From 24f8673dce3f8ac8658681f16d856c45dded377a Mon Sep 17 00:00:00 2001 From: David Li Date: Sun, 20 Dec 2015 15:02:13 -0500 Subject: Set LSB of target to 0 in JALR --- src/simulator.rs | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/src/simulator.rs b/src/simulator.rs index 607a3b5..bf39c5e 100644 --- a/src/simulator.rs +++ b/src/simulator.rs @@ -14,6 +14,7 @@ struct RegisterFile { #[derive(Clone)] struct Core { + // TODO: directly encode PC as u32, as architecturally specified pc: usize, registers: RegisterFile, running: bool, @@ -106,15 +107,17 @@ impl Simulator { core.running = false; } else { - let target = ((pc as i32) + inst.i_imm()) as usize; + let target = (((pc as i32) + inst.i_imm()) & 0xFFFFFFFE) as usize; core.registers.write_word(inst.rd(), pc + 4); core.pc = target; + return; } }, isa::opcodes::JAL => { let target = ((pc as i32) + inst.uj_imm()) as usize; core.registers.write_word(inst.rd(), pc + 4); core.pc = target; + return; } isa::opcodes::BRANCH => { -- cgit v1.2.3