diff options
Diffstat (limited to '05/codegen.b')
| -rw-r--r-- | 05/codegen.b | 118 |
1 files changed, 114 insertions, 4 deletions
diff --git a/05/codegen.b b/05/codegen.b index 304b612..1f0d077 100644 --- a/05/codegen.b +++ b/05/codegen.b @@ -150,12 +150,41 @@ function emit_call_rax code_output += 2 return +function emit_push_rax + ; 50 + *1code_output = 0x50 + 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_rep_movsb + ; f3 a4 + *2code_output = 0xa4f3 + code_output += 2 + return + +function emit_movsq + ; 48 a5 + *2code_output = 0xa548 + code_output += 2 + 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) @@ -164,11 +193,92 @@ function generate_return emit_ret() return +; returns pointer to end of expression +function generate_push_expression + argument expr + local c + c = *1expr + if c == EXPRESSION_CONSTANT_INT goto generate_push_int + + die(.str_genpushexprNI) + :str_genpushexprNI + string generate_push_expression not implemented. + byte 0 + :generate_push_int + expr += 8 + emit_mov_rax_imm64(*8expr) + emit_push_rax() + expr += 8 + return expr + +; 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 + 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 ; @TODO - return - + 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(dat1) + ; 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) + p = dat1 + 4 + generate_copy_rsi_to_rdi_qwords(*4p) + + :gen_return_noexpr + generate_return() + return function generate_function argument function_name argument function_statement @@ -185,7 +295,7 @@ function generate_function ; prologue emit_sub_rsp_imm32(8) emit_mov_qword_rsp_rbp() - emit_mov_reg(REG_RBP, REG_RSP) + emit_mov_reg(REG_RBP, REG_RSP) generate_statement(function_statement) @@ -216,7 +326,7 @@ function generate_functions :genfs_cont p = memchr(function_name, 0) p += 1 - generate_function(function_name, p) + generate_function(function_name, *8p) function_name = p + 8 goto genfunctions_loop :genfunctions_loop_end |