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circuitpython/py/asmthumb.c
Damien George 9988618e0e py: Implement full func arg passing for native emitter. 
This patch gets full function argument passing working with native
emitter.  Includes named args, keyword args, default args, var args
and var keyword args.  Fully Python compliant.

It reuses the bytecode mp_setup_code_state function to do all the hard
work.  This function is slightly adjusted to accommodate native calls,
and the native emitter is forced a bit to emit similar prelude and
code-info as bytecode.
2015-04-07 22:43:28 +01:00

464 lines
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/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdio.h>
#include <assert.h>
#include <string.h>
#include "py/mpconfig.h"
// wrapper around everything in this file
#if MICROPY_EMIT_THUMB || MICROPY_EMIT_INLINE_THUMB
#include "py/asmthumb.h"
#define UNSIGNED_FIT8(x) (((x) & 0xffffff00) == 0)
#define UNSIGNED_FIT16(x) (((x) & 0xffff0000) == 0)
#define SIGNED_FIT8(x) (((x) & 0xffffff80) == 0) || (((x) & 0xffffff80) == 0xffffff80)
#define SIGNED_FIT9(x) (((x) & 0xffffff00) == 0) || (((x) & 0xffffff00) == 0xffffff00)
#define SIGNED_FIT12(x) (((x) & 0xfffff800) == 0) || (((x) & 0xfffff800) == 0xfffff800)
#define SIGNED_FIT23(x) (((x) & 0xffc00000) == 0) || (((x) & 0xffc00000) == 0xffc00000)
struct _asm_thumb_t {
mp_uint_t pass;
mp_uint_t code_offset;
mp_uint_t code_size;
byte *code_base;
byte dummy_data[4];
mp_uint_t max_num_labels;
mp_uint_t *label_offsets;
mp_uint_t push_reglist;
mp_uint_t stack_adjust;
};
asm_thumb_t *asm_thumb_new(uint max_num_labels) {
asm_thumb_t *as;
as = m_new0(asm_thumb_t, 1);
as->max_num_labels = max_num_labels;
as->label_offsets = m_new(mp_uint_t, max_num_labels);
return as;
}
void asm_thumb_free(asm_thumb_t *as, bool free_code) {
if (free_code) {
MP_PLAT_FREE_EXEC(as->code_base, as->code_size);
}
m_del(mp_uint_t, as->label_offsets, as->max_num_labels);
m_del_obj(asm_thumb_t, as);
}
void asm_thumb_start_pass(asm_thumb_t *as, uint pass) {
if (pass == ASM_THUMB_PASS_COMPUTE) {
memset(as->label_offsets, -1, as->max_num_labels * sizeof(mp_uint_t));
} else if (pass == ASM_THUMB_PASS_EMIT) {
MP_PLAT_ALLOC_EXEC(as->code_offset, (void**)&as->code_base, &as->code_size);
if (as->code_base == NULL) {
assert(0);
}
//printf("code_size: %u\n", as->code_size);
}
as->pass = pass;
as->code_offset = 0;
}
void asm_thumb_end_pass(asm_thumb_t *as) {
// could check labels are resolved...
}
// all functions must go through this one to emit bytes
// if as->pass < ASM_THUMB_PASS_EMIT, then this function only returns a buffer of 4 bytes length
STATIC byte *asm_thumb_get_cur_to_write_bytes(asm_thumb_t *as, int num_bytes_to_write) {
//printf("emit %d\n", num_bytes_to_write);
if (as->pass < ASM_THUMB_PASS_EMIT) {
as->code_offset += num_bytes_to_write;
return as->dummy_data;
} else {
assert(as->code_offset + num_bytes_to_write <= as->code_size);
byte *c = as->code_base + as->code_offset;
as->code_offset += num_bytes_to_write;
return c;
}
}
uint asm_thumb_get_code_pos(asm_thumb_t *as) {
return as->code_offset;
}
uint asm_thumb_get_code_size(asm_thumb_t *as) {
return as->code_size;
}
void *asm_thumb_get_code(asm_thumb_t *as) {
return as->code_base;
}
/*
STATIC void asm_thumb_write_byte_1(asm_thumb_t *as, byte b1) {
byte *c = asm_thumb_get_cur_to_write_bytes(as, 1);
c[0] = b1;
}
*/
/*
#define IMM32_L0(x) ((x) & 0xff)
#define IMM32_L1(x) (((x) >> 8) & 0xff)
#define IMM32_L2(x) (((x) >> 16) & 0xff)
#define IMM32_L3(x) (((x) >> 24) & 0xff)
STATIC void asm_thumb_write_word32(asm_thumb_t *as, int w32) {
byte *c = asm_thumb_get_cur_to_write_bytes(as, 4);
c[0] = IMM32_L0(w32);
c[1] = IMM32_L1(w32);
c[2] = IMM32_L2(w32);
c[3] = IMM32_L3(w32);
}
*/
// rlolist is a bit map indicating desired lo-registers
#define OP_PUSH_RLIST(rlolist) (0xb400 | (rlolist))
#define OP_PUSH_RLIST_LR(rlolist) (0xb400 | 0x0100 | (rlolist))
#define OP_POP_RLIST(rlolist) (0xbc00 | (rlolist))
#define OP_POP_RLIST_PC(rlolist) (0xbc00 | 0x0100 | (rlolist))
#define OP_ADD_SP(num_words) (0xb000 | (num_words))
#define OP_SUB_SP(num_words) (0xb080 | (num_words))
// locals:
// - stored on the stack in ascending order
// - numbered 0 through num_locals-1
// - SP points to first local
//
// | SP
// v
// l0 l1 l2 ... l(n-1)
// ^ ^
// | low address | high address in RAM
void asm_thumb_entry(asm_thumb_t *as, int num_locals) {
// work out what to push and how many extra spaces to reserve on stack
// so that we have enough for all locals and it's aligned an 8-byte boundary
// we push extra regs (r1, r2, r3) to help do the stack adjustment
// we probably should just always subtract from sp, since this would be more efficient
// for push rlist, lowest numbered register at the lowest address
uint reglist;
uint stack_adjust;
if (num_locals < 0) {
num_locals = 0;
}
// don't pop r0 because it's used for return value
switch (num_locals) {
case 0:
reglist = 0xf2;
stack_adjust = 0;
break;
case 1:
reglist = 0xf2;
stack_adjust = 0;
break;
case 2:
reglist = 0xfe;
stack_adjust = 0;
break;
case 3:
reglist = 0xfe;
stack_adjust = 0;
break;
default:
reglist = 0xfe;
stack_adjust = ((num_locals - 3) + 1) & (~1);
break;
}
asm_thumb_op16(as, OP_PUSH_RLIST_LR(reglist));
if (stack_adjust > 0) {
asm_thumb_op16(as, OP_SUB_SP(stack_adjust));
}
as->push_reglist = reglist;
as->stack_adjust = stack_adjust;
}
void asm_thumb_exit(asm_thumb_t *as) {
if (as->stack_adjust > 0) {
asm_thumb_op16(as, OP_ADD_SP(as->stack_adjust));
}
asm_thumb_op16(as, OP_POP_RLIST_PC(as->push_reglist));
}
void asm_thumb_label_assign(asm_thumb_t *as, uint label) {
assert(label < as->max_num_labels);
if (as->pass < ASM_THUMB_PASS_EMIT) {
// assign label offset
assert(as->label_offsets[label] == -1);
as->label_offsets[label] = as->code_offset;
} else {
// ensure label offset has not changed from PASS_COMPUTE to PASS_EMIT
//printf("l%d: (at %d=%ld)\n", label, as->label_offsets[label], as->code_offset);
assert(as->label_offsets[label] == as->code_offset);
}
}
void asm_thumb_align(asm_thumb_t* as, uint align) {
// TODO fill unused data with NOPs?
as->code_offset = (as->code_offset + align - 1) & (~(align - 1));
}
void asm_thumb_data(asm_thumb_t* as, uint bytesize, uint val) {
byte *c = asm_thumb_get_cur_to_write_bytes(as, bytesize);
// only write to the buffer in the emit pass (otherwise we overflow dummy_data)
if (as->pass == ASM_THUMB_PASS_EMIT) {
// little endian
for (uint i = 0; i < bytesize; i++) {
*c++ = val;
val >>= 8;
}
}
}
STATIC mp_uint_t get_label_dest(asm_thumb_t *as, uint label) {
assert(label < as->max_num_labels);
return as->label_offsets[label];
}
void asm_thumb_op16(asm_thumb_t *as, uint op) {
byte *c = asm_thumb_get_cur_to_write_bytes(as, 2);
// little endian
c[0] = op;
c[1] = op >> 8;
}
void asm_thumb_op32(asm_thumb_t *as, uint op1, uint op2) {
byte *c = asm_thumb_get_cur_to_write_bytes(as, 4);
// little endian, op1 then op2
c[0] = op1;
c[1] = op1 >> 8;
c[2] = op2;
c[3] = op2 >> 8;
}
#define OP_FORMAT_4(op, rlo_dest, rlo_src) ((op) | ((rlo_src) << 3) | (rlo_dest))
void asm_thumb_format_4(asm_thumb_t *as, uint op, uint rlo_dest, uint rlo_src) {
assert(rlo_dest < ASM_THUMB_REG_R8);
assert(rlo_src < ASM_THUMB_REG_R8);
asm_thumb_op16(as, OP_FORMAT_4(op, rlo_dest, rlo_src));
}
void asm_thumb_mov_reg_reg(asm_thumb_t *as, uint reg_dest, uint reg_src) {
uint op_lo;
if (reg_src < 8) {
op_lo = reg_src << 3;
} else {
op_lo = 0x40 | ((reg_src - 8) << 3);
}
if (reg_dest < 8) {
op_lo |= reg_dest;
} else {
op_lo |= 0x80 | (reg_dest - 8);
}
// mov reg_dest, reg_src
asm_thumb_op16(as, 0x4600 | op_lo);
}
// if loading lo half with movw, the i16 value will be zero extended into the r32 register!
void asm_thumb_mov_reg_i16(asm_thumb_t *as, uint mov_op, uint reg_dest, int i16_src) {
assert(reg_dest < ASM_THUMB_REG_R15);
// mov[wt] reg_dest, #i16_src
asm_thumb_op32(as, mov_op | ((i16_src >> 1) & 0x0400) | ((i16_src >> 12) & 0xf), ((i16_src << 4) & 0x7000) | (reg_dest << 8) | (i16_src & 0xff));
}
#define OP_B_N(byte_offset) (0xe000 | (((byte_offset) >> 1) & 0x07ff))
bool asm_thumb_b_n_label(asm_thumb_t *as, uint label) {
mp_uint_t dest = get_label_dest(as, label);
mp_int_t rel = dest - as->code_offset;
rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
asm_thumb_op16(as, OP_B_N(rel));
return as->pass != ASM_THUMB_PASS_EMIT || SIGNED_FIT12(rel);
}
#define OP_BCC_N(cond, byte_offset) (0xd000 | ((cond) << 8) | (((byte_offset) >> 1) & 0x00ff))
// all these bit arithmetics need coverage testing!
#define OP_BCC_W_HI(cond, byte_offset) (0xf000 | ((cond) << 6) | (((byte_offset) >> 10) & 0x0400) | (((byte_offset) >> 14) & 0x003f))
#define OP_BCC_W_LO(byte_offset) (0x8000 | ((byte_offset) & 0x2000) | (((byte_offset) >> 1) & 0x0fff))
bool asm_thumb_bcc_nw_label(asm_thumb_t *as, int cond, uint label, bool wide) {
mp_uint_t dest = get_label_dest(as, label);
mp_int_t rel = dest - as->code_offset;
rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
if (!wide) {
asm_thumb_op16(as, OP_BCC_N(cond, rel));
return as->pass != ASM_THUMB_PASS_EMIT || SIGNED_FIT9(rel);
} else {
asm_thumb_op32(as, OP_BCC_W_HI(cond, rel), OP_BCC_W_LO(rel));
return true;
}
}
#define OP_BL_HI(byte_offset) (0xf000 | (((byte_offset) >> 12) & 0x07ff))
#define OP_BL_LO(byte_offset) (0xf800 | (((byte_offset) >> 1) & 0x07ff))
bool asm_thumb_bl_label(asm_thumb_t *as, uint label) {
mp_uint_t dest = get_label_dest(as, label);
mp_int_t rel = dest - as->code_offset;
rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
asm_thumb_op32(as, OP_BL_HI(rel), OP_BL_LO(rel));
return as->pass != ASM_THUMB_PASS_EMIT || SIGNED_FIT23(rel);
}
void asm_thumb_mov_reg_i32(asm_thumb_t *as, uint reg_dest, mp_uint_t i32) {
// movw, movt does it in 8 bytes
// ldr [pc, #], dw does it in 6 bytes, but we might not reach to end of code for dw
asm_thumb_mov_reg_i16(as, ASM_THUMB_OP_MOVW, reg_dest, i32);
asm_thumb_mov_reg_i16(as, ASM_THUMB_OP_MOVT, reg_dest, i32 >> 16);
}
void asm_thumb_mov_reg_i32_optimised(asm_thumb_t *as, uint reg_dest, int i32) {
if (reg_dest < 8 && UNSIGNED_FIT8(i32)) {
asm_thumb_mov_rlo_i8(as, reg_dest, i32);
} else if (UNSIGNED_FIT16(i32)) {
asm_thumb_mov_reg_i16(as, ASM_THUMB_OP_MOVW, reg_dest, i32);
} else {
asm_thumb_mov_reg_i32(as, reg_dest, i32);
}
}
// i32 is stored as a full word in the code, and aligned to machine-word boundary
// TODO this is very inefficient, improve it!
void asm_thumb_mov_reg_i32_aligned(asm_thumb_t *as, uint reg_dest, int i32) {
// align on machine-word + 2
if ((as->code_offset & 3) == 0) {
asm_thumb_op16(as, ASM_THUMB_OP_NOP);
}
// jump over the i32 value (instruction prefetch adds 2 to PC)
asm_thumb_op16(as, OP_B_N(2));
// store i32 on machine-word aligned boundary
asm_thumb_data(as, 4, i32);
// do the actual load of the i32 value
asm_thumb_mov_reg_i32_optimised(as, reg_dest, i32);
}
#define OP_STR_TO_SP_OFFSET(rlo_dest, word_offset) (0x9000 | ((rlo_dest) << 8) | ((word_offset) & 0x00ff))
#define OP_LDR_FROM_SP_OFFSET(rlo_dest, word_offset) (0x9800 | ((rlo_dest) << 8) | ((word_offset) & 0x00ff))
void asm_thumb_mov_local_reg(asm_thumb_t *as, int local_num, uint rlo_src) {
assert(rlo_src < ASM_THUMB_REG_R8);
int word_offset = local_num;
assert(as->pass < ASM_THUMB_PASS_EMIT || word_offset >= 0);
asm_thumb_op16(as, OP_STR_TO_SP_OFFSET(rlo_src, word_offset));
}
void asm_thumb_mov_reg_local(asm_thumb_t *as, uint rlo_dest, int local_num) {
assert(rlo_dest < ASM_THUMB_REG_R8);
int word_offset = local_num;
assert(as->pass < ASM_THUMB_PASS_EMIT || word_offset >= 0);
asm_thumb_op16(as, OP_LDR_FROM_SP_OFFSET(rlo_dest, word_offset));
}
#define OP_ADD_REG_SP_OFFSET(rlo_dest, word_offset) (0xa800 | ((rlo_dest) << 8) | ((word_offset) & 0x00ff))
void asm_thumb_mov_reg_local_addr(asm_thumb_t *as, uint rlo_dest, int local_num) {
assert(rlo_dest < ASM_THUMB_REG_R8);
int word_offset = local_num;
assert(as->pass < ASM_THUMB_PASS_EMIT || word_offset >= 0);
asm_thumb_op16(as, OP_ADD_REG_SP_OFFSET(rlo_dest, word_offset));
}
// this could be wrong, because it should have a range of +/- 16MiB...
#define OP_BW_HI(byte_offset) (0xf000 | (((byte_offset) >> 12) & 0x07ff))
#define OP_BW_LO(byte_offset) (0xb800 | (((byte_offset) >> 1) & 0x07ff))
void asm_thumb_b_label(asm_thumb_t *as, uint label) {
mp_uint_t dest = get_label_dest(as, label);
mp_int_t rel = dest - as->code_offset;
rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
if (dest != -1 && rel <= -4) {
// is a backwards jump, so we know the size of the jump on the first pass
// calculate rel assuming 12 bit relative jump
if (SIGNED_FIT12(rel)) {
asm_thumb_op16(as, OP_B_N(rel));
} else {
goto large_jump;
}
} else {
// is a forwards jump, so need to assume it's large
large_jump:
asm_thumb_op32(as, OP_BW_HI(rel), OP_BW_LO(rel));
}
}
void asm_thumb_bcc_label(asm_thumb_t *as, int cond, uint label) {
mp_uint_t dest = get_label_dest(as, label);
mp_int_t rel = dest - as->code_offset;
rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
if (dest != -1 && rel <= -4) {
// is a backwards jump, so we know the size of the jump on the first pass
// calculate rel assuming 9 bit relative jump
if (SIGNED_FIT9(rel)) {
asm_thumb_op16(as, OP_BCC_N(cond, rel));
} else {
goto large_jump;
}
} else {
// is a forwards jump, so need to assume it's large
large_jump:
asm_thumb_op32(as, OP_BCC_W_HI(cond, rel), OP_BCC_W_LO(rel));
}
}
#define OP_BLX(reg) (0x4780 | ((reg) << 3))
#define OP_SVC(arg) (0xdf00 | (arg))
void asm_thumb_bl_ind(asm_thumb_t *as, void *fun_ptr, uint fun_id, uint reg_temp) {
/* TODO make this use less bytes
uint rlo_base = ASM_THUMB_REG_R3;
uint rlo_dest = ASM_THUMB_REG_R7;
uint word_offset = 4;
asm_thumb_op16(as, 0x0000);
asm_thumb_op16(as, 0x6800 | (word_offset << 6) | (rlo_base << 3) | rlo_dest); // ldr rlo_dest, [rlo_base, #offset]
asm_thumb_op16(as, 0x4780 | (ASM_THUMB_REG_R9 << 3)); // blx reg
*/
if (fun_id < 32) {
// load ptr to function from table, indexed by fun_id (must be in range 0-31); 4 bytes
asm_thumb_op16(as, ASM_THUMB_FORMAT_9_10_ENCODE(ASM_THUMB_FORMAT_9_LDR | ASM_THUMB_FORMAT_9_WORD_TRANSFER, reg_temp, ASM_THUMB_REG_R7, fun_id));
asm_thumb_op16(as, OP_BLX(reg_temp));
} else {
// load ptr to function into register using immediate; 6 bytes
asm_thumb_mov_reg_i32(as, reg_temp, (mp_uint_t)fun_ptr);
asm_thumb_op16(as, OP_BLX(reg_temp));
}
}
#endif // MICROPY_EMIT_THUMB || MICROPY_EMIT_INLINE_THUMB
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