/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 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 "py/mpconfig.h"
// wrapper around everything in this file
#if MICROPY_EMIT_XTENSA || MICROPY_EMIT_INLINE_XTENSA
#include "py/asmxtensa.h"
#define WORD_SIZE (4)
#define SIGNED_FIT8(x) ((((x) & 0xffffff80) == 0) || (((x) & 0xffffff80) == 0xffffff80))
#define SIGNED_FIT12(x) ((((x) & 0xfffff800) == 0) || (((x) & 0xfffff800) == 0xfffff800))
#define NUM_REGS_SAVED (5)
void asm_xtensa_end_pass(asm_xtensa_t *as) {
as->num_const = as->cur_const;
as->cur_const = 0;
#if 0
// make a hex dump of the machine code
if (as->base.pass == MP_ASM_PASS_EMIT) {
uint8_t *d = as->base.code_base;
printf("XTENSA ASM:");
for (int i = 0; i < ((as->base.code_size + 15) & ~15); ++i) {
if (i % 16 == 0) {
printf("\n%08x:", (uint32_t)&d[i]);
}
if (i % 2 == 0) {
printf(" ");
}
printf("%02x", d[i]);
}
printf("\n");
}
#endif
}
void asm_xtensa_entry(asm_xtensa_t *as, int num_locals) {
// jump over the constants
asm_xtensa_op_j(as, as->num_const * WORD_SIZE + 4 - 4);
mp_asm_base_get_cur_to_write_bytes(&as->base, 1); // padding/alignment byte
as->const_table = (uint32_t*)mp_asm_base_get_cur_to_write_bytes(&as->base, as->num_const * 4);
// adjust the stack-pointer to store a0, a12, a13, a14, a15 and locals, 16-byte aligned
as->stack_adjust = (((NUM_REGS_SAVED + num_locals) * WORD_SIZE) + 15) & ~15;
if (SIGNED_FIT8(-as->stack_adjust)) {
asm_xtensa_op_addi(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, -as->stack_adjust);
} else {
asm_xtensa_op_movi(as, ASM_XTENSA_REG_A9, as->stack_adjust);
asm_xtensa_op_sub(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A9);
}
// save return value (a0) and callee-save registers (a12, a13, a14, a15)
asm_xtensa_op_s32i_n(as, ASM_XTENSA_REG_A0, ASM_XTENSA_REG_A1, 0);
for (int i = 1; i < NUM_REGS_SAVED; ++i) {
asm_xtensa_op_s32i_n(as, ASM_XTENSA_REG_A11 + i, ASM_XTENSA_REG_A1, i);
}
}
void asm_xtensa_exit(asm_xtensa_t *as) {
// restore registers
for (int i = NUM_REGS_SAVED - 1; i >= 1; --i) {
asm_xtensa_op_l32i_n(as, ASM_XTENSA_REG_A11 + i, ASM_XTENSA_REG_A1, i);
}
asm_xtensa_op_l32i_n(as, ASM_XTENSA_REG_A0, ASM_XTENSA_REG_A1, 0);
// restore stack-pointer and return
if (SIGNED_FIT8(as->stack_adjust)) {
asm_xtensa_op_addi(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, as->stack_adjust);
} else {
asm_xtensa_op_movi(as, ASM_XTENSA_REG_A9, as->stack_adjust);
asm_xtensa_op_add_n(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A9);
}
asm_xtensa_op_ret_n(as);
}
STATIC uint32_t get_label_dest(asm_xtensa_t *as, uint label) {
assert(label < as->base.max_num_labels);
return as->base.label_offsets[label];
}
void asm_xtensa_op16(asm_xtensa_t *as, uint16_t op) {
uint8_t *c = mp_asm_base_get_cur_to_write_bytes(&as->base, 2);
if (c != NULL) {
c[0] = op;
c[1] = op >> 8;
}
}
void asm_xtensa_op24(asm_xtensa_t *as, uint32_t op) {
uint8_t *c = mp_asm_base_get_cur_to_write_bytes(&as->base, 3);
if (c != NULL) {
c[0] = op;
c[1] = op >> 8;
c[2] = op >> 16;
}
}
void asm_xtensa_j_label(asm_xtensa_t *as, uint label) {
uint32_t dest = get_label_dest(as, label);
int32_t rel = dest - as->base.code_offset - 4;
// we assume rel, as a signed int, fits in 18-bits
asm_xtensa_op_j(as, rel);
}
void asm_xtensa_bccz_reg_label(asm_xtensa_t *as, uint cond, uint reg, uint label) {
uint32_t dest = get_label_dest(as, label);
int32_t rel = dest - as->base.code_offset - 4;
if (as->base.pass == MP_ASM_PASS_EMIT && !SIGNED_FIT12(rel)) {
printf("ERROR: xtensa bccz out of range\n");
}
asm_xtensa_op_bccz(as, cond, reg, rel);
}
void asm_xtensa_bcc_reg_reg_label(asm_xtensa_t *as, uint cond, uint reg1, uint reg2, uint label) {
uint32_t dest = get_label_dest(as, label);
int32_t rel = dest - as->base.code_offset - 4;
if (as->base.pass == MP_ASM_PASS_EMIT && !SIGNED_FIT8(rel)) {
printf("ERROR: xtensa bcc out of range\n");
}
asm_xtensa_op_bcc(as, cond, reg1, reg2, rel);
}
// convenience function; reg_dest must be different from reg_src[12]
void asm_xtensa_setcc_reg_reg_reg(asm_xtensa_t *as, uint cond, uint reg_dest, uint reg_src1, uint reg_src2) {
asm_xtensa_op_movi_n(as, reg_dest, 1);
asm_xtensa_op_bcc(as, cond, reg_src1, reg_src2, 1);
asm_xtensa_op_movi_n(as, reg_dest, 0);
}
size_t asm_xtensa_mov_reg_i32(asm_xtensa_t *as, uint reg_dest, uint32_t i32) {
// load the constant
uint32_t const_table_offset = (uint8_t*)as->const_table - as->base.code_base;
size_t loc = const_table_offset + as->cur_const * WORD_SIZE;
asm_xtensa_op_l32r(as, reg_dest, as->base.code_offset, loc);
// store the constant in the table
if (as->const_table != NULL) {
as->const_table[as->cur_const] = i32;
}
++as->cur_const;
return loc;
}
void asm_xtensa_mov_reg_i32_optimised(asm_xtensa_t *as, uint reg_dest, uint32_t i32) {
if (SIGNED_FIT12(i32)) {
asm_xtensa_op_movi(as, reg_dest, i32);
} else {
asm_xtensa_mov_reg_i32(as, reg_dest, i32);
}
}
void asm_xtensa_mov_local_reg(asm_xtensa_t *as, int local_num, uint reg_src) {
asm_xtensa_op_s32i(as, reg_src, ASM_XTENSA_REG_A1, NUM_REGS_SAVED + local_num);
}
void asm_xtensa_mov_reg_local(asm_xtensa_t *as, uint reg_dest, int local_num) {
asm_xtensa_op_l32i(as, reg_dest, ASM_XTENSA_REG_A1, NUM_REGS_SAVED + local_num);
}
void asm_xtensa_mov_reg_local_addr(asm_xtensa_t *as, uint reg_dest, int local_num) {
uint off = (NUM_REGS_SAVED + local_num) * WORD_SIZE;
if (SIGNED_FIT8(off)) {
asm_xtensa_op_addi(as, reg_dest, ASM_XTENSA_REG_A1, off);
} else {
asm_xtensa_op_movi(as, reg_dest, off);
asm_xtensa_op_add_n(as, reg_dest, reg_dest, ASM_XTENSA_REG_A1);
}
}
void asm_xtensa_mov_reg_pcrel(asm_xtensa_t *as, uint reg_dest, uint label) {
// Get relative offset from PC
uint32_t dest = get_label_dest(as, label);
int32_t rel = dest - as->base.code_offset;
rel -= 3 + 3; // account for 3 bytes of movi instruction, 3 bytes call0 adjustment
asm_xtensa_op_movi(as, reg_dest, rel); // imm has 12-bit range
// Use call0 to get PC+3 into a0
// call0 destination must be aligned on 4 bytes:
// - code_offset&3=0: off=0, pad=1
// - code_offset&3=1: off=0, pad=0
// - code_offset&3=2: off=1, pad=3
// - code_offset&3=3: off=1, pad=2
uint32_t off = as->base.code_offset >> 1 & 1;
uint32_t pad = (5 - as->base.code_offset) & 3;
asm_xtensa_op_call0(as, off);
mp_asm_base_get_cur_to_write_bytes(&as->base, pad);
// Add PC to relative offset
asm_xtensa_op_add_n(as, reg_dest, reg_dest, ASM_XTENSA_REG_A0);
}
void asm_xtensa_call_ind(asm_xtensa_t *as, uint idx) {
if (idx < 16) {
asm_xtensa_op_l32i_n(as, ASM_XTENSA_REG_A0, ASM_XTENSA_REG_FUN_TABLE, idx);
} else {
asm_xtensa_op_l32i(as, ASM_XTENSA_REG_A0, ASM_XTENSA_REG_FUN_TABLE, idx);
}
asm_xtensa_op_callx0(as, ASM_XTENSA_REG_A0);
}
#endif // MICROPY_EMIT_XTENSA || MICROPY_EMIT_INLINE_XTENSA