diff --git a/src/sm_84.c b/src/sm_84.c
index 7a19b54..cf49b1e 100644
--- a/src/sm_84.c
+++ b/src/sm_84.c
@@ -1221,7 +1221,6 @@ void DrawPlm(uint16 k) {  // 0x848DAA
   VramWriteEntry *v25;
   int16 v28;
   int16 v31;
-  int16 v33;
   uint16 v35;
   uint16 a;
 
@@ -1318,15 +1317,9 @@ LABEL_70:
                     addr = R3_.addr + 2 * R22_;
                   v31 = *(uint16 *)RomPtr_84orRAM(addr);
                   if (v31) {
-                    v31 = (uint8)v31;
-                    if ((v31 & 0x80) != 0)
-                      v31 |= 0xFF00u;
-                    g_word_7E001E = plm_x_block + v31;
+                    g_word_7E001E = plm_x_block + (int8)v31;
                     uint16 v32 = addr + 1;
-                    v33 = *RomPtr_84orRAM(v32);
-                    if ((v33 & 0x80) != 0)
-                      v33 |= 0xFF00u;
-                    R32 = plm_y_block + v33;
+                    R32 = plm_y_block + (int8)*RomPtr_84orRAM(v32);
                     v1 = v32 + 1;
                     goto LABEL_2;
                   }
diff --git a/src/sm_86.c b/src/sm_86.c
index 8807287..653b619 100644
--- a/src/sm_86.c
+++ b/src/sm_86.c
@@ -545,15 +545,8 @@ uint16 EprojInstr_Goto(uint16 k, uint16 j) {  // 0x8681AB
 }
 
 uint16 EprojInstr_GotoRel(uint16 k, uint16 j) {  // 0x8681B0
-  int16 v2;
-
   R18_ = j;
-  LOBYTE(v2) = HIBYTE(*(uint16 *)RomPtr_86(j - 1));
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  else
-    v2 = (uint8)v2;
-  return R18_ + v2;
+  return R18_ + (int8)RomPtr_86(j);
 }
 
 uint16 EprojInstr_DecTimerAndGotoIfNonZero(uint16 k, uint16 j) {  // 0x8681C6
@@ -835,15 +828,9 @@ void GetValuesForScreenShaking(void) {  // 0x868427
 }
 
 uint8 EprojColl_8506(void) {  // 0x868506
-  int16 v1;
-
-  LOBYTE(v1) = BTS[cur_block_index];
-  if ((uint8)v1) {
-    if ((BTS[cur_block_index] & 0x80) != 0)
-      v1 |= 0xFF00u;
-    else
-      v1 = (uint8)v1;
-    cur_block_index += v1;
+  uint8 t = BTS[cur_block_index];
+  if (t) {
+    cur_block_index += (int8)t;
     return 0xff;
   }
   return 0;
@@ -1579,60 +1566,30 @@ void EprojPreInstr_CrocomireBridgeCrumbling(uint16 k) {  // 0x8692BA
 }
 
 uint16 MoveEprojWithVelocity(uint16 k) {  // 0x8692D6
-  int16 v3;
-  char v4; // t0
-
   int v1 = k >> 1;
   uint16 v2 = enemy_projectile_x_vel[v1];
-  int carry = *((uint8 *)enemy_projectile_1A27 + k + 1) + LOBYTE(v2);
-  LOBYTE(v2) = carry;
-  *((uint8 *)enemy_projectile_1A27 + k + 1) = v2;
-  v2 &= 0xFF00u;
-  v4 = v2;
-  LOBYTE(v3) = HIBYTE(v2);
-  HIBYTE(v3) = v4;
-  if ((v3 & 0x80) != 0)
-    v3 |= 0xFF00u;
-  enemy_projectile_x_pos[v1] += v3 + (carry >> 8);
+  int carry = *((uint8 *)enemy_projectile_1A27 + k + 1) + (v2 & 0xff);
+  *((uint8 *)enemy_projectile_1A27 + k + 1) = carry;
+  enemy_projectile_x_pos[v1] += (int8)(v2 >> 8) + (carry >> 8);
   return MoveEprojWithVelocityY(k);
 }
 
 uint16 MoveEprojWithVelocityY(uint16 k) {  // 0x8692F3
-  int16 v3;
-  char v4; // t0
-
   int v1 = k >> 1;
   uint16 v2 = enemy_projectile_y_vel[v1];
-  int carry = *((uint8 *)enemy_projectile_y_subpos + k + 1) + LOBYTE(v2);
-  LOBYTE(v2) = carry;
-  *((uint8 *)enemy_projectile_y_subpos + k + 1) = v2;
-  v2 &= 0xFF00u;
-  v4 = v2;
-  LOBYTE(v3) = HIBYTE(v2);
-  HIBYTE(v3) = v4;
-  if ((v3 & 0x80) != 0)
-    v3 |= 0xFF00u;
-  uint16 result = enemy_projectile_y_pos[v1] + v3 + (carry >> 8);
+  int carry = *((uint8 *)enemy_projectile_y_subpos + k + 1) + (v2 & 0xff);
+  *((uint8 *)enemy_projectile_y_subpos + k + 1) = carry;
+  uint16 result = enemy_projectile_y_pos[v1] + (int8)(v2 >> 8) + (carry >> 8);
   enemy_projectile_y_pos[v1] = result;
   return result;
 }
 
 uint16 MoveEprojWithVelocityX(uint16 k) {  // 0x869311
-  int16 v3;
-  char v4; // t0
-
   int v1 = k >> 1;
   uint16 v2 = enemy_projectile_x_vel[v1];
-  int carry = *((uint8 *)enemy_projectile_1A27 + k + 1) + LOBYTE(v2);
-  LOBYTE(v2) = carry;
-  *((uint8 *)enemy_projectile_1A27 + k + 1) = v2;
-  v2 &= 0xFF00u;
-  v4 = v2;
-  LOBYTE(v3) = HIBYTE(v2);
-  HIBYTE(v3) = v4;
-  if ((v3 & 0x80) != 0)
-    v3 |= 0xFF00u;
-  uint16 result = enemy_projectile_x_pos[v1] + v3 + (carry >> 8);
+  int carry = *((uint8 *)enemy_projectile_1A27 + k + 1) + (v2 & 0xff);
+  *((uint8 *)enemy_projectile_1A27 + k + 1) = carry;
+  uint16 result = enemy_projectile_x_pos[v1] + (int8)(v2 >> 8) + (carry >> 8);
   enemy_projectile_x_pos[v1] = result;
   return result;
 }
diff --git a/src/sm_87.c b/src/sm_87.c
index a750346..cf54e92 100644
--- a/src/sm_87.c
+++ b/src/sm_87.c
@@ -110,15 +110,8 @@ uint16 AnimtilesInstr_Goto(uint16 k, uint16 j) {  // 0x8780B7
 }
 
 uint16 AnimtilesInstr_GotoRel(uint16 k, uint16 j) {  // 0x8780BC
-  int16 v2;
-
   animtiles_instruction = j;
-  LOBYTE(v2) = HIBYTE(*(uint16 *)RomPtr_87(j - 1));
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  else
-    v2 = (uint8)v2;
-  return animtiles_instruction + v2;
+  return j + (int8)*RomPtr_87(j);
 }
 
 uint16 AnimtilesInstr_DecrementTimerAndGoto(uint16 k, uint16 j) {  // 0x8780D4
diff --git a/src/sm_88.c b/src/sm_88.c
index 8c5141a..2584e86 100644
--- a/src/sm_88.c
+++ b/src/sm_88.c
@@ -660,15 +660,8 @@ uint16 HdmaobjInstr_Goto(uint8 db, uint16 k, uint16 j) {  // 0x8885EC
 }
 
 uint16 HdmaobjInstr_GotoRel(uint8 db, uint16 k, uint16 j) {  // 0x8885F1
-  int16 v2;
-
   R18_ = j;
-  LOBYTE(v2) = HIBYTE(*(uint16 *)RomPtrWithBank(db, j - 1));
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  else
-    v2 = (uint8)v2;
-  return R18_ + v2;
+  return j + (int8)*RomPtrWithBank(db, j);
 }
 
 uint16 HdmaobjInstr_DecrementAndGoto(uint8 db, uint16 k, uint16 j) {  // 0x888607
diff --git a/src/sm_8b.c b/src/sm_8b.c
index 288039a..5c9a4b1 100644
--- a/src/sm_8b.c
+++ b/src/sm_8b.c
@@ -1500,15 +1500,8 @@ uint16 CinematicSprInstr_ClearPreInstr(uint16 k, uint16 j) {  // 0x8B9457
 
 
 uint16 CinematicSprInstr_GotoRel(uint16 k, uint16 j) {  // 0x8B94A2
-  int16 v2;
-
   R18_ = j;
-  LOBYTE(v2) = HIBYTE(*(uint16 *)RomPtr_8B(j - 1));
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  else
-    v2 = (uint8)v2;
-  return R18_ + v2;
+  return j + (int8)*RomPtr_8B(j);
 }
 
 uint16 CinematicSprInstr_Goto(uint16 k, uint16 j) {  // 0x8B94BC
@@ -4286,18 +4279,12 @@ void CinematicFunction_Intro_Func58(uint16 k) {  // 0x8BBEB5
   unsigned int v9; // kr0C_4
   uint16 v4;
 
-  if (cinematic_function == (uint16)FUNC16(CinematicFunction_Intro_Func56)) {
+  if (cinematic_function == FUNC16(CinematicFunction_Intro_Func56)) {
     int v1 = k >> 1;
     uint16 v2 = cinematicspr_goto_timer[v1] + 128;
     cinematicspr_goto_timer[v1] = v2;
-    v3 = v2;
-    LOBYTE(v4) = HIBYTE(v2);
-    HIBYTE(v4) = v3;
-    R20_ = v4 & 0xFF00;
-    v4 = (uint8)v4;
-    if ((v4 & 0x80) != 0)
-      v4 |= 0xFF00u;
-    R18_ = v4;
+    R20_ = (v2 & 0xff) << 8;
+    R18_ = (int8)(v2 >> 8);
     uint16 v5 = cinematicspr_arr7[v1];
     bool v6 = __CFADD__uint16(R20_, v5);
     cinematicspr_arr7[v1] = R20_ + v5;
@@ -6200,25 +6187,15 @@ void CinematicFunction_Intro_Func149(void) {  // 0x8BE812
         }
         *((uint16 *)v3 + 7) = g_word_8BE9CF[v4 + 1] + v5;
         uint16 v23 = *((uint16 *)v3 + 6);
-        uint16 v6 = HIBYTE(v23);
-        if ((v23 & 0x8000u) != 0)
-          v6 |= 0xFF00u;
-        R18_ = v6;
-        LOBYTE(v7) = HIBYTE(v23);
-        HIBYTE(v7) = v23;
-        R20_ = v7 & 0xFF00;
+        R18_ = (int8)HIBYTE(v23);
+        R20_ = (v23 << 8) & 0xFF00;
         v8 = *((uint16 *)v3 + 2);
         bool v9 = __CFADD__uint16(R20_, v8);
         *((uint16 *)v3 + 2) = R20_ + v8;
         *((uint16 *)v3 + 1) += R18_ + v9;
         uint16 v24 = *((uint16 *)v3 + 7);
-        uint16 v10 = HIBYTE(v24);
-        if ((v24 & 0x8000u) != 0)
-          v10 |= 0xFF00u;
-        R18_ = v10;
-        LOBYTE(v11) = HIBYTE(v24);
-        HIBYTE(v11) = v24;
-        R20_ = v11 & 0xFF00;
+        R18_ = (int8)HIBYTE(v24);
+        R20_ = (v24 << 8) & 0xFF00;
         v12 = *((uint16 *)v3 + 4);
         v9 = __CFADD__uint16(R20_, v12);
         *((uint16 *)v3 + 4) = R20_ + v12;
diff --git a/src/sm_8d.c b/src/sm_8d.c
index 71d7f15..906244e 100644
--- a/src/sm_8d.c
+++ b/src/sm_8d.c
@@ -197,15 +197,8 @@ PairU16 PalInstr_Goto(uint16 k, uint16 j) {  // 0x8DC61E
 }
 
 PairU16 PalInstr_GotoRel(uint16 k, uint16 j) {  // 0x8DC623
-  int16 v2;
-
   R18_ = j;
-  LOBYTE(v2) = HIBYTE(*(uint16 *)RomPtr_8D(j - 1));
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  else
-    v2 = (uint8)v2;
-  return MakePairU16(k, R18_ + v2);
+  return MakePairU16(k, j + (int8)*RomPtr_8D(j));
 }
 
 PairU16 PalInstr_DecTimerGoto(uint16 k, uint16 j) {  // 0x8DC639
diff --git a/src/sm_90.c b/src/sm_90.c
index f2fc3b1..cbe9262 100644
--- a/src/sm_90.c
+++ b/src/sm_90.c
@@ -837,13 +837,11 @@ PairU16 Samus_CalcSpritemapPos(uint16 k) {
 }
 
 PairU16 Samus_CalcSpritemapPos_Default(uint16 j) {  // 0x908C94
-  uint16 v1 = *(&kPoseParams[0].y_offset_to_gfx + (uint16)(4 * j));
-  if ((v1 & 0x80) != 0)
-    v1 |= 0xFF00u;
+  int v1 = (int8)*(&kPoseParams[0].y_offset_to_gfx + 4 * j);
   R18_ = v1;
   samus_spritemap_y_pos = samus_y_pos - v1 - layer1_y_pos;
   samus_spritemap_x_pos = samus_x_pos - layer1_x_pos;
-  return MakePairU16(samus_x_pos - layer1_x_pos, samus_y_pos - v1 - layer1_y_pos);
+  return MakePairU16(samus_spritemap_x_pos, samus_spritemap_y_pos);
 }
 
 PairU16 Samus_CalcSpritemapPos_Standing(uint16 j) {  // 0x908CC3
@@ -890,13 +888,11 @@ PairU16 Samus_CalcSpritemapPos_Crouch(uint16 j) {  // 0x908D3C
   if (sign16((j >> 1) - kPose_35_FaceR_CrouchTrans) || !sign16(v1 - kPose_41_FaceL_Morphball_Ground)) {
     return Samus_CalcSpritemapPos_Default(j);
   } else {
-    uint16 v4 = byte_908D80[(uint16)(samus_anim_frame + 2 * (v1 - 53))];
-    if ((v4 & 0x80) != 0)
-      v4 |= 0xFF00u;
+    int v4 = byte_908D80[(uint16)(samus_anim_frame + 2 * (v1 - 53))];
     R18_ = v4;
     samus_spritemap_y_pos = v4 + samus_y_pos - layer1_y_pos;
     samus_spritemap_x_pos = samus_x_pos - layer1_x_pos;
-    return MakePairU16(samus_x_pos - layer1_x_pos, v4 + samus_y_pos - layer1_y_pos);
+    return MakePairU16(samus_x_pos - layer1_x_pos, samus_spritemap_y_pos);
   }
 }
 
@@ -907,14 +903,11 @@ PairU16 Samus_CalcSpritemapPos_Special(uint16 j) {  // 0x908D98
   -5, 0,  0,  4, -3, -5, -3,  4,
    0, 0,  4,  0,  0,  4,  0,  0,
   };
-  int16 v1;
-  uint16 v2;
+  int v1, v2;
 
   v1 = j >> 1;
-  if (j >> 1 == kPose_E8_FaceR_Drained_CrouchFalling || v1 == kPose_E9_FaceL_Drained_CrouchFalling) {
+  if (v1 == kPose_E8_FaceR_Drained_CrouchFalling || v1 == kPose_E9_FaceL_Drained_CrouchFalling) {
     v2 = byte_908DEF[samus_anim_frame];
-    if ((v2 & 0x80) != 0)
-      v2 |= 0xFF00u;
   } else {
     if (v1 != kPose_EA_FaceR_Drained_Stand && v1 != kPose_EB_FaceL_Drained_Stand || (int16)(samus_anim_frame - 5) < 0) {
       return Samus_CalcSpritemapPos_Default(j);
@@ -4578,14 +4571,8 @@ void Samus_ArmCannon_Draw(void) {  // 0x90C663
     }
     R24_ = kDrawArmCannon_Char[v3 >> 1];
     uint8 *v4 = RomPtr_90(R22_ + 2 * samus_anim_frame);
-    uint16 v5 = *v4;
-    if ((v5 & 0x80) != 0)
-      v5 |= 0xFF00u;
-    R18_ = v5;
-    uint16 v6 = v4[1];
-    if ((v6 & 0x80) != 0)
-      v6 |= 0xFF00u;
-    R20_ = v6;
+    R18_ = (int8)v4[0];
+    R20_ = (int8)v4[1];
     R22_ = *(&kPoseParams[0].y_offset_to_gfx + (uint16)(8 * samus_pose));
     uint16 v7 = oam_next_ptr;
     v8 = R18_ + samus_x_pos - layer1_x_pos;
@@ -5510,14 +5497,9 @@ void ProjPreInstr_WaveSba(uint16 k) {  // 0x90DA08
   } else if (sign16(projectile_bomb_x_speed[v4] - 2048)) {
     projectile_bomb_x_speed[v4] += 64;
   }
-  uint16 v5;
-  LOBYTE(v5) = HIBYTE(projectile_bomb_x_speed[v4]);
-  HIBYTE(v5) = projectile_bomb_x_speed[v4];
+  uint16 v5 = swap16(projectile_bomb_x_speed[v4]);
   R20_ = v5 & 0xFF00;
-  v5 = (uint8)v5;
-  if ((v5 & 0x80) != 0)
-    v5 |= 0xFF00u;
-  R18_ = v5;
+  R18_ = (int8)v5;
   uint16 v6 = projectile_bomb_x_subpos[v4];
   bool v7 = __CFADD__uint16(R20_, v6);
   projectile_bomb_x_subpos[v4] = R20_ + v6;
@@ -5528,14 +5510,9 @@ void ProjPreInstr_WaveSba(uint16 k) {  // 0x90DA08
   } else if (sign16(projectile_variables[v4] - 2048)) {
     projectile_variables[v4] += 64;
   }
-  uint16 v8;
-  LOBYTE(v8) = HIBYTE(projectile_variables[v4]);
-  HIBYTE(v8) = projectile_variables[v4];
+  uint16 v8 = swap16(projectile_variables[v4]);
   R20_ = v8 & 0xFF00;
-  v8 = (uint8)v8;
-  if ((v8 & 0x80) != 0)
-    v8 |= 0xFF00u;
-  R18_ = v8;
+  R18_ = (int8)v8;
   uint16 v9 = projectile_bomb_y_subpos[v4];
   v7 = __CFADD__uint16(R20_, v9);
   projectile_bomb_y_subpos[v4] = R20_ + v9;
diff --git a/src/sm_94.c b/src/sm_94.c
index e44ed04..c7b8ead 100644
--- a/src/sm_94.c
+++ b/src/sm_94.c
@@ -976,15 +976,9 @@ uint8 BlockColl_Vert_Door(void) {  // 0x9493CE
 }
 
 uint8 BlockReact_HorizExt(void) {  // 0x949411
-  int16 v0;
-
-  LOBYTE(v0) = BTS[cur_block_index];
-  if ((uint8)v0) {
-    if ((BTS[cur_block_index] & 0x80) != 0)
-      v0 |= 0xFF00u;
-    else
-      v0 = (uint8)v0;
-    cur_block_index += v0;
+  uint8 t = BTS[cur_block_index];
+  if (t) {
+    cur_block_index += (int8)t;
     return 0xff; // special
   }
   return 0;
diff --git a/src/sm_9b.c b/src/sm_9b.c
index a42c057..b857c99 100644
--- a/src/sm_9b.c
+++ b/src/sm_9b.c
@@ -90,33 +90,12 @@ void ProjectileTrail_Func5(uint16 k, uint16 j) {  // 0x9BA3CC
     v5 = g_off_9BA4B3[projectile_type[v3] & 0xF] + 2 * (projectile_dir[v3] & 0xF);
   }
   uint16 v6 = *(uint16 *)RomPtr_9B(v5) + 4 * R22_;
-  LOBYTE(v5) = HIBYTE(*(uint16 *)RomPtr_9B(v6));
-  if ((v5 & 0x80) != 0)
-    v5 |= 0xFF00u;
-  else
-    v5 = (uint8)v5;
+  uint8 *p = RomPtr_9B(v6);
   int v7 = j >> 1;
-  projectiletrail_left_y_pos[v7] = R20_ + v5 - 4;
-  uint16 v8 = v6 - 1;
-  LOBYTE(v5) = HIBYTE(*(uint16 *)RomPtr_9B(v8));
-  if ((v5 & 0x80) != 0)
-    v5 |= 0xFF00u;
-  else
-    v5 = (uint8)v5;
-  projectiletrail_left_x_pos[v7] = R18_ + v5 - 4;
-  uint8 *v9 = RomPtr_9B(v8 + 1);
-  LOBYTE(v5) = HIBYTE(*((uint16 *)v9 + 1));
-  if ((v5 & 0x80) != 0)
-    v5 |= 0xFF00u;
-  else
-    v5 = (uint8)v5;
-  projectiletrail_right_y_pos[v7] = R20_ + v5 - 4;
-  LOBYTE(v5) = HIBYTE(*(uint16 *)(v9 + 1));
-  if ((v5 & 0x80) != 0)
-    v5 |= 0xFF00u;
-  else
-    v5 = (uint8)v5;
-  projectiletrail_right_x_pos[v7] = R18_ + v5 - 4;
+  projectiletrail_left_y_pos[v7] = R20_ + (int8)p[1] - 4;
+  projectiletrail_left_x_pos[v7] = R18_ + (int8)p[0] - 4;
+  projectiletrail_right_y_pos[v7] = R20_ + (int8)p[3] - 4;
+  projectiletrail_right_x_pos[v7] = R18_ + (int8)p[2] - 4;
 }
 
 void StartSamusDeathAnimation(void) {  // 0x9BB3A7
@@ -686,23 +665,12 @@ LABEL_8:;
     samus_anim_frame = v3 + 32;
   }
   if (samus_pose_x_dir == 4) {
-    v6 = kGrappleBeam_SwingingData2[v2];
-    if ((v6 & 0x80) != 0)
-      v6 |= 0xFF00u;
-    samus_x_pos = x_pos_of_start_of_grapple_beam + v6;
-    v5 = kGrappleBeam_SwingingData2[v2 + 1];
-    if ((v5 & 0x80) != 0)
-      v5 |= 0xFF00u;
+    samus_x_pos = x_pos_of_start_of_grapple_beam + (int8)kGrappleBeam_SwingingData2[v2];
+    samus_y_pos = y_pos_of_start_of_grapple_beam + (int8)kGrappleBeam_SwingingData2[v2 + 1];
   } else {
-    v4 = kGrappleBeam_SwingingData3[v2];
-    if ((v4 & 0x80) != 0)
-      v4 |= 0xFF00u;
-    samus_x_pos = x_pos_of_start_of_grapple_beam + v4;
-    v5 = kGrappleBeam_SwingingData3[v2 + 1];
-    if ((v5 & 0x80) != 0)
-      v5 |= 0xFF00u;
+    samus_x_pos = x_pos_of_start_of_grapple_beam + (int8)kGrappleBeam_SwingingData3[v2];
+    samus_y_pos = y_pos_of_start_of_grapple_beam + (int8)kGrappleBeam_SwingingData3[v2 + 1];
   }
-  samus_y_pos = y_pos_of_start_of_grapple_beam + v5;
   x_pos_of_start_of_grapple_beam_prevframe = x_pos_of_start_of_grapple_beam;
   y_pos_of_start_of_grapple_beam_prevframe = y_pos_of_start_of_grapple_beam;
   GrappleBeamFunc_BE98();
diff --git a/src/sm_a0.c b/src/sm_a0.c
index 339b9e0..affdc06 100644
--- a/src/sm_a0.c
+++ b/src/sm_a0.c
@@ -101,15 +101,7 @@ uint16 EnemyInstr_Goto(uint16 k, uint16 j) {  // 0xA080ED
 }
 
 uint16 EnemyInstr_GotoRel(uint16 k, uint16 j) {  // 0xA080F2
-  int16 v2;
-
-  R18_ = j;
-  LOBYTE(v2) = HIBYTE(*(uint16 *)RomPtr_A0(j - 1));
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  else
-    v2 = (uint8)v2;
-  return R18_ + v2;
+  return j + (int8)*RomPtr_A0(j);
 }
 
 uint16 EnemyInstr_DecTimerAndGoto(uint16 k, uint16 j) {  // 0xA08108
@@ -4465,15 +4457,9 @@ uint8 EnemyBlockCollVertReact_Slope_NonSquare(void) {  // 0xA0C51F
 }
 
 uint8 EnemyBlockCollReact_HorizExt(void) {  // 0xA0C619
-  int16 v0;
-
-  LOBYTE(v0) = BTS[cur_block_index];
-  if ((uint8)v0) {
-    if ((BTS[cur_block_index] & 0x80) != 0)
-      v0 |= 0xFF00u;
-    else
-      v0 = (uint8)v0;
-    cur_block_index += v0;
+  uint8 t = BTS[cur_block_index];
+  if (t) {
+    cur_block_index += (int8)t;
     return 0xff;
   }
   return 0;
diff --git a/src/sm_a2.c b/src/sm_a2.c
index 8a59376..703f40d 100644
--- a/src/sm_a2.c
+++ b/src/sm_a2.c
@@ -1499,15 +1499,13 @@ void GunshipTop_1(uint16 k) {  // 0xA2A784
   if (v3 || v4) {
     uint16 v5 = 2 * E0->gtp_var_C;
     E0->gtp_var_D = g_byte_A2A7CF[v5];
-    uint16 v6 = g_byte_A2A7CF[v5 + 1];
-    if ((v6 & 0x80) != 0)
-      v6 |= 0xFF00u;
+    uint16 v6 = (int8)g_byte_A2A7CF[v5 + 1];
     R18_ = v6;
     E0->base.y_pos += v6;
     Enemy_GunshipTop *E1 = Get_GunshipTop(k + 64);
-    E1->base.y_pos += R18_;
+    E1->base.y_pos += v6;
     Enemy_GunshipTop *E2 = Get_GunshipTop(k + 128);
-    E2->base.y_pos += R18_;
+    E2->base.y_pos += v6;
     E0->gtp_var_C = ((uint8)E0->gtp_var_C + 1) & 3;
   }
 }
diff --git a/src/sm_a7.c b/src/sm_a7.c
index d544334..875ccc7 100644
--- a/src/sm_a7.c
+++ b/src/sm_a7.c
@@ -2486,14 +2486,10 @@ void Phantoon_MoveInFigure8_LeftSideClockwise(uint16 j) {  // 0xA7D215
   for (R22_ = E->phant_var_C; R22_; --R22_) {
     R18_ = 2 * E->phant_var_A;
     uint8 *v2 = RomPtr_A7(R18_ + j);
-    uint16 v3 = *v2;
-    if ((v3 & 0x80) != 0)
-      v3 |= 0xFF00u;
+    uint16 v3 = (int8)v2[0];
     R18_ = v3;
     E->base.x_pos += v3;
-    uint16 v4 = v2[1];
-    if ((v4 & 0x80) != 0)
-      v4 |= 0xFF00u;
+    uint16 v4 = (int8)v2[1];
     R18_ = v4;
     E->base.y_pos += v4;
     uint16 v5 = E->phant_var_A + 1;
@@ -2513,14 +2509,10 @@ void Phantoon_MoveInFigure8_RightSideClockwise(uint16 j) {  // 0xA7D271
     do {
       R18_ = 2 * E->phant_var_A;
       uint8 *v4 = RomPtr_A7(R18_ + j);
-      uint16 v5 = *v4;
-      if ((v5 & 0x80) != 0)
-        v5 |= 0xFF00u;
+      uint16 v5 = (int8)*v4;
       R18_ = v5;
       E->base.x_pos -= v5;
-      uint16 v6 = v4[1];
-      if ((v6 & 0x80) != 0)
-        v6 |= 0xFF00u;
+      uint16 v6 = (int8)v4[1];
       R18_ = v6;
       E->base.y_pos -= v6;
       v7 = E->phant_var_A - 1;
@@ -2578,13 +2570,9 @@ void Phantoon_MoveInSwoopingPattern(uint16 k) {  // 0xA7D2D1
   } else if (sign16(v2->phant_var_C - 2048)) {
     v2->phant_var_C += 32;
   }
-  LOBYTE(v9) = HIBYTE(v2->phant_var_C);
-  HIBYTE(v9) = v2->phant_var_C;
+  v9 = swap16(v2->phant_var_C);
   R20_ = v9 & 0xFF00;
-  v9 = (uint8)v9;
-  if ((v9 & 0x80) != 0)
-    v9 |= 0xFF00u;
-  R18_ = v9;
+  R18_ = (int8)v9;
   x_subpos = v7->base.x_subpos;
   v11 = __CFADD__uint16(R20_, x_subpos);
   v7->base.x_subpos = R20_ + x_subpos;
@@ -2605,13 +2593,9 @@ void Phantoon_MoveInSwoopingPattern(uint16 k) {  // 0xA7D2D1
   } else if (sign16(v2->phant_var_D - 1536)) {
     v2->phant_var_D += 64;
   }
-  LOBYTE(v14) = HIBYTE(v2->phant_var_D);
-  HIBYTE(v14) = v2->phant_var_D;
+  v14 = swap16(v2->phant_var_D);
   R20_ = v14 & 0xFF00;
-  v14 = (uint8)v14;
-  if ((v14 & 0x80) != 0)
-    v14 |= 0xFF00u;
-  R18_ = v14;
+  R18_ = (int8)v14;
   y_subpos = v8->base.y_subpos;
   v11 = __CFADD__uint16(R20_, y_subpos);
   v8->base.y_subpos = R20_ + y_subpos;
@@ -3106,17 +3090,9 @@ void Phantoon_DyingPhantoonExplosions(uint16 k) {  // 0xA7D98B
   if (v2 || v3) {
     Enemy_Phantoon *E2 = Get_Phantoon(0x80);
     uint16 v5 = 4 * E2->phant_var_F;
-    uint16 v6 = g_byte_A7DA1D[v5];
-    if ((v6 & 0x80) != 0)
-      v6 |= 0xFF00u;
-    R18_ = v6;
     Enemy_Phantoon *E0 = Get_Phantoon(0);
-    R18_ = v6 + E0->base.x_pos;
-    uint16 v8 = g_byte_A7DA1D[v5 + 1];
-    if ((v8 & 0x80) != 0)
-      v8 |= 0xFF00u;
-    R20_ = v8;
-    R20_ = v8 + E0->base.y_pos;
+    R18_ = (int8)g_byte_A7DA1D[v5] + E0->base.x_pos;
+    R20_ = (int8)g_byte_A7DA1D[v5 + 1] + E0->base.y_pos;
     uint16 v11 = g_byte_A7DA1D[v5 + 2];
     SpawnEnemyProjectileWithRoomGfx(addr_kEproj_DustCloudExplosion, v11);
     if (v11 == 29)
diff --git a/src/sm_a9.c b/src/sm_a9.c
index 81bf688..af64026 100644
--- a/src/sm_a9.c
+++ b/src/sm_a9.c
@@ -2770,54 +2770,30 @@ uint8 MotherBrain_MoveSamusForFallingAfterBeam(void) {  // 0xA9BBE1
 }
 
 uint8 MotherBrain_MoveSamusVerticallyTowardsCeilingFloor(uint16 a) {  // 0xA9BBFD
-  int16 v1;
-  int16 v2;
-  char v3; // t0
-
   int carry = HIBYTE(samus_y_subpos) + LOBYTE(a);
-  LOBYTE(a) = carry;
-  HIBYTE(samus_y_subpos) = a;
-  HIBYTE(samus_prev_y_subpos) = a;
-  v1 = a & 0xFF00;
-  v3 = v1;
-  LOBYTE(v2) = HIBYTE(v1);
-  HIBYTE(v2) = v3;
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  uint16 v4 = samus_y_pos + v2 + (carry >> 8), v6;
+  HIBYTE(samus_y_subpos) = carry;
+  HIBYTE(samus_prev_y_subpos) = carry;
+  uint16 v4 = samus_y_pos + (int8)(a >> 8) + (carry >> 8), v6;
   if (sign16(v4 - 48)) {
     v6 = 48;
   } else {
     if (sign16(v4 - 192)) {
-      samus_y_pos = v4;
-      samus_prev_y_pos = v4;
+      samus_prev_y_pos = samus_y_pos = v4;
       return 0;
     }
     v6 = 192;
   }
-  samus_y_pos = v6;
-  samus_prev_y_pos = v6;
+  samus_prev_y_pos = samus_y_pos = v6;
   samus_y_subpos = 0;
   samus_prev_y_subpos = 0;
   return 1;
 }
 
 uint8 MotherBrain_MoveSamusHorizTowardsWall(uint16 a) {  // 0xA9BC3F
-  int16 v1;
-  int16 v2;
-  char v3; // t0
-
   int carry = HIBYTE(samus_x_subpos) + LOBYTE(a);
-  LOBYTE(a) = carry;
-  HIBYTE(samus_x_subpos) = a;
-  HIBYTE(samus_prev_x_subpos) = a;
-  v1 = a & 0xFF00;
-  v3 = v1;
-  LOBYTE(v2) = HIBYTE(v1);
-  HIBYTE(v2) = v3;
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  uint16 v4 = samus_x_pos + v2 + (carry >> 8);
+  HIBYTE(samus_x_subpos) = carry;
+  HIBYTE(samus_prev_x_subpos) = carry;
+  uint16 v4 = samus_x_pos + (int8)(a >> 8) + (carry >> 8);
   if (sign16(v4 - 235)) {
     samus_x_pos = v4;
     samus_prev_x_pos = v4;
@@ -3427,34 +3403,16 @@ void MotherBrain_Phase3_Neck_HyperBeamRecoil(void) {  // 0xA9C3CD
 }
 
 void MoveEnemyWithVelocity(void) {  // 0xA9C3EF
-  int16 v2;
-  char v3; // t0
-  int16 v5;
-  char v6; // t1
-
   EnemyData *v0 = gEnemyData(cur_enemy_index);
   uint16 ai_var_B = v0->ai_var_B;
   int carry = HIBYTE(v0->x_subpos) + LOBYTE(ai_var_B);
-  LOBYTE(ai_var_B) = carry;
-  HIBYTE(v0->x_subpos) = ai_var_B;
-  ai_var_B &= 0xFF00u;
-  v3 = ai_var_B;
-  LOBYTE(v2) = HIBYTE(ai_var_B);
-  HIBYTE(v2) = v3;
-  if ((v2 & 0x80) != 0)
-    v2 |= 0xFF00u;
-  v0->x_pos += v2 + (carry >> 8);
+  HIBYTE(v0->x_subpos) = carry;
+  v0->x_pos += (int8)(ai_var_B >> 8) + (carry >> 8);
+
   uint16 ai_var_C = v0->ai_var_C;
   carry = HIBYTE(v0->y_subpos) + LOBYTE(ai_var_C);
-  LOBYTE(ai_var_C) = carry;
-  HIBYTE(v0->y_subpos) = ai_var_C;
-  ai_var_C &= 0xFF00u;
-  v6 = ai_var_C;
-  LOBYTE(v5) = HIBYTE(ai_var_C);
-  HIBYTE(v5) = v6;
-  if ((v5 & 0x80) != 0)
-    v5 |= 0xFF00u;
-  v0->y_pos += v5 + (carry >> 8);
+  HIBYTE(v0->y_subpos) = carry;
+  v0->y_pos += (int8)(ai_var_C >> 8) + (carry >> 8);
 }
 
 void MotherBrain_SetBodyInstrs(uint16 a) {  // 0xA9C42D
@@ -3501,21 +3459,10 @@ uint16 sub_A9C46C(uint16 a, uint16 j) {  // 0xA9C46C
 }
 
 void Enemy_IncreaseYpos(uint16 k, uint16 a) {  // 0xA9C4A9
-  int16 v3;
-  int16 v4;
-  char v5; // t0
-
   EnemyData *v2 = gEnemyData(k);
   int carry = HIBYTE(v2->y_subpos) + LOBYTE(a);
-  LOBYTE(a) = carry;
-  HIBYTE(v2->y_subpos) = a;
-  v3 = a & 0xFF00;
-  v5 = v3;
-  LOBYTE(v4) = HIBYTE(v3);
-  HIBYTE(v4) = v5;
-  if ((v4 & 0x80) != 0)
-    v4 |= 0xFF00u;
-  v2->y_pos += v4 + (carry >> 8);
+  HIBYTE(v2->y_subpos) = carry;
+  v2->y_pos += (int8)(a >> 8) + (carry >> 8);
 }
 
 void Samus_DecrementAmmoDueToRainbowBeam(void) {  // 0xA9C4C4
@@ -4867,84 +4814,37 @@ void DeadMonsters_Func_2(uint16 k) {  // 0xA9D91D
 }
 
 uint8 DeadMonsters_Func_3(uint16 k) {  // 0xA9D961
-  int16 v2;
-  int16 v5;
-  uint16 v6;
-  char v7; // t0
-  int16 v9;
-  int16 v10;
-  char v11; // t1
-
   Enemy_DeadMonsters *E = Get_DeadMonsters(k);
   DeadMonsters_Func_4(k, E->dms_var_0A);
-  v2 = 32;
+  uint16 v2 = 32;
   if ((E->dms_var_0B & 0x8000u) == 0)
     v2 = 128;
   uint16 v3 = E->dms_var_0B + v2;
   E->dms_var_0B = v3;
   R18_ = v3;
   if (sign16(E->base.x_pos - 544)) {
-    HIBYTE(v9) = HIBYTE(R18_);
-    int full = HIBYTE(E->base.y_subpos) + LOBYTE(R18_);
-    LOBYTE(v9) = full;
-    HIBYTE(E->base.y_subpos) = v9;
-    v9 &= 0xFF00u;
-    v11 = v9;
-    LOBYTE(v10) = HIBYTE(v9);
-    HIBYTE(v10) = v11;
-    if ((v10 & 0x80) != 0)
-      v10 |= 0xFF00u;
-    uint16 v12 = E->base.y_pos + v10 + (full >> 8);
+    int full = HIBYTE(E->base.y_subpos) + LOBYTE(v3);
+    HIBYTE(E->base.y_subpos) = full;
+    uint16 v12 = E->base.y_pos + (int8)(v3 >> 8) + (full >> 8);
     E->base.y_pos = v12;
     return sign16(v12 - 184) == 0;
   } else {
-    uint16 v4 = R18_;
-    HIBYTE(R18_) = R18_;
-    LOBYTE(R18_) = 0;
-    v5 = v4 & 0xFF00;
-    if (v5 < 0)
-      v5 |= 0xFFu;
-    v7 = v5;
-    LOBYTE(v6) = HIBYTE(v5);
-    HIBYTE(v6) = v7;
-    R20_ = v6;
+    R18_ = v3 << 8;
+    R20_ = (int8)(v3 >> 8);
     return Enemy_MoveDown(k);
   }
 }
 
 void DeadMonsters_Func_4(uint16 k, uint16 a) {  // 0xA9D9C7
-  int16 v4;
-  uint16 v5;
-  char v6; // t0
-  int16 v7;
-  int16 v8;
-  char v9; // t1
-
   R18_ = a;
   Enemy_DeadMonsters *E = Get_DeadMonsters(k);
   if (sign16(E->base.x_pos - 544)) {
-    HIBYTE(v7) = HIBYTE(R18_);
-    int full = HIBYTE(E->base.x_subpos) + LOBYTE(R18_);
-    LOBYTE(v7) = full;
-    HIBYTE(E->base.x_subpos) = v7;
-    v7 &= 0xFF00u;
-    v9 = v7;
-    LOBYTE(v8) = HIBYTE(v7);
-    HIBYTE(v8) = v9;
-    if ((v8 & 0x80) != 0)
-      v8 |= 0xFF00u;
-    E->base.x_pos += v8 + (full >> 8);
+    int full = HIBYTE(E->base.x_subpos) + LOBYTE(a);
+    HIBYTE(E->base.x_subpos) = full;
+    E->base.x_pos += (int8)(a >> 8) + (full >> 8);
   } else {
-    uint16 v3 = R18_;
-    HIBYTE(R18_) = R18_;
-    LOBYTE(R18_) = 0;
-    v4 = v3 & 0xFF00;
-    if (v4 < 0)
-      v4 |= 0xFFu;
-    v6 = v4;
-    LOBYTE(v5) = HIBYTE(v4);
-    HIBYTE(v5) = v6;
-    R20_ = v5;
+    R18_ = a << 8;
+    R20_ = (int8)(a >> 8);
     Enemy_MoveRight_IgnoreSlopes(k);
   }
 }
@@ -6779,96 +6679,50 @@ uint8 Shitroid_AccelerateTowardsPoint(uint16 k, uint16 a) {  // 0xA9F5A6
 }
 
 void Shitroid_AccelerateTowardsY(uint16 k) {  // 0xA9F5B5
-  int16 v2;
-  int16 v3;
-  int16 v4;
-  int16 v5;
-  char v6; // t0
-  int16 v7;
-  int16 v8;
-  int16 v9;
-  char v10; // t1
-  int16 v11;
-
   Enemy_Shitroid *E = Get_Shitroid(k);
-  v2 = E->base.y_pos - R20_;
-  if (!v2)
-    goto LABEL_9;
+  int16 v2 = E->base.y_pos - R20_;
+  if (!v2) {
+    ++R28_;
+    return;
+  }
   if (v2 >= 0) {
-    v7 = E->shitr_var_C - R22_;
+    uint16 v7 = E->shitr_var_C - R22_;
     if (sign16(v7 + 1280))
       v7 = -1280;
     E->shitr_var_C = v7;
-    v8 = v7 & 0xFF00;
-    v10 = v8;
-    LOBYTE(v9) = HIBYTE(v8);
-    HIBYTE(v9) = v10;
-    if ((v9 & 0x80) != 0)
-      v9 |= 0xFF00u;
-    v11 = E->base.y_pos + v9;
-    if (v11 == R20_ || (int16)(v11 - R20_) < 0) {
+    if ((int16)(E->base.y_pos + (int8)(v7 >> 8) - R20_) <= 0) {
       E->shitr_var_C = 0;
       ++R28_;
     }
   } else {
-    v3 = R22_ + E->shitr_var_C;
+    uint16 v3 = R22_ + E->shitr_var_C;
     if (!sign16(v3 - 1280))
       v3 = 1280;
     E->shitr_var_C = v3;
-    v4 = v3 & 0xFF00;
-    v6 = v4;
-    LOBYTE(v5) = HIBYTE(v4);
-    HIBYTE(v5) = v6;
-    if ((v5 & 0x80) != 0)
-      v5 |= 0xFF00u;
-    if (!sign16(E->base.y_pos + v5 - R20_)) {
+    if ((int16)(E->base.y_pos + (int8)(v3 >> 8) - R20_) >= 0) {
       E->shitr_var_C = 0;
-LABEL_9:
       ++R28_;
     }
   }
 }
 
 void Shitroid_AccelerateTowardsX(uint16 k) {  // 0xA9F615
-  int16 v2;
-  int16 v3;
-  int16 v4;
-  char v5; // t0
-  int16 v6;
-  int16 v7;
-  int16 v8;
-  char v9; // t1
-  int16 v10;
-
   Enemy_Shitroid *E = Get_Shitroid(k);
   if ((int16)(E->base.x_pos - R18_) >= 0) {
-    v6 = E->shitr_var_B - R22_;
+    uint16 v6 = E->shitr_var_B - R22_;
     if (sign16(v6 + 1280))
       v6 = -1280;
     E->shitr_var_B = v6;
-    v7 = v6 & 0xFF00;
-    v9 = v7;
-    LOBYTE(v8) = HIBYTE(v7);
-    HIBYTE(v8) = v9;
-    if ((v8 & 0x80) != 0)
-      v8 |= 0xFF00u;
-    v10 = E->base.x_pos + v8;
-    if (v10 == R18_ || (int16)(v10 - R18_) < 0) {
+    if ((int16)(E->base.x_pos + (int8)(v6 >> 8) - R18_) <= 0) {
       E->shitr_var_B = 0;
       ++R28_;
     }
   } else {
-    v2 = R22_ + E->shitr_var_B;
+    uint16 v2 = R22_ + E->shitr_var_B;
     if (!sign16(v2 - 1280))
       v2 = 1280;
     E->shitr_var_B = v2;
-    v3 = v2 & 0xFF00;
-    v5 = v3;
-    LOBYTE(v4) = HIBYTE(v3);
-    HIBYTE(v4) = v5;
-    if ((v4 & 0x80) != 0)
-      v4 |= 0xFF00u;
-    if (!sign16(E->base.x_pos + v4 - R18_)) {
+    if ((int16)(E->base.x_pos + (int8)(v2 >> 8) - R18_) >= 0) {
       E->shitr_var_B = 0;
       ++R28_;
     }