fix some minor issue

.gitignore

@@ -27,6 +27,7 @@ __pycache__
 
 test/*
 !test/test_src
+!test/longer-cases
 !test/script.gdb
 !test/build_*
 !test/run_*

src/riscv/before_alloc.mbt

@@ -13,7 +13,7 @@ fn reserve_swap_reg(cfg : @ssacfg.SsaCfg, block : @ssacfg.Block) -> Unit {
     match inst {
       Prim(bind, Math(_) | Eq | Le as op, [lhs, rhs]) as inst =>
         if is_imm(lhs) && is_imm(rhs) {
-          let tmp = cfg.new_named("tmp_swap", ty=Double)
+          let tmp = cfg.new_named("tmp_swap", ty=lhs.get_type())
           insts.push(@ssacfg.Inst::Copy(tmp, lhs))
           insts.push(Prim(bind, op, [Var(tmp), rhs]))
         } else {

src/riscv/extern_stub.mbt

@@ -121,6 +121,9 @@ fn generate_stub(cfg : @ssacfg.SsaCfg) -> AssemblyFunction {
     body.append(
       [
         Label(stub_resolved),
+        Comment("Round down the stack for alignment, giving up the space"),
+        Li(T5, "-16"),
+        And(Sp, Sp, T5),
         Comment("Call the external function"),
         Jalr(T6),
         Comment("Put continuation at \{kont_reg}"),