtsd2ss xmm0, xmm0
emit_movq_rax_xmm0() ; movq rax, xmm0
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
:generate_add_doubles
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_movq_xmm1_rax() ; movq xmm1, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_addsd_xmm0_xmm1() ; addsd xmm0, xmm1
emit_movq_rax_xmm0() ; movq rax, xmm0
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
; pop the top two things off of the stack, and push their difference
; the things should both have type `out_type` on the stack, but their original types are given by type1,2
function generate_stack_sub
argument statement ; for errors
argument type1 ; type of 1st operand
argument type2 ; type of 2nd operand
argument out_type
local p
p = types + out_type
if *1p == TYPE_FLOAT goto generate_sub_floats
if *1p == TYPE_DOUBLE goto generate_sub_doubles
p = types + type2
if *1p == TYPE_POINTER goto generate_sub_pointers
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
scale_rax_for_addition_with(type1) ; in case this is a pointer - integer subtraction
emit_mov_reg(REG_RSI, REG_RAX) ; mov rsi, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_mov_reg(REG_RBX, REG_RSI) ; mov rbx, rsi
emit_sub_rax_rbx() ; sub rax, rbx
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, out_type)
return
:generate_sub_pointers
; pointer difference - need to divide by object size
local sz1
local sz2
p = types + type1
if *1p != TYPE_POINTER goto bad_pointer_diff
p = type1 + 1
sz1 = type_sizeof(p)
p = type2 + 1
sz2 = type_sizeof(p)
if sz1 != sz2 goto bad_pointer_diff
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RSI, REG_RAX) ; mov rsi, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_mov_reg(REG_RBX, REG_RSI) ; mov rbx, rsi
emit_sub_rax_rbx() ; sub rax, rbx
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_rbx_imm64(sz1) ; mov rbx, (object size)
emit_zero_rdx() ; xor edx, edx
emit_div_rbx() ; div rbx
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
:bad_pointer_diff
statement_error(statement, .str_bad_pointer_diff)
:str_bad_pointer_diff
string Subtraction of incompatible pointer types.
byte 0
:generate_sub_floats
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_cvtss2sd_xmm0_xmm0() ; cvtss2sd xmm0, xmm0
emit_movq_xmm1_xmm0() ; movq xmm1, xmm0
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_cvtss2sd_xmm0_xmm0() ; cvtss2sd xmm0, xmm0
emit_subsd_xmm0_xmm1() ; subsd xmm0, xmm1
emit_cvtsd2ss_xmm0_xmm0() ; cvtsd2ss xmm0, xmm0
emit_movq_rax_xmm0() ; movq rax, xmm0
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
:generate_sub_doubles
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_movq_xmm1_rax() ; movq xmm1, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_subsd_xmm0_xmm1() ; subsd xmm0, xmm1
emit_movq_rax_xmm0() ; movq rax, xmm0
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
; pop the top two things off of the stack, and push their product
function generate_stack_mul
argument statement ; for errors
argument type
local p
p = types + type
if *1p == TYPE_FLOAT goto generate_mul_floats
if *1p == TYPE_DOUBLE goto generate_mul_doubles
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_mul_rbx() ; mul rbx
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
:generate_mul_floats
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_cvtss2sd_xmm0_xmm0() ; cvtss2sd xmm0, xmm0
emit_movq_xmm1_xmm0() ; movq xmm1, xmm0
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_cvtss2sd_xmm0_xmm0() ; cvtss2sd xmm0, xmm0
emit_mulsd_xmm0_xmm1() ; mulsd xmm0, xmm1
emit_cvtsd2ss_xmm0_xmm0() ; cvtsd2ss xmm0, xmm0
emit_movq_rax_xmm0() ; movq rax, xmm0
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
:generate_mul_doubles
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_movq_xmm1_rax() ; movq xmm1, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_mulsd_xmm0_xmm1() ; mulsd xmm0, xmm1
emit_movq_rax_xmm0() ; movq rax, xmm0
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
; pop the top two things off of the stack, and push their quotient
function generate_stack_div
argument statement ; for errors
argument type
local p
local c
p = types + type
if *1p == TYPE_FLOAT goto generate_div_floats
if *1p == TYPE_DOUBLE goto generate_div_doubles
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
c = *1p & 1
if c == 1 goto generate_div_signed
emit_zero_rdx() ; xor edx, edx
emit_div_rbx() ; div rbx
goto generate_div_cont
:generate_div_signed
emit_cqo() ; cqo
emit_idiv_rbx() ; idiv rbx
:generate_div_cont
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
:generate_div_floats
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_cvtss2sd_xmm0_xmm0() ; cvtss2sd xmm0, xmm0
emit_movq_xmm1_xmm0() ; movq xmm1, xmm0
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_cvtss2sd_xmm0_xmm0() ; cvtss2sd xmm0, xmm0
emit_divsd_xmm0_xmm1() ; divsd xmm0, xmm1
emit_cvtsd2ss_xmm0_xmm0() ; cvtsd2ss xmm0, xmm0
emit_movq_rax_xmm0() ; movq rax, xmm0
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
:generate_div_doubles
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_movq_xmm1_rax() ; movq xmm1, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_divsd_xmm0_xmm1() ; divsd xmm0, xmm1
emit_movq_rax_xmm0() ; movq rax, xmm0
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return
; pop the top two things off of the stack, and push their remainder
function generate_stack_remainder
argument statement ; for errors
argument type
local p
local c
p = types + type
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
c = *1p & 1
if c == 1 goto generate_remainder_signed
emit_zero_rdx() ; xor edx, edx
emit_div_rbx() ; div rbx
emit_mov_reg(REG_RAX, REG_RDX) ; mov rax, rdx
goto generate_remainder_cont
:generate_remainder_signed
emit_cqo() ; cqo
emit_idiv_rbx() ; idiv rbx
emit_mov_reg(REG_RAX, REG_RDX) ; mov rax, rdx
:generate_remainder_cont
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
; pop the top two things off of the stack, and push their bitwise and
function generate_stack_bitwise_and
argument statement ; for errors
argument type
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_and_rax_rbx() ; and rax, rbx
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
; pop the top two things off of the stack, and push their bitwise or
function generate_stack_bitwise_or
argument statement ; for errors
argument type
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_or_rax_rbx() ; or rax, rbx
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
; pop the top two things off of the stack, and push their bitwise xor
function generate_stack_bitwise_xor
argument statement ; for errors
argument type
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_xor_rax_rbx() ; xor rax, rbx
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
function generate_stack_lshift
argument statement ; for errors
argument type
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RCX, REG_RAX) ; mov rcx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
emit_shl_rax_cl() ; shl rax, cl
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
function generate_stack_rshift
argument statement ; for errors
argument type
local p
local c
p = types + type
c = *1p & 1
emit_mov_rax_qword_rsp_plus_imm32(0) ; mov rax, [rsp] (second operand)
emit_mov_reg(REG_RCX, REG_RAX) ; mov rcx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8] (first operand)
if c == 1 goto gen_rshift_signed
emit_shr_rax_cl() ; shr rax, cl
goto gen_rshift_cont
:gen_rshift_signed
emit_sar_rax_cl() ; sar rax, cl
:gen_rshift_cont
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
; pop a pointer off of the stack, then push the dereferenced value according to `type`
function generate_stack_dereference
argument statement ; for errors
argument type
local p
local size
local c
size = type_sizeof(type)
if size == 1 goto gen_deref1
if size == 2 goto gen_deref2
if size == 4 goto gen_deref4
if size == 8 goto gen_deref8
emit_pop_rax() ; pop rax
emit_mov_reg(REG_RSI, REG_RAX) ; mov rsi, rax
c = round_up_to_8(size)
emit_sub_rsp_imm32(c) ; sub rsp, (size)
emit_mov_reg(REG_RDI, REG_RSP) ; mov rdi, rsp
emit_mov_rax_imm64(size) ; mov rax, (size)
emit_mov_reg(REG_RCX, REG_RAX) ; mov rcx, rax
emit_rep_movsb() ; rep movsb
return
:gen_deref_cast
emit_mov_qword_rsp_rax()
p = types + type
if *1p >= TYPE_LONG goto return_0
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return
:gen_deref1
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_al_byte_rbx() ; mov al, [rbx]
goto gen_deref_cast
:gen_deref2
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_ax_word_rbx() ; mov ax, [rbx]
goto gen_deref_cast
:gen_deref4
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_eax_dword_rbx() ; mov eax, [rbx]
goto gen_deref_cast
:gen_deref8
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rbx() ; mov rax, [rbx]
goto gen_deref_cast
; pop address off of stack, pop value, set *address to value, then push value
function generate_stack_assign
argument statement
argument type
local size
size = type_sizeof(type)
if size == 1 goto gen_assign1
if size == 2 goto gen_assign2
if size == 4 goto gen_assign4
if size == 8 goto gen_assign8
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RDI, REG_RAX) ; mov rdi, rax
emit_add_rsp_imm32(8) ; add rsp, 8
emit_mov_reg(REG_RSI, REG_RSP) ; mov rsi, rsp
emit_mov_rax_imm64(size) ; mov rax, (size)
emit_mov_reg(REG_RCX, REG_RAX) ; mov rcx, rax
emit_rep_movsb() ; rep movsb
return
:gen_assign_ret
emit_add_rsp_imm32(8) ; pop address
return
:gen_assign1
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8]
emit_mov_byte_rbx_al() ; mov [rbx], al
goto gen_assign_ret
:gen_assign2
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8]
emit_mov_word_rbx_ax() ; mov [rbx], ax
goto gen_assign_ret
:gen_assign4
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8]
emit_mov_dword_rbx_eax() ; mov [rbx], eax
goto gen_assign_ret
:gen_assign8
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_qword_rsp_plus_imm32(8) ; mov rax, [rsp+8]
emit_mov_qword_rbx_rax() ; mov [rbx], rax
goto gen_assign_ret
; returns pointer to end of expr
function generate_push_address_of_expression
argument statement ; for errors
argument expr
local c
local d
c = *1expr
if c == EXPRESSION_GLOBAL_VARIABLE goto addrof_global_var
if c == EXPRESSION_LOCAL_VARIABLE goto addrof_local_var
if c == EXPRESSION_DEREFERENCE goto addrof_dereference
if c == EXPRESSION_SUBSCRIPT goto addrof_subscript
if c == EXPRESSION_DOT goto addrof_dot
if c == EXPRESSION_ARROW goto addrof_arrow
statement_error(statement, .str_bad_lvalue)
:str_bad_lvalue
string Bad l-value.
byte 0
:addrof_global_var
expr += 8
emit_mov_rax_imm64(*4expr)
emit_push_rax()
expr += 8
return expr
:addrof_local_var
expr += 8
emit_lea_rax_rbp_plus_imm32(*4expr)
emit_push_rax()
expr += 8
return expr
:addrof_dereference
expr += 8
return generate_push_expression(statement, expr)
:addrof_subscript
expr += 8
c = expr + 4 ; type 1
c = *4c
expr = generate_push_expression(statement, expr)
d = expr + 4 ; type 2
d = *4d
expr = generate_push_expression(statement, expr)
generate_stack_add(statement, c, d, c)
return expr
:addrof_dot
expr += 8
expr = generate_push_address_of_expression(statement, expr)
goto addrof_dot_cont
:addrof_arrow
expr += 8
expr = generate_push_expression(statement, expr)
:addrof_dot_cont
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_imm64(*8expr) ; mov rax, (offset to member)
emit_add_rax_rbx() ; add rax, rbx
emit_mov_qword_rsp_rax() ; mov [rsp], rax
expr += 8
return expr
; `statement` is used for errors
; returns pointer to end of expression
function generate_push_expression
argument statement
argument expr
local b
local c
local d
local p
local type
type = expr + 4
type = *4type
c = *1expr
if c == EXPRESSION_CONSTANT_INT goto generate_int
if c == EXPRESSION_CONSTANT_FLOAT goto generate_float
if c == EXPRESSION_CAST goto generate_cast
if c == EXPRESSION_UNARY_PLUS goto generate_cast ; the unary plus operator just casts to the promoted type
if c == EXPRESSION_UNARY_MINUS goto generate_unary_minus
if c == EXPRESSION_BITWISE_NOT goto generate_unary_bitwise_not
if c == EXPRESSION_LOGICAL_NOT goto generate_unary_logical_not
if c == EXPRESSION_ADD goto generate_add
if c == EXPRESSION_SUB goto generate_sub
if c == EXPRESSION_MUL goto generate_mul
if c == EXPRESSION_DIV goto generate_div
if c == EXPRESSION_REMAINDER goto generate_remainder
if c == EXPRESSION_BITWISE_AND goto generate_bitwise_and
if c == EXPRESSION_BITWISE_OR goto generate_bitwise_or
if c == EXPRESSION_BITWISE_XOR goto generate_bitwise_xor
if c == EXPRESSION_LSHIFT goto generate_lshift
if c == EXPRESSION_RSHIFT goto generate_rshift
if c == EXPRESSION_GLOBAL_VARIABLE goto generate_global_variable
if c == EXPRESSION_LOCAL_VARIABLE goto generate_local_variable
if c == EXPRESSION_DEREFERENCE goto generate_dereference
if c == EXPRESSION_SUBSCRIPT goto generate_subscript
if c == EXPRESSION_ADDRESS_OF goto generate_address_of
if c == EXPRESSION_DOT goto generate_dot_or_arrow
if c == EXPRESSION_ARROW goto generate_dot_or_arrow
if c == EXPRESSION_COMMA goto generate_comma
if c == EXPRESSION_ASSIGN goto generate_assign
die(.str_genpushexprNI)
:str_genpushexprNI
string generate_push_expression not implemented.
byte 0
:generate_cast
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
return expr
:generate_unary_minus
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
p = types + type
if *1p == TYPE_FLOAT goto generate_unary_minus_float
if *1p == TYPE_DOUBLE goto generate_unary_minus_double
; it's just an integer
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_neg_rax() ; neg rax
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return expr
; "negate(x) copies a floating-point operand x to a destination in the same format, reversing the sign bit." IEEE 754 § 5.5.1
:generate_unary_minus_float
c = 1 < 31 ; sign bit for floats
goto generate_unary_minus_floating
:generate_unary_minus_double
c = 1 < 63 ; sign bit for doubles
:generate_unary_minus_floating
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_mov_reg(REG_RBX, REG_RAX) ; mov rbx, rax
emit_mov_rax_imm64(c) ; mov rax, (sign bit)
emit_xor_rax_rbx() ; xor rax, rbx
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return expr
:generate_unary_bitwise_not
expr += 8
expr = generate_push_expression(statement, expr) ; we'll cast after we take the bitwise not.
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_not_rax() ; not rax
emit_mov_qword_rsp_rax() ; mov [rsp], rax
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return expr
:generate_address_of
expr += 8
expr = generate_push_address_of_expression(statement, expr)
return expr
:generate_assign
expr += 8
b = type_is_array(type)
if b != 0 goto assign_array
p = expression_get_end(expr)
c = p
; it makes things a lot easier if we push the rhs of the assignment first -- also
; *f() = g()
; it might be required to call g first? (something something sequence points)
p = generate_push_expression_casted(statement, p, type)
d = generate_push_address_of_expression(statement, expr)
if c != d goto exprend_wrong
expr = p
generate_stack_assign(statement, type)
return expr
:assign_array
statement_error(statement, .str_assign_array)
:str_assign_array
string Assigning to array.
byte 0
:exprend_wrong
die(.str_exprend_wrong)
:str_exprend_wrong
string Internal compiler error: expression_get_end disagrees with generate_push_expression.
byte 0
:generate_add
expr += 8
c = expr + 4 ; type of 1st operand
expr = generate_push_expression_casted(statement, expr, type)
d = expr + 4 ; type of 2nd operand
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_add(statement, *4c, *4d, type)
return expr
:generate_sub
expr += 8
c = expr + 4 ; type of 1st operand
expr = generate_push_expression_casted(statement, expr, type)
d = expr + 4 ; type of 2nd operand
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_sub(statement, *4c, *4d, type)
return expr
:generate_mul
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_mul(statement, type)
return expr
:generate_div
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_div(statement, type)
return expr
:generate_remainder
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_remainder(statement, type)
return expr
:generate_bitwise_and
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_bitwise_and(statement, type)
return expr
:generate_bitwise_or
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_bitwise_or(statement, type)
return expr
:generate_bitwise_xor
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_bitwise_xor(statement, type)
return expr
:generate_lshift
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_lshift(statement, type)
return expr
:generate_rshift
expr += 8
expr = generate_push_expression_casted(statement, expr, type)
expr = generate_push_expression_casted(statement, expr, type)
generate_stack_rshift(statement, type)
return expr
:generate_unary_logical_not
expr += 8
p = expr + 4
p = types + *4p
if *1p == TYPE_FLOAT goto generate_logical_not_floating
if *1p == TYPE_DOUBLE goto generate_logical_not_floating
expr = generate_push_expression(statement, expr)
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_test_rax_rax() ; test rax, rax
:generate_logical_not_cont
emit_je_rel32(7) ; je +7 (2 bytes for xor eax, eax; 5 bytes for jmp +10)
emit_zero_rax() ; xor eax, eax
emit_jmp_rel32(10) ; jmp +10 (10 bytes for mov rax, 1)
emit_mov_rax_imm64(1) ; mov rax, 1
emit_mov_qword_rsp_rax() ; mov [rsp], rax
return expr
:generate_logical_not_floating
; we want !-0.0 to be 1, so this needs to be a separate case
expr = generate_push_expression_casted(statement, expr, TYPE_DOUBLE) ; cast floats to doubles when comparing
emit_zero_rax() ; xor eax, eax
emit_movq_xmm1_rax() ; movq xmm1, rax
emit_mov_rax_qword_rsp() ; mov rax, [rsp]
emit_movq_xmm0_rax() ; movq xmm0, rax
emit_comisd_xmm0_xmm1() ; comisd xmm0, xmm1
goto generate_logical_not_cont
:generate_global_variable
expr += 8
d = *4expr ; address
expr += 4
b = *4expr ; is array?
expr += 4
if b != 0 goto global_var_array
c = type_sizeof(type)
if c > 8 goto global_var_large
emit_mov_rbx_imm64(d) ; mov rbx, (address)
emit_mov_rax_qword_rbx() ; mov rax, [rbx]
emit_push_rax() ; push rax
p = types + type
if *1p < TYPE_LONG goto global_var_needs_cast
return expr
:global_var_needs_cast
; we need to sign extend 8/16/32-bit signed global variables to 64 bits
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return expr
:global_var_large
c = round_up_to_8(c)
emit_sub_rsp_imm32(c) ; sub rsp, (size)
emit_mov_reg(REG_RDI, REG_RSP) ; mov rdi, rsp
emit_mov_rax_imm64(d) ; mov rax, (address)
emit_mov_reg(REG_RSI, REG_RAX) ; mov rsi, rax
emit_mov_rax_imm64(c) ; mov rax, (size)
emit_mov_reg(REG_RCX, REG_RAX) ; mov rcx, rax
emit_rep_movsb() ; rep movsb
return expr
:global_var_array
; just push the address of the array
emit_mov_rax_imm64(d) ; mov rax, (address)
emit_push_rax() ; push rax
return expr
:generate_dereference
expr += 8
expr = generate_push_expression(statement, expr)
generate_stack_dereference(statement, type)
return expr
:generate_subscript
expr += 8
c = expr + 4 ; type 1
c = *4c
expr = generate_push_expression(statement, expr)
d = expr + 4 ; type 2
d = *4d
expr = generate_push_expression(statement, expr)
generate_stack_add(statement, c, d, c)
generate_stack_dereference(statement, type)
return expr
:generate_dot_or_arrow
; @NONSTANDARD: we require that the 1st operand to . be an lvalue
; e.g. int thing = function_which_returns_struct().x;
; is not allowed
expr = generate_push_address_of_expression(statement, expr)
generate_stack_dereference(statement, type)
return expr
:generate_local_variable
expr += 8
d = sign_extend_32_to_64(*4expr) ; rbp offset
expr += 4
b = *4expr ; is array?
expr += 4
if b != 0 goto local_var_array
c = type_sizeof(type)
if c > 8 goto local_var_large
emit_mov_rax_qword_rbp_plus_imm32(d) ; mov rax, [rbp+X]
emit_push_rax() ; push rax
p = types + type
if *1p < TYPE_LONG goto local_var_needs_cast
return expr
:local_var_needs_cast
generate_cast_top_of_stack(statement, TYPE_UNSIGNED_LONG, type)
return expr
:local_var_large
c = round_up_to_8(c)
emit_sub_rsp_imm32(c) ; sub rsp, (size)
emit_mov_reg(REG_RDI, REG_RSP) ; mov rdi, rsp
emit_lea_rax_rbp_plus_imm32(d) ; lea rax, [rbp+X]
emit_mov_reg(REG_RSI, REG_RAX) ; mov rsi, rax
emit_mov_rax_imm64(c) ; mov rax, (size)
emit_mov_reg(REG_RCX, REG_RAX) ; mov rcx, rax
emit_rep_movsb() ; rep movsb
return expr
:local_var_array
; push address of array instead of array
emit_lea_rax_rbp_plus_imm32(d) ; lea rax, [rbp+X]
emit_push_rax() ; push rax
return expr
:generate_float
expr += 8
emit_mov_rax_imm64(*8expr)
emit_push_rax()
generate_cast_top_of_stack(statement, TYPE_DOUBLE, type)
expr += 8
return expr
:generate_int
expr += 8
emit_mov_rax_imm64(*8expr)
emit_push_rax()
expr += 8
return expr
:generate_comma
expr += 8
c = expr + 4 ; type of 1st expression
c = *4c
expr = generate_push_expression(statement, expr)
c = type_sizeof(c)
c = round_up_to_8(c)
emit_add_rsp_imm32(c) ; add rsp, (size of expression value on stack)
expr = generate_push_expression(statement, expr)
return expr
function generate_statement
argument statement
local dat1
local dat2
local dat3
local dat4
local n
local p
local c
dat1 = statement + 8
dat1 = *8dat1
dat2 = statement + 16
dat2 = *8dat2
dat3 = statement + 24
dat3 = *8dat3
dat4 = statement + 32
dat4 = *8dat4
c = *1statement
if c == STATEMENT_BLOCK goto gen_block
if c == STATEMENT_RETURN goto gen_return
if c == STATEMENT_LOCAL_DECLARATION goto gen_local_decl
if c == STATEMENT_EXPRESSION goto gen_stmt_expr
; @TODO
die(.str_genstmtNI)
:str_genstmtNI
string generate_statement not implemented.
byte 0
:gen_block
:gen_block_loop
if *1dat1 == 0 goto gen_block_loop_end
generate_statement(dat1)
dat1 += 40
goto gen_block_loop
:gen_block_loop_end
return
:gen_return
if dat1 == 0 goto gen_return_noexpr
generate_push_expression_casted(statement, dat1, curr_function_return_type)
; copy sizeof(return expression) rounded up to 8 bytes from [rsp] to [rbp+16]
emit_mov_reg(REG_RSI, REG_RSP)
emit_lea_rax_rbp_plus_imm32(16)
emit_mov_reg(REG_RDI, REG_RAX)
generate_copy_rsi_to_rdi_qwords(curr_function_return_type)
:gen_return_noexpr
generate_return()
return
:gen_local_decl
c = type_sizeof(dat2)
c = round_up_to_8(c)
if dat3 != 0 goto gen_local_decl_initializer
; move the stack pointer to the start of the variable
dat1 += c
dat1 = 0 - dat1
emit_lea_rsp_rbp_plus_imm32(dat1)
if dat4 != 0 goto gen_local_decl_data_initializer
return
:gen_local_decl_initializer
dat1 = 0 - dat1
; move the stack pointer to the end of the variable
emit_lea_rsp_rbp_plus_imm32(dat1)
; push the expression
generate_push_expression_casted(statement, dat3, dat2)
return
:gen_local_decl_data_initializer
emit_mov_rax_imm64(dat4) ; mov rax, (data address)
emit_mov_reg(REG_RSI, REG_RAX) ; mov rsi, rax
emit_mov_reg(REG_RDI, REG_RSP) ; mov rdi, rsp
emit_mov_rax_imm64(c) ; mov rax, (size)
emit_mov_reg(REG_RCX, REG_RAX) ; mov rcx, rax
emit_rep_movsb() ; rep movsb
return
:gen_stmt_expr
generate_push_expression_casted(statement, dat1, TYPE_VOID)
; since we casted to void, it'll always be 8 bytes on the stack
emit_add_rsp_imm32(8)
return
function generate_function
argument function_name
argument function_statement
local function_type
local out0
function_type = ident_list_lookup(function_types, function_name)
curr_function_return_type = functype_return_type(function_type)
if codegen_second_pass != 0 goto genf_second_pass
curr_function_labels = ident_list_create(4000) ; ~ 200 labels per function should be plenty
ident_list_add(functions_labels, function_name, curr_function_labels)
goto genf_cont
:genf_second_pass
curr_function_labels = ident_list_lookup(functions_labels, function_name)
:genf_cont
; prologue
emit_sub_rsp_imm32(8)
emit_mov_qword_rsp_rbp()
emit_mov_reg(REG_RBP, REG_RSP)
generate_statement(function_statement)
; implicit return at end of function
generate_return()
return
function generate_functions
local addr
local c
local p
local function_name
function_name = function_statements
:genfunctions_loop
if *1function_name == 0 goto genfunctions_loop_end
addr = code_output - output_file_data ; address of this function
if codegen_second_pass != 0 goto genfs_check_addr
; first pass; record address of function
ident_list_add(functions_addresses, function_name, addr)
goto genfs_cont
:genfs_check_addr
c = ident_list_lookup(functions_addresses, function_name)
if c != addr goto function_addr_mismatch
goto genfs_cont
:genfs_cont
p = memchr(function_name, 0)
p += 1
generate_function(function_name, *8p)
function_name = p + 8
goto genfunctions_loop
:genfunctions_loop_end
return
:function_addr_mismatch
; address of function on 2nd pass doesn't line up with 1st pass
puts(.str_function_addr_mismatch)
puts(function_name)
exit(1)
:str_function_addr_mismatch
string Function address on first pass doesn't match 2nd pass:
byte 32
byte 0
; emit ELF header and code.
function generate_code
code_output = output_file_data
emit_qword(0x00010102464c457f) ; elf identifier, 64-bit little endian, ELF version 1
emit_qword(0) ; reserved
emit_word(2) ; executable file
emit_word(0x3e) ; architecture x86-64
emit_dword(1) ; ELF version 1
emit_qword(ENTRY_ADDR) ; entry point
emit_qword(0x40) ; program header table offset
emit_qword(0) ; section header table offset
emit_dword(0) ; flags
emit_word(0x40) ; size of header
emit_word(0x38) ; size of program header
emit_word(3) ; # of program headers = 3 (code, rwdata, rodata)
emit_word(0) ; size of section header
emit_word(0) ; # of section headers
emit_word(0) ; index of .shstrtab
; from /usr/include/elf.h:
;#define PF_X (1 << 0) /* Segment is executable */
;#define PF_W (1 << 1) /* Segment is writable */
;#define PF_R (1 << 2) /* Segment is readable */
; program header 1 (code)
emit_dword(1) ; loadable segment
emit_dword(1) ; execute only
emit_qword(ENTRY_ADDR) ; offset in file
emit_qword(ENTRY_ADDR) ; virtual address
emit_qword(0) ; physical address
emit_qword(TOTAL_CODE_SIZE) ; size in executable file
emit_qword(TOTAL_CODE_SIZE) ; size when loaded into memory
emit_qword(4096) ; alignment
; program header 2 (rodata)
emit_dword(1) ; loadable segment
emit_dword(4) ; read only
emit_qword(RODATA_ADDR) ; offset in file
emit_qword(RODATA_ADDR) ; virtual address
emit_qword(0) ; physical address
emit_qword(RODATA_SIZE) ; size in executable file
emit_qword(RODATA_SIZE) ; size when loaded into memory
emit_qword(4096) ; alignment
; program header 3 (rwdata)
emit_dword(1) ; loadable segment
emit_dword(6) ; read/write
emit_qword(RWDATA_ADDR) ; offset in file
emit_qword(RWDATA_ADDR) ; virtual address
emit_qword(0) ; physical address
emit_qword(RWDATA_SIZE) ; size in executable file
emit_qword(RWDATA_SIZE) ; size when loaded into memory
emit_qword(4096) ; alignment
local p_func
code_output = output_file_data + FUNCTIONS_ADDR
codegen_second_pass = 0
generate_functions()
code_output = output_file_data + FUNCTIONS_ADDR
codegen_second_pass = 1
generate_functions()
; generate code at the entry point of the executable
local main_addr
main_addr = ident_list_lookup(functions_addresses, .str_main)
if main_addr == 0 goto no_main_function
; on entry, we will have:
; argc = *rsp
; argv = rsp + 8
code_output = output_file_data + ENTRY_ADDR
; add rsp, 8
emit_add_rsp_imm32(8)
; mov rax, rsp (set rax to argv)
emit_mov_reg(REG_RAX, REG_RSP)
; sub rsp, 32 (undo add rsp, 8 from before and add space for argv, argc, return value)
emit_sub_rsp_imm32(32)
; mov [rsp+16], rax (put argv in the right place)
emit_mov_qword_rsp_plus_imm32_rax(16)
; mov rax, [rsp+24] (set rax to argc)
emit_mov_rax_qword_rsp_plus_imm32(24)
; mov [rsp+8], rax (put argc in the right place)
emit_mov_qword_rsp_plus_imm32_rax(8)
; mov rax, main
emit_mov_rax_imm64(main_addr)
; call rax
emit_call_rax()
; mov rax, [rsp]
emit_mov_rax_qword_rsp()
; mov rdi, rax
emit_mov_reg(REG_RDI, REG_RAX)
; mov rax, 0x3c (SYS_exit)
emit_mov_rax_imm64(0x3c)
; syscall
emit_syscall()
return
:no_main_function
die(.str_no_main_function)
:str_no_main_function
string Error: No main function.
byte 0
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