diff options
Diffstat (limited to 'executor/x86_64/executor.c')
| -rw-r--r-- | executor/x86_64/executor.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/executor/x86_64/executor.c b/executor/x86_64/executor.c index c442da8..f747e4a 100644 --- a/executor/x86_64/executor.c +++ b/executor/x86_64/executor.c @@ -284,6 +284,7 @@ int amal_exec_call(amal_executor *self, u32 code_offset, u8 num_args, i8 dst_reg isize asm_offset = asm_get_size(&impl->asm); ASM_ENSURE_CAPACITY + assert(num_args % 2 == 0 && "TODO: Align stack to 16-bytes before calling functions"); assert(code_offset < asm_offset); asm_call_rel32(&impl->asm, (isize)code_offset - asm_offset); @@ -318,7 +319,8 @@ int amal_exec_calle(amal_executor *self, void *func, u8 num_args, i8 dst_reg) { AsmPtr dst; IMPL_START - /* TODO: Support R and XMM registers so more than 5 arguments can be used for functions */ + assert(num_args % 2 == 0 && "TODO: Align stack to 16-bytes before calling functions"); + /* TODO: Support R and XMM registers so more than 4 arguments can be used for functions */ assert(num_args < 5); { /* @@ -427,6 +429,10 @@ int amal_exec_ret(amal_executor *self, i8 reg) { return amal_exec_func_end(self); } +static u32 get_next_uneven_number(u32 value) { + return value + !(value & 1); +} + int amal_exec_func_start(amal_executor *self, u16 num_regs) { /* TODO: Validate stack size, or maybe remove all validation? do we really need validation? @@ -443,7 +449,11 @@ int amal_exec_func_start(amal_executor *self, u16 num_regs) { asm_pushr(&impl->asm, RBX); asm_pushr(&impl->asm, RBP); asm_mov_rr(&impl->asm, RBP, RSP); - asm_sub_rm64_imm(&impl->asm, RSP, num_regs * sizeof(isize)); + /* + Functions are entered with a stack alignment of 8 (because of call return address is pushed to stack). + Make sure to align to to next 16-byte even if the extra bytes are not used. + */ + asm_sub_rm64_imm(&impl->asm, RSP, get_next_uneven_number(num_regs) * sizeof(isize)); return 0; } |