diff options
Diffstat (limited to 'examples/tiny_vm.rs')
| -rw-r--r-- | examples/tiny_vm.rs | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/examples/tiny_vm.rs b/examples/tiny_vm.rs index 86f5eaf..1f4c653 100644 --- a/examples/tiny_vm.rs +++ b/examples/tiny_vm.rs @@ -38,7 +38,7 @@ use juicebox_asm::insn::*; use juicebox_asm::Runtime; -use juicebox_asm::{Asm, Imm16, Imm64, Label, MemOp, Reg16, Reg64}; +use juicebox_asm::{Asm, Imm16, Imm64, MemOp, Reg16, Reg64}; /// A guest physical address. pub struct PhysAddr(pub u16); @@ -330,13 +330,13 @@ impl TinyVm { TinyInsn::BranchZero(a, disp) => { bb.cmp(reg_op(a), Imm16::from(0u16)); bb.mov(Reg64::rax, Imm64::from(bb_icnt())); - bb.mov(Reg64::rdx, Imm64::from(reenter_pc(disp))); - - let mut skip_next_pc = Label::new(); - // If register is zero, skip setting next pc as reenter pc. - bb.jz(&mut skip_next_pc); + // Default fall-through PC (branch not taken). bb.mov(Reg64::rdx, Imm64::from(reenter_pc(pc))); - bb.bind(&mut skip_next_pc); + + // Conditionally update PC if condition is ZERO (branch taken). + bb.mov(Reg64::r11, Imm64::from(reenter_pc(disp))); + bb.cmovz(Reg64::rdx, Reg64::r11); + bb.ret(); break 'outer; } |