diff options
| -rw-r--r-- | risc-v/riscv.sail | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/risc-v/riscv.sail b/risc-v/riscv.sail index 8658ae96..f36dba57 100644 --- a/risc-v/riscv.sail +++ b/risc-v/riscv.sail @@ -24,11 +24,12 @@ union ast member ((bit[21]), regno) JAL function clause decode ((bit[20]) imm : (regno) rd : 0b1101111) = Some (JAL(imm[19] : imm[7..0] : imm[8] : imm[18..13] : imm[12..9] : 0b0, rd)) -function clause execute (JAL(imm, rd)) = - let (bit[64]) offset = EXTS(imm) in { - nextPC := PC + offset; - wGPR(rd, PC + 4); - } +function clause execute (JAL(imm, rd)) = { + (bit[64]) pc := PC; + wGPR(rd, pc + 4); + (bit[64]) offset := EXTS(imm); + nextPC := pc + offset; +} (********************************************************************) union ast member((bit[12]), regno, regno) JALR @@ -36,11 +37,12 @@ union ast member((bit[12]), regno, regno) JALR function clause decode ((bit[12]) imm : (regno) rs1 : 0b000 : (regno) rd : 0b1100111) = Some(JALR(imm, rs1, rd)) -function clause execute (JALR(imm, rs1, rd)) = - let (bit[64]) newPC = rGPR(rs1) + EXTS(imm) in { - nextPC := newPC[63..1] : 0b0; - wGPR(rd, PC + 4); - } +function clause execute (JALR(imm, rs1, rd)) = { + (* write rd before anything else to prevent unintended strength *) + wGPR(rd, PC + 4); + (bit[64]) newPC := rGPR(rs1) + EXTS(imm); + nextPC := newPC[63..1] : 0b0; +} (********************************************************************) union ast member ((bit[13]), regno, regno, bop) BTYPE |