From 3929d9038f3da75dbba8678cc8f2ba703b83b331 Mon Sep 17 00:00:00 2001
From: Johannes Stoelp <johannes.stoelp@gmail.com>
Date: Wed, 28 Feb 2024 19:22:57 +0100
Subject: tiny_vm: remove additional cache lookup after translating a new bb
---
examples/tiny_vm.rs | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)
(limited to 'examples')
diff --git a/examples/tiny_vm.rs b/examples/tiny_vm.rs
index b441a4a..86f5eaf 100644
--- a/examples/tiny_vm.rs
+++ b/examples/tiny_vm.rs
@@ -237,22 +237,27 @@ impl TinyVm {
/// _basic blocks_ on demand.
pub fn jit(&mut self) {
'outer: loop {
- if let Some(bb_fn) = self.jit_cache[self.pc] {
- match bb_fn(self.regs.as_mut_ptr(), self.dmem.as_mut_ptr()) {
- JitRet(0, insn) => {
- self.pc += insn as usize;
- self.icnt += insn as usize;
- break 'outer;
- }
- JitRet(insn, reenter_pc) => {
- self.pc = reenter_pc as usize;
- self.icnt += insn as usize;
- }
- }
+ let bb_fn = if let Some(bb_fn) = self.jit_cache[self.pc] {
+ bb_fn
} else {
let bb_fn = self.translate_next_bb();
self.jit_cache[self.pc] = Some(bb_fn);
//println!("[0x{:02x}] translated bb at {:p}", self.pc, bb_fn);
+ bb_fn
+ };
+
+ match bb_fn(self.regs.as_mut_ptr(), self.dmem.as_mut_ptr()) {
+ // HALT instruction hit.
+ JitRet(0, insn) => {
+ self.pc += insn as usize;
+ self.icnt += insn as usize;
+ break 'outer;
+ }
+ // End of basic block, re-enter.
+ JitRet(insn, reenter_pc) => {
+ self.pc = reenter_pc as usize;
+ self.icnt += insn as usize;
+ }
}
}
}
--
cgit v1.2.3