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Fix off by one issues in register implementations

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word register 0 refers to the first 8 bytes of the dynamic array.
Hence the used counter should be at least 8 bytes.  This deals with
those issues.  Also print more useful information in
vm_print_registers (how many byte|hword|word registers are currently
in use, how many are available).
This commit is contained in:
Aryadev Chavali
2023-11-01 18:31:11 +00:00
parent dab1729f61
commit cb8b3f3b8c
1 changed files with 11 additions and 6 deletions
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17
vm/runtime.c
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@@ -336,10 +336,15 @@ void vm_stop(vm_t *vm)
void vm_print_registers(vm_t *vm, FILE *fp) void vm_print_registers(vm_t *vm, FILE *fp)
{ {
registers_t reg = vm->registers; registers_t reg = vm->registers;
fprintf(fp, "Registers.used = %luB\nRegisters.available = %luB\n", fprintf(
vm->registers.used, vm->registers.available); fp,
"Registers.used = %luB/%luH/%luW\nRegisters.available = %luB/%luH/%luW\n",
vm->registers.used, vm->registers.used / HWORD_SIZE,
vm->registers.used / WORD_SIZE, vm->registers.available,
vm->registers.available / HWORD_SIZE,
vm->registers.available / WORD_SIZE);
fprintf(fp, "Registers.reg = ["); fprintf(fp, "Registers.reg = [");
for (size_t i = 0; i <= (reg.used / WORD_SIZE); ++i) for (size_t i = 0; i < (reg.used / WORD_SIZE); ++i)
{ {
fprintf(fp, "{%lu:%lX}", i, VM_NTH_REGISTER(reg, i)); fprintf(fp, "{%lu:%lX}", i, VM_NTH_REGISTER(reg, i));
if (i != reg.used - 1) if (i != reg.used - 1)
@@ -518,7 +523,7 @@ err_t vm_mov_hword(vm_t *vm, word reg)
const size_t diff = (hwords + 1) * HWORD_SIZE; const size_t diff = (hwords + 1) * HWORD_SIZE;
darr_ensure_capacity(&vm->registers, diff); darr_ensure_capacity(&vm->registers, diff);
vm->registers.used = MAX(vm->registers.used, (reg * HWORD_SIZE) + 1); vm->registers.used = MAX(vm->registers.used, (reg + 1) * HWORD_SIZE);
} }
data_t ret = {0}; data_t ret = {0};
err_t err = vm_pop_hword(vm, &ret); err_t err = vm_pop_hword(vm, &ret);
@@ -540,7 +545,7 @@ err_t vm_mov_word(vm_t *vm, word reg)
const size_t diff = (words + 1) * WORD_SIZE; const size_t diff = (words + 1) * WORD_SIZE;
darr_ensure_capacity(&vm->registers, diff); darr_ensure_capacity(&vm->registers, diff);
vm->registers.used = MAX(vm->registers.used, (reg * WORD_SIZE) + 1); vm->registers.used = MAX(vm->registers.used, (reg + 1) * WORD_SIZE);
} }
else if (vm->stack.ptr < sizeof(word)) else if (vm->stack.ptr < sizeof(word))
return ERR_STACK_UNDERFLOW; return ERR_STACK_UNDERFLOW;
@@ -548,7 +553,7 @@ err_t vm_mov_word(vm_t *vm, word reg)
err_t err = vm_pop_word(vm, &ret); err_t err = vm_pop_word(vm, &ret);
if (err) if (err)
return err; return err;
VM_NTH_REGISTER(vm->registers, reg) = ret.as_word; ((word *)(vm->registers.data))[reg] = ret.as_word;
return ERR_OK; return ERR_OK;
} }