diff options
| author | Damien George <damien.p.george@gmail.com> | 2019-12-22 23:10:55 +1100 |
|---|---|---|
| committer | Damien George <damien.p.george@gmail.com> | 2019-12-27 12:30:51 +1100 |
| commit | b97fb683d0923d29f55cf54fc2fd5cc19186536e (patch) | |
| tree | 1e53efc3a6d4384c4d52051ac4ac122aa8b15a8b | |
| parent | ed2be79b4930f620083256fcb5b4faf9091c9ffc (diff) | |
py/asmx86: Fix stack to be 16-byte aligned for entry and sub-call.
| -rw-r--r-- | py/asmx86.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/py/asmx86.c b/py/asmx86.c index 23160c9c2..e4736251f 100644 --- a/py/asmx86.c +++ b/py/asmx86.c @@ -403,7 +403,7 @@ void asm_x86_entry(asm_x86_t *as, int num_locals) { asm_x86_push_r32(as, ASM_X86_REG_EBX); asm_x86_push_r32(as, ASM_X86_REG_ESI); asm_x86_push_r32(as, ASM_X86_REG_EDI); - num_locals |= 1; // make it odd so stack is aligned on 16 byte boundary + num_locals |= 3; // make it odd so stack is aligned on 16 byte boundary asm_x86_sub_r32_i32(as, ASM_X86_REG_ESP, num_locals * WORD_SIZE); as->num_locals = num_locals; } @@ -497,8 +497,14 @@ void asm_x86_push_local_addr(asm_x86_t *as, int local_num, int temp_r32) #endif void asm_x86_call_ind(asm_x86_t *as, size_t fun_id, mp_uint_t n_args, int temp_r32) { - // TODO align stack on 16-byte boundary before the call assert(n_args <= 5); + + // Align stack on 16-byte boundary during the call + unsigned int align = ((n_args + 3) & ~3) - n_args; + if (align) { + asm_x86_sub_r32_i32(as, ASM_X86_REG_ESP, align * WORD_SIZE); + } + if (n_args > 4) { asm_x86_push_r32(as, ASM_X86_REG_ARG_5); } @@ -521,7 +527,7 @@ void asm_x86_call_ind(asm_x86_t *as, size_t fun_id, mp_uint_t n_args, int temp_r // the caller must clean up the stack if (n_args > 0) { - asm_x86_add_i32_to_r32(as, WORD_SIZE * n_args, ASM_X86_REG_ESP); + asm_x86_add_i32_to_r32(as, (n_args + align) * WORD_SIZE, ASM_X86_REG_ESP); } } |