diff --git a/lang/src/son.rs b/lang/src/son.rs
index 2e4e262..9208ed0 100644
--- a/lang/src/son.rs
+++ b/lang/src/son.rs
@@ -2066,6 +2066,11 @@ impl Node {
     fn is_data_phi(&self) -> bool {
         self.kind == Kind::Phi && self.ty != ty::Id::VOID
     }
+
+    fn has_no_value(&self) -> bool {
+        (self.kind.is_cfg() && (!self.kind.is_call() || self.ty == ty::Id::VOID))
+            || matches!(self.kind, Kind::Stre)
+    }
 }
 
 type LoopDepth = u16;
diff --git a/lang/src/son/hbvm/regalloc.rs b/lang/src/son/hbvm/regalloc.rs
index 7e7c253..832a6ab 100644
--- a/lang/src/son/hbvm/regalloc.rs
+++ b/lang/src/son/hbvm/regalloc.rs
@@ -75,7 +75,7 @@ impl HbvmBackend {
                 PLoc::WideReg(rg, size) => (rg, size),
                 PLoc::Reg(rg, size) if ty.loc(tys) == Loc::Stack => (rg, size),
                 PLoc::Reg(r, ..) | PLoc::Ref(r, ..) => {
-                    self.emit(instrs::cp(atr(arg), r));
+                    self.emit_cp(atr(arg), r);
                     continue;
                 }
             };
@@ -83,13 +83,13 @@ impl HbvmBackend {
             if nodes.is_unlocked(arg) {
                 self.emit(instrs::addi64(rg, reg::STACK_PTR, self.offsets[arg as usize] as _));
             }
-            self.emit(instrs::cp(atr(arg), rg));
+            self.emit_cp(atr(arg), rg);
         }
 
         let mut alloc_buf = vec![];
         for (i, block) in res.blocks.iter().enumerate() {
             self.offsets[block.entry as usize] = self.code.len() as _;
-            for &nid in &res.instrs[block.range.clone()] {
+            for &nid in &res.instrs[block.range()] {
                 if nid == VOID {
                     continue;
                 }
@@ -289,7 +289,7 @@ impl HbvmBackend {
                     match ret {
                         Some(PLoc::WideReg(..)) => {}
                         Some(PLoc::Reg(..)) if node.ty.loc(tys) == Loc::Stack => {}
-                        Some(PLoc::Reg(r, ..)) => self.emit(instrs::cp(atr(nid), r)),
+                        Some(PLoc::Reg(r, ..)) => self.emit_cp(atr(nid), r),
                         None | Some(PLoc::Ref(..)) => {}
                     }
                 }
@@ -309,6 +309,12 @@ impl HbvmBackend {
             tail,
         )
     }
+
+    fn emit_cp(&mut self, dst: Reg, src: Reg) {
+        if dst != 0 {
+            self.emit(instrs::cp(dst, src));
+        }
+    }
 }
 
 struct Function<'a> {
@@ -323,7 +329,7 @@ impl core::fmt::Debug for Function<'_> {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         for block in &self.func.blocks {
             writeln!(f, "{:?}", self.nodes[block.entry].kind)?;
-            for &instr in &self.func.instrs[block.range.clone()] {
+            for &instr in &self.func.instrs[block.range()] {
                 writeln!(f, "{:?}", self.nodes[instr].kind)?;
             }
         }
@@ -344,9 +350,11 @@ impl<'a> Function<'a> {
     }
 
     fn add_block(&mut self, entry: Nid) {
-        self.func
-            .blocks
-            .push(Block { range: self.func.instrs.len()..self.func.instrs.len(), entry });
+        self.func.blocks.push(Block {
+            start: self.func.instrs.len() as _,
+            end: self.func.instrs.len() as _,
+            entry,
+        });
         self.func.backrefs[entry as usize] = self.func.blocks.len() as u16 - 1;
     }
 
@@ -357,7 +365,7 @@ impl<'a> Function<'a> {
             self.func.instrs.push(exit);
         }
         let prev = self.func.blocks.last_mut().unwrap();
-        prev.range.end = self.func.instrs.len();
+        prev.end = self.func.instrs.len() as _;
     }
 
     fn add_instr(&mut self, nid: Nid) {
@@ -562,6 +570,8 @@ impl<'a> Regalloc<'a> {
     fn run_low(&mut self) {
         self.res.bundles.clear();
         self.res.node_to_reg.clear();
+        #[cfg(debug_assertions)]
+        self.res.marked.clear();
         self.res.node_to_reg.resize(self.nodes.vreg_count(), 0);
 
         debug_assert!(self.res.dfs_buf.is_empty());
@@ -591,7 +601,7 @@ impl<'a> Regalloc<'a> {
 
         let instrs = mem::take(&mut self.res.instrs);
         for &inst in &instrs {
-            if self.res.visited.get(inst) || inst == 0 {
+            if self.nodes[inst].has_no_value() || self.res.visited.get(inst) || inst == 0 {
                 continue;
             }
             self.append_bundle(inst, &mut bundle, None);
@@ -599,13 +609,18 @@ impl<'a> Regalloc<'a> {
         self.res.instrs = instrs;
     }
 
-    fn append_bundle(&mut self, inst: Nid, bundle: &mut Bundle, prefered: Option<usize>) {
+    fn collect_bundle(&mut self, inst: Nid, into: &mut Bundle) {
         let dom = self.nodes.idom_of(inst);
+        self.res.dfs_seem.clear(self.nodes.values.len());
         for (cursor, uinst) in self.nodes.uses_of(inst) {
+            if !self.res.dfs_seem.set(uinst) {
+                continue;
+            }
             #[cfg(debug_assertions)]
-            self.res.marked.insert((inst, uinst));
+            debug_assert!(self.res.marked.insert((inst, uinst)));
+
             self.reverse_cfg_dfs(cursor, dom, |s, n, b| {
-                let mut range = b.range.clone();
+                let mut range = b.range();
                 debug_assert!(range.start < range.end);
                 range.start = range.start.max(s.instr_of(inst).map_or(0, |n| n + 1) as usize);
                 debug_assert!(range.start < range.end, "{:?}", range);
@@ -621,32 +636,37 @@ impl<'a> Regalloc<'a> {
                 range.end = new;
                 debug_assert!(range.start < range.end, "{:?} {inst} {uinst}", range);
 
-                bundle.add(range);
+                into.add(range);
             });
         }
+    }
 
-        if !bundle.taken.contains(&true) {
+    fn append_bundle(&mut self, inst: Nid, tmp: &mut Bundle, prefered: Option<usize>) {
+        self.collect_bundle(inst, tmp);
+
+        if tmp.is_empty() {
             self.res.node_to_reg[inst as usize] = u8::MAX;
             return;
         }
 
         if let Some(prefered) = prefered
-            && !self.res.bundles[prefered].overlaps(bundle)
+            && !self.res.bundles[prefered].overlaps(tmp)
         {
-            self.res.bundles[prefered].merge(bundle);
-            bundle.clear();
+            self.res.bundles[prefered].merge(tmp);
+            tmp.clear();
             self.res.node_to_reg[inst as usize] = prefered as Reg + 1;
-        } else {
-            match self.res.bundles.iter_mut().enumerate().find(|(_, b)| !b.overlaps(bundle)) {
-                Some((i, other)) => {
-                    other.merge(bundle);
-                    bundle.clear();
-                    self.res.node_to_reg[inst as usize] = i as Reg + 1;
-                }
-                None => {
-                    self.res.bundles.push(mem::replace(bundle, Bundle::new(bundle.taken.len())));
-                    self.res.node_to_reg[inst as usize] = self.res.bundles.len() as Reg;
-                }
+            return;
+        }
+
+        match self.res.bundles.iter_mut().enumerate().find(|(_, b)| !b.overlaps(tmp)) {
+            Some((i, other)) => {
+                other.merge(tmp);
+                tmp.clear();
+                self.res.node_to_reg[inst as usize] = i as Reg + 1;
+            }
+            None => {
+                self.res.bundles.push(tmp.take());
+                self.res.node_to_reg[inst as usize] = self.res.bundles.len() as Reg;
             }
         }
     }
@@ -659,13 +679,12 @@ impl<'a> Regalloc<'a> {
     ) {
         debug_assert!(self.res.dfs_buf.is_empty());
         self.res.dfs_buf.push(from);
-        self.res.dfs_seem.clear(self.nodes.values.len());
 
         debug_assert!(self.nodes.dominates(until, from));
 
         while let Some(nid) = self.res.dfs_buf.pop() {
             debug_assert!(self.nodes.dominates(until, nid), "{until} {:?}", self.nodes[until]);
-            each(self, nid, self.res.blocks[self.block_of(nid) as usize].clone());
+            each(self, nid, self.res.blocks[self.block_of(nid) as usize]);
             if nid == until {
                 continue;
             }
@@ -729,10 +748,25 @@ impl Bundle {
     fn clear(&mut self) {
         self.taken.fill(false);
     }
+
+    fn is_empty(&self) -> bool {
+        !self.taken.contains(&true)
+    }
+
+    fn take(&mut self) -> Self {
+        mem::replace(self, Self::new(self.taken.len()))
+    }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Copy)]
 struct Block {
-    range: Range<usize>,
+    start: u16,
+    end: u16,
     entry: Nid,
 }
+
+impl Block {
+    pub fn range(&self) -> Range<usize> {
+        self.start as usize..self.end as usize
+    }
+}
diff --git a/lang/tests/son_tests_const_folding_with_arg.txt b/lang/tests/son_tests_const_folding_with_arg.txt
index 8723147..5aa16aa 100644
--- a/lang/tests/son_tests_const_folding_with_arg.txt
+++ b/lang/tests/son_tests_const_folding_with_arg.txt
@@ -1,7 +1,6 @@
 main:
-    CP r0, r2
     CP r1, r0
     JALA r0, r31, 0a
-code size: 25
+code size: 22
 ret: 0
 status: Ok(())
diff --git a/lang/tests/son_tests_different_function_destinations.txt b/lang/tests/son_tests_different_function_destinations.txt
index 5e6a775..18f9921 100644
--- a/lang/tests/son_tests_different_function_destinations.txt
+++ b/lang/tests/son_tests_different_function_destinations.txt
@@ -1,6 +1,6 @@
 main:
-    ADDI64 r254, r254, -160d
-    ST r31, r254, 80a, 80h
+    ADDI64 r254, r254, -152d
+    ST r31, r254, 80a, 72h
     LRA r32, r0, :glob_stru
     JAL r31, r0, :new_stru
     ST r1, r32, 0a, 16h
@@ -62,14 +62,14 @@ main:
     ST r33, r32, 8a, 8h
     CP r32, r34
     JMP :7
- 3: MULI64 r39, r32, 16d
-    ADD64 r39, r37, r39
+ 3: MULI64 r34, r32, 16d
+    ADD64 r34, r37, r34
     JAL r31, r0, :new_stru
-    ST r1, r39, 0a, 16h
+    ST r1, r34, 0a, 16h
     ADD64 r32, r32, r35
     JMP :8
- 1: LD r31, r254, 80a, 80h
-    ADDI64 r254, r254, 160d
+ 1: LD r31, r254, 80a, 72h
+    ADDI64 r254, r254, 152d
     JALA r0, r31, 0a
 new_stru:
     ADDI64 r254, r254, -24d
diff --git a/lang/tests/son_tests_directives.txt b/lang/tests/son_tests_directives.txt
index 7dca40b..a29e1a8 100644
--- a/lang/tests/son_tests_directives.txt
+++ b/lang/tests/son_tests_directives.txt
@@ -14,12 +14,11 @@ main:
     CP r6, r13
     LD r3, r14, 0a, 16h
     ECA 
-    CP r0, r1
     CP r1, r0
     LD r32, r254, 16a, 32h
     ADDI64 r254, r254, 48d
     JALA r0, r31, 0a
 ev: Ecall
-code size: 183
+code size: 180
 ret: 0
 status: Ok(())
diff --git a/lang/tests/son_tests_fb_driver.txt b/lang/tests/son_tests_fb_driver.txt
index 06347e7..c3f362b 100644
--- a/lang/tests/son_tests_fb_driver.txt
+++ b/lang/tests/son_tests_fb_driver.txt
@@ -11,7 +11,6 @@ main:
     ADDI64 r254, r254, -64d
     ST r31, r254, 0a, 64h
     JAL r31, r0, :check_platform
-    CP r0, r1
     CP r33, r0
     LI64 r36, 30d
     LI64 r37, 100d
@@ -59,6 +58,6 @@ x86_fb_ptr:
     LD r32, r254, 0a, 8h
     ADDI64 r254, r254, 8d
     JALA r0, r31, 0a
-code size: 428
+code size: 425
 ret: 3000
 status: Ok(())
diff --git a/lang/tests/son_tests_generic_type_mishap.txt b/lang/tests/son_tests_generic_type_mishap.txt
index 6037f7e..cbdeecb 100644
--- a/lang/tests/son_tests_generic_type_mishap.txt
+++ b/lang/tests/son_tests_generic_type_mishap.txt
@@ -6,11 +6,10 @@ main:
     ADDI64 r254, r254, 16d
     JALA r0, r31, 0a
 opaque:
-    CP r0, r2
     JALA r0, r31, 0a
 process:
-    ADDI64 r254, r254, -64d
-    ST r31, r254, 16a, 48h
+    ADDI64 r254, r254, -56d
+    ST r31, r254, 16a, 40h
     LI64 r32, 1000d
     ADDI64 r33, r254, 0d
     ST r0, r254, 0a, 1h
@@ -18,16 +17,16 @@ process:
     JMP :1
  0: CP r2, r33
     JAL r31, r0, :opaque
-    LD r35, r254, 0a, 1h
-    ANDI r35, r35, 255d
-    JEQ r35, r0, :2
+    LD r34, r254, 0a, 1h
+    ANDI r34, r34, 255d
+    JEQ r34, r0, :2
     JMP :3
  2: ADDI64 r32, r32, -1d
  1: JMP :4
- 3: LD r31, r254, 16a, 48h
-    ADDI64 r254, r254, 64d
+ 3: LD r31, r254, 16a, 40h
+    ADDI64 r254, r254, 56d
     JALA r0, r31, 0a
 timed out
-code size: 251
+code size: 248
 ret: 0
 status: Ok(())
diff --git a/lang/tests/son_tests_inline.txt b/lang/tests/son_tests_inline.txt
index 753a25b..c40a6f5 100644
--- a/lang/tests/son_tests_inline.txt
+++ b/lang/tests/son_tests_inline.txt
@@ -1,12 +1,12 @@
 main:
-    ADDI64 r254, r254, -24d
-    ST r32, r254, 0a, 24h
+    ADDI64 r254, r254, -16d
+    ST r32, r254, 0a, 16h
     LI64 r13, 8d
     CP r2, r13
     ECA 
     LI64 r14, 6d
-    LRA r15, r0, :gb
-    LD r13, r15, 0a, 8h
+    LRA r13, r0, :gb
+    LD r13, r13, 0a, 8h
     CMPU r13, r13, r0
     CMPUI r13, r13, 0d
     OR r13, r13, r0
@@ -17,8 +17,8 @@ main:
  0: LI64 r13, 1d
  1: SUB64 r13, r13, r14
     CP r1, r13
-    LD r32, r254, 0a, 24h
-    ADDI64 r254, r254, 24d
+    LD r32, r254, 0a, 16h
+    ADDI64 r254, r254, 16d
     JALA r0, r31, 0a
 code size: 179
 ret: 0
diff --git a/lang/tests/son_tests_intcast_store.txt b/lang/tests/son_tests_intcast_store.txt
index 8639a9e..b9a12d6 100644
--- a/lang/tests/son_tests_intcast_store.txt
+++ b/lang/tests/son_tests_intcast_store.txt
@@ -1,31 +1,29 @@
 main:
-    ADDI64 r254, r254, -72d
-    ST r31, r254, 16a, 56h
+    ADDI64 r254, r254, -56d
+    ST r31, r254, 16a, 40h
     ADDI64 r32, r254, 0d
     ADDI64 r33, r254, 8d
     ST r0, r254, 0a, 8h
     ST r0, r254, 8a, 8h
-    LI64 r36, 1024d
+    LI64 r34, 1024d
     CP r2, r33
     CP r3, r32
-    CP r4, r36
+    CP r4, r34
     JAL r31, r0, :set
     CP r32, r1
     ANDI r32, r32, 4294967295d
     CP r1, r32
-    LD r31, r254, 16a, 56h
-    ADDI64 r254, r254, 72d
+    LD r31, r254, 16a, 40h
+    ADDI64 r254, r254, 56d
     JALA r0, r31, 0a
 set:
     ADDI64 r254, r254, -8d
     ST r32, r254, 0a, 8h
-    CP r0, r2
-    CP r0, r3
     CP r13, r4
     CP r1, r13
     LD r32, r254, 0a, 8h
     ADDI64 r254, r254, 8d
     JALA r0, r31, 0a
-code size: 229
+code size: 223
 ret: 1024
 status: Ok(())
diff --git a/lang/tests/son_tests_integer_inference_issues.txt b/lang/tests/son_tests_integer_inference_issues.txt
index 1c49891..b62454f 100644
--- a/lang/tests/son_tests_integer_inference_issues.txt
+++ b/lang/tests/son_tests_integer_inference_issues.txt
@@ -24,10 +24,9 @@ main:
     CP r2, r0
     CP r3, r32
     JAL r31, r0, :integer_range
-    CP r0, r1
     LD r31, r254, 0a, 24h
     ADDI64 r254, r254, 24d
     JALA r0, r31, 0a
-code size: 215
+code size: 212
 ret: 42
 status: Ok(())
diff --git a/lang/tests/son_tests_memory_swap.txt b/lang/tests/son_tests_memory_swap.txt
index 02b3dea..0dbc2d9 100644
--- a/lang/tests/son_tests_memory_swap.txt
+++ b/lang/tests/son_tests_memory_swap.txt
@@ -20,8 +20,8 @@ main:
     JAL r31, r0, :decide
     ADDI64 r34, r254, 24d
     BMC r32, r34, 24h
-    LI64 r36, 1d
-    CP r2, r36
+    LI64 r35, 1d
+    CP r2, r35
     CP r1, r34
     JAL r31, r0, :decide
     ADDI64 r36, r254, 0d
diff --git a/lang/tests/son_tests_more_if_opts.txt b/lang/tests/son_tests_more_if_opts.txt
index e6c9653..c53e42d 100644
--- a/lang/tests/son_tests_more_if_opts.txt
+++ b/lang/tests/son_tests_more_if_opts.txt
@@ -4,7 +4,6 @@ main:
     JAL r31, r0, :opaque
     CP r33, r1
     JAL r31, r0, :opaque
-    CP r0, r1
     JNE r33, r0, :0
     CP r32, r0
     JMP :1
@@ -19,6 +18,6 @@ main:
 opaque:
     CP r1, r0
     JALA r0, r31, 0a
-code size: 153
+code size: 150
 ret: 0
 status: Ok(())
diff --git a/lang/tests/son_tests_nullable_types.txt b/lang/tests/son_tests_nullable_types.txt
index ddfbacd..ad4afa5 100644
--- a/lang/tests/son_tests_nullable_types.txt
+++ b/lang/tests/son_tests_nullable_types.txt
@@ -7,8 +7,8 @@ decide:
     ADDI64 r254, r254, 8d
     JALA r0, r31, 0a
 main:
-    ADDI64 r254, r254, -144d
-    ST r31, r254, 80a, 64h
+    ADDI64 r254, r254, -136d
+    ST r31, r254, 80a, 56h
     JAL r31, r0, :decide
     CP r32, r1
     CP r33, r0
@@ -57,22 +57,22 @@ main:
  9: ADDI64 r33, r254, 40d
     JAL r31, r0, :new_foo
     ST r1, r33, 0a, 16h
-    LD r37, r254, 40a, 8h
-    JNE r37, r0, :10
+    LD r36, r254, 40a, 8h
+    JNE r36, r0, :10
     LI64 r32, 999d
     CP r1, r32
     JMP :3
-10: LRA r37, r0, :"foo\0"
-    CP r4, r37
+10: LRA r36, r0, :"foo\0"
+    CP r4, r36
     LD r2, r33, 0a, 16h
     JAL r31, r0, :use_foo
     ADDI64 r33, r254, 0d
     JAL r31, r0, :no_foo
     ST r1, r33, 0a, 16h
     JAL r31, r0, :decide
-    CP r37, r1
-    ANDI r37, r37, 255d
-    JNE r37, r0, :11
+    CP r36, r1
+    ANDI r36, r36, 255d
+    JNE r36, r0, :11
     JMP :12
 11: ST r34, r254, 0a, 8h
     ST r35, r254, 8a, 8h
@@ -102,8 +102,8 @@ main:
     ANDI r32, r32, 65535d
     SUB64 r32, r32, r33
     CP r1, r32
- 3: LD r31, r254, 80a, 64h
-    ADDI64 r254, r254, 144d
+ 3: LD r31, r254, 80a, 56h
+    ADDI64 r254, r254, 136d
     JALA r0, r31, 0a
 new_bar:
     ADDI64 r254, r254, -48d
@@ -144,10 +144,8 @@ use_foo:
     ADDI64 r254, r254, -16d
     ST r2, r254, 0a, 16h
     ADDI64 r2, r254, 0d
-    CP r0, r2
-    CP r0, r4
     ADDI64 r254, r254, 16d
     JALA r0, r31, 0a
-code size: 1246
+code size: 1240
 ret: 0
 status: Ok(())
diff --git a/lang/tests/son_tests_only_break_loop.txt b/lang/tests/son_tests_only_break_loop.txt
index 1c74502..b491767 100644
--- a/lang/tests/son_tests_only_break_loop.txt
+++ b/lang/tests/son_tests_only_break_loop.txt
@@ -32,9 +32,7 @@ main:
     ADDI64 r254, r254, 32d
     JALA r0, r31, 0a
 outb:
-    CP r0, r2
-    CP r0, r3
     JALA r0, r31, 0a
-code size: 257
+code size: 251
 ret: 1
 status: Ok(())
diff --git a/lang/tests/son_tests_pointers.txt b/lang/tests/son_tests_pointers.txt
index 3ef067a..b74bd3b 100644
--- a/lang/tests/son_tests_pointers.txt
+++ b/lang/tests/son_tests_pointers.txt
@@ -1,9 +1,8 @@
 drop:
-    CP r0, r2
     JALA r0, r31, 0a
 main:
-    ADDI64 r254, r254, -48d
-    ST r31, r254, 8a, 40h
+    ADDI64 r254, r254, -40d
+    ST r31, r254, 8a, 32h
     ADDI64 r32, r254, 0d
     LI64 r33, 1d
     ST r33, r254, 0a, 8h
@@ -14,8 +13,8 @@ main:
     LD r32, r254, 0a, 8h
     ADDI64 r32, r32, -2d
     CP r1, r32
-    LD r31, r254, 8a, 40h
-    ADDI64 r254, r254, 48d
+    LD r31, r254, 8a, 32h
+    ADDI64 r254, r254, 40d
     JALA r0, r31, 0a
 modify:
     ADDI64 r254, r254, -16d
@@ -26,6 +25,6 @@ modify:
     LD r32, r254, 0a, 16h
     ADDI64 r254, r254, 16d
     JALA r0, r31, 0a
-code size: 247
+code size: 244
 ret: 0
 status: Ok(())
diff --git a/lang/tests/son_tests_request_page.txt b/lang/tests/son_tests_request_page.txt
index 105dd89..9cc0b1a 100644
--- a/lang/tests/son_tests_request_page.txt
+++ b/lang/tests/son_tests_request_page.txt
@@ -20,11 +20,9 @@ create_back_buffer:
  2: JLTS r32, r33, :3
     CP r2, r34
     JAL r31, r0, :request_page
-    CP r0, r1
     JMP :4
  3: CP r2, r32
     JAL r31, r0, :request_page
-    CP r0, r1
  4: SUB64 r32, r32, r33
     JMP :5
  1: LD r31, r254, 0a, 48h
@@ -36,29 +34,28 @@ main:
     LI64 r32, 400d
     CP r2, r32
     JAL r31, r0, :create_back_buffer
-    CP r0, r1
     LD r31, r254, 0a, 24h
     ADDI64 r254, r254, 24d
     JALA r0, r31, 0a
 request_page:
-    ADDI64 r254, r254, -40d
-    ST r32, r254, 0a, 40h
+    ADDI64 r254, r254, -32d
+    ST r32, r254, 0a, 32h
     CP r13, r2
     LRA r14, r0, :"\0\u{1}xxxxxxxx\0"
     ST r13, r14, 1a, 1h
-    LI64 r15, 12d
-    LI64 r16, 2d
-    LI64 r17, 3d
-    CP r2, r17
-    CP r3, r16
+    LI64 r13, 12d
+    LI64 r15, 2d
+    LI64 r16, 3d
+    CP r2, r16
+    CP r3, r15
     CP r4, r14
-    CP r5, r15
+    CP r5, r13
     ECA 
     CP r13, r1
     CP r1, r13
-    LD r32, r254, 0a, 40h
-    ADDI64 r254, r254, 40d
+    LD r32, r254, 0a, 32h
+    ADDI64 r254, r254, 32d
     JALA r0, r31, 0a
-code size: 408
+code size: 399
 ret: 42
 status: Ok(())
diff --git a/lang/tests/son_tests_storing_into_nullable_struct.txt b/lang/tests/son_tests_storing_into_nullable_struct.txt
index 23eccd9..06f1c06 100644
--- a/lang/tests/son_tests_storing_into_nullable_struct.txt
+++ b/lang/tests/son_tests_storing_into_nullable_struct.txt
@@ -7,7 +7,6 @@ do_stuff:
     ADDI64 r254, r254, 8d
     JALA r0, r31, 0a
 just_read:
-    CP r0, r2
     JALA r0, r31, 0a
 main:
     ADDI64 r254, r254, -88d
@@ -75,6 +74,6 @@ optionala:
     LD r32, r254, 48a, 32h
     ADDI64 r254, r254, 80d
     JALA r0, r31, 0a
-code size: 670
+code size: 667
 ret: 100
 status: Ok(())
diff --git a/lang/tests/son_tests_wide_ret.txt b/lang/tests/son_tests_wide_ret.txt
index 5a354e8..c7b7006 100644
--- a/lang/tests/son_tests_wide_ret.txt
+++ b/lang/tests/son_tests_wide_ret.txt
@@ -17,8 +17,6 @@ main:
 maina:
     ADDI64 r254, r254, -68d
     ST r31, r254, 20a, 48h
-    CP r0, r3
-    CP r0, r4
     ADDI64 r32, r254, 16d
     JAL r31, r0, :small_struct
     ST r1, r32, 0a, 4h
@@ -55,6 +53,6 @@ small_struct:
     LD r32, r254, 4a, 8h
     ADDI64 r254, r254, 12d
     JALA r0, r31, 0a
-code size: 591
+code size: 585
 ret: 2
 status: Ok(())