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// See LICENSE for license details.
#include "processor.h"
#include "mmu.h"
#include "sim.h"
#include <cassert>
static void commit_log_stash_privilege(state_t* state)
{
#ifdef RISCV_ENABLE_COMMITLOG
state->last_inst_priv = state->prv;
#endif
}
static void commit_log_print_insn(state_t* state, reg_t pc, insn_t insn)
{
#ifdef RISCV_ENABLE_COMMITLOG
int32_t priv = state->last_inst_priv;
uint64_t mask = (insn.length() == 8 ? uint64_t(0) : (uint64_t(1) << (insn.length() * 8))) - 1;
if (state->log_reg_write.addr) {
fprintf(stderr, "%1d 0x%016" PRIx64 " (0x%08" PRIx64 ") %c%2" PRIu64 " 0x%016" PRIx64 "\n",
priv,
pc,
insn.bits() & mask,
state->log_reg_write.addr & 1 ? 'f' : 'x',
state->log_reg_write.addr >> 1,
state->log_reg_write.data);
} else {
fprintf(stderr, "%1d 0x%016" PRIx64 " (0x%08" PRIx64 ")\n", priv, pc, insn.bits() & mask);
}
state->log_reg_write.addr = 0;
#endif
}
inline void processor_t::update_histogram(reg_t pc)
{
#ifdef RISCV_ENABLE_HISTOGRAM
pc_histogram[pc]++;
#endif
}
static reg_t execute_insn(processor_t* p, reg_t pc, insn_fetch_t fetch)
{
commit_log_stash_privilege(p->get_state());
reg_t npc = fetch.func(p, fetch.insn, pc);
if (!invalid_pc(npc)) {
commit_log_print_insn(p->get_state(), pc, fetch.insn);
p->update_histogram(pc);
}
return npc;
}
// fetch/decode/execute loop
void processor_t::step(size_t n)
{
// TODO: get_interrupt() isn't super fast. Does that matter?
if (state.dcsr.cause == DCSR_CAUSE_NONE &&
sim->debug_module.get_interrupt(id)) {
enter_debug_mode(DCSR_CAUSE_DEBUGINT);
}
if (state.dcsr.cause != DCSR_CAUSE_NONE) {
// In Debug Mode, just do 11 steps at a time. Otherwise we're going to be
// spinning the rest of the time anyway.
n = std::min(n, (size_t) 11);
}
if (debug) {
fprintf(stderr, "step(%ld)\n", n);
}
while (n > 0) {
size_t instret = 0;
reg_t pc = state.pc;
mmu_t* _mmu = mmu;
#define advance_pc() \
if (unlikely(invalid_pc(pc))) { \
switch (pc) { \
case PC_SERIALIZE_BEFORE: state.serialized = true; break; \
case PC_SERIALIZE_AFTER: instret++; break; \
default: abort(); \
} \
pc = state.pc; \
break; \
} else { \
state.pc = pc; \
instret++; \
}
try
{
take_interrupt();
// When we might single step, use the slow loop instead of the fast one.
if (unlikely(debug || state.single_step != state.STEP_NONE || state.dcsr.cause))
{
while (instret < n)
{
// TODO: implement this for the main loop also. To keep
// performance good, probably go into this version when entering
// debug mode or something.
if (unlikely(state.single_step == state.STEP_STEPPING)) {
state.single_step = state.STEP_STEPPED;
} else if (unlikely(state.single_step == state.STEP_STEPPED)) {
state.single_step = state.STEP_NONE;
enter_debug_mode(DCSR_CAUSE_STEP);
// enter_debug_mode changed state.pc, so we can't just continue.
break;
}
insn_fetch_t fetch = mmu->load_insn(pc);
if (debug && !state.serialized)
disasm(fetch.insn);
pc = execute_insn(this, pc, fetch);
advance_pc();
}
}
else while (instret < n)
{
size_t idx = _mmu->icache_index(pc);
auto ic_entry = _mmu->access_icache(pc);
#define ICACHE_ACCESS(i) { \
insn_fetch_t fetch = ic_entry->data; \
ic_entry++; \
pc = execute_insn(this, pc, fetch); \
if (i == mmu_t::ICACHE_ENTRIES-1) break; \
if (unlikely(ic_entry->tag != pc)) goto miss; \
if (unlikely(instret+1 == n)) break; \
instret++; \
state.pc = pc; \
}
switch (idx) {
#include "icache.h"
}
advance_pc();
continue;
miss:
advance_pc();
// refill I$ if it looks like there wasn't a taken branch
if (pc > (ic_entry-1)->tag && pc <= (ic_entry-1)->tag + MAX_INSN_LENGTH)
_mmu->refill_icache(pc, ic_entry);
}
}
catch(trap_t& t)
{
take_trap(t, pc);
n = instret;
}
state.minstret += instret;
n -= instret;
}
}
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