diff options
| author | Mason Reed <mason@vector35.com> | 2024-11-30 19:00:49 -0500 |
|---|---|---|
| committer | Mason Reed <mason@vector35.com> | 2024-11-30 19:01:57 -0500 |
| commit | b92dac445e18fc2cf70b3cc5da26b996efa78a1f (patch) | |
| tree | 7e44b801156799e185af6008d42c3c26051e6bb9 /arch | |
| parent | bf076bf469a73c88c68e6e8d1d848ae8860ebe90 (diff) | |
Remove temp register in JALR RISC-V when unused
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv/src/lib.rs | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/riscv/src/lib.rs b/arch/riscv/src/lib.rs index 76e94cc2..97998239 100644 --- a/arch/riscv/src/lib.rs +++ b/arch/riscv/src/lib.rs @@ -1241,9 +1241,20 @@ impl<D: 'static + RiscVDisassembler + Send + Sync> architecture::Architecture fo (0, 1, 0) => il.ret(target).append(), // jalr zero, ra, 0 (1, _, _) => il.call(target).append(), // indirect call (0, _, _) => il.jump(target).append(), // indirect jump - (_, _, _) => { + (rd_id, rs1_id, _) if rd_id == rs1_id => { // store the target in a temporary register so we don't clobber it when rd == rs1 - il.set_reg(max_width, llil::Register::Temp(0), target).append(); + let tmp_reg: llil::Register<Register<D>> = llil::Register::Temp(0); + il.set_reg(max_width, tmp_reg, target).append(); + // indirect jump with storage of next address to non-`ra` register + il.set_reg( + max_width, + Register::from(rd), + il.const_ptr(addr.wrapping_add(inst_len)), + ) + .append(); + il.jump(tmp_reg).append(); + } + (_, _, _) => { // indirect jump with storage of next address to non-`ra` register il.set_reg( max_width, @@ -1251,7 +1262,7 @@ impl<D: 'static + RiscVDisassembler + Send + Sync> architecture::Architecture fo il.const_ptr(addr.wrapping_add(inst_len)), ) .append(); - il.jump(il.reg(max_width, llil::Register::Temp(0))).append(); + il.jump(target).append(); } } } |