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py/asmxtensa: Handle function entry/exit when stack use larger than 127.

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This commit is contained in:
Damien George 2018-08-16 13:43:36 +10:00
parent 8c49995398
commit f7d6108d1a
1 changed files with 13 additions and 2 deletions
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15
py/asmxtensa.c
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@ -69,7 +69,12 @@ void asm_xtensa_entry(asm_xtensa_t *as, int num_locals) {
// adjust the stack-pointer to store a0, a12, a13, a14 and locals, 16-byte aligned
as->stack_adjust = (((4 + num_locals) * WORD_SIZE) + 15) & ~15;
asm_xtensa_op_addi(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, -as->stack_adjust);
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)
asm_xtensa_op_s32i_n(as, ASM_XTENSA_REG_A0, ASM_XTENSA_REG_A1, 0);
@ -86,7 +91,13 @@ void asm_xtensa_exit(asm_xtensa_t *as) {
asm_xtensa_op_l32i_n(as, ASM_XTENSA_REG_A0, ASM_XTENSA_REG_A1, 0);
// restore stack-pointer and return
asm_xtensa_op_addi(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, as->stack_adjust);
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(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A9);
}
asm_xtensa_op_ret_n(as);
}