diff --git a/src/amd/compiler/aco_register_allocation.cpp b/src/amd/compiler/aco_register_allocation.cpp
index 6ba71eb34b6..8c0c5aabcd1 100644
--- a/src/amd/compiler/aco_register_allocation.cpp
+++ b/src/amd/compiler/aco_register_allocation.cpp
@@ -462,23 +462,28 @@ unsigned
 get_subdword_operand_stride(chip_class chip, const aco_ptr<Instruction>& instr, unsigned idx,
                             RegClass rc)
 {
-   /* v_readfirstlane_b32 cannot use SDWA */
-   if (instr->opcode == aco_opcode::p_as_uniform)
-      return 4;
-   if (instr->isPseudo() && chip >= GFX8)
-      return rc.bytes() % 2 == 0 ? 2 : 1;
+   if (instr->isPseudo()) {
+      /* v_readfirstlane_b32 cannot use SDWA */
+      if (instr->opcode == aco_opcode::p_as_uniform)
+         return 4;
+      else if (chip >= GFX8)
+         return rc.bytes() % 2 == 0 ? 2 : 1;
+      else
+         return 4;
+   }
 
-   if (instr->opcode == aco_opcode::v_cvt_f32_ubyte0) {
-      return 1;
-   } else if (can_use_SDWA(chip, instr, false)) {
-      return rc.bytes() % 2 == 0 ? 2 : 1;
-   } else if (rc.bytes() == 2 && can_use_opsel(chip, instr->opcode, idx, 1)) {
-      return 2;
-   } else if (instr->isVOP3P()) {
-      return 2;
+   assert(rc.bytes() <= 2);
+   if (instr->isVALU()) {
+      if (can_use_SDWA(chip, instr, false))
+         return rc.bytes();
+      if (can_use_opsel(chip, instr->opcode, idx, true))
+         return 2;
+      if (instr->format == Format::VOP3P)
+         return 2;
    }
 
    switch (instr->opcode) {
+   case aco_opcode::v_cvt_f32_ubyte0: return 1;
    case aco_opcode::ds_write_b8:
    case aco_opcode::ds_write_b16: return chip >= GFX8 ? 2 : 4;
    case aco_opcode::buffer_store_byte:
@@ -489,10 +494,8 @@ get_subdword_operand_stride(chip_class chip, const aco_ptr<Instruction>& instr,
    case aco_opcode::scratch_store_short:
    case aco_opcode::global_store_byte:
    case aco_opcode::global_store_short: return chip >= GFX9 ? 2 : 4;
-   default: break;
+   default: return 4;
    }
-
-   return 4;
 }
 
 void
@@ -504,58 +507,59 @@ add_subdword_operand(ra_ctx& ctx, aco_ptr<Instruction>& instr, unsigned idx, uns
       return;
 
    assert(rc.bytes() <= 2);
-
-   if (!instr->usesModifiers() && instr->opcode == aco_opcode::v_cvt_f32_ubyte0) {
-      switch (byte) {
-      case 0: instr->opcode = aco_opcode::v_cvt_f32_ubyte0; break;
-      case 1: instr->opcode = aco_opcode::v_cvt_f32_ubyte1; break;
-      case 2: instr->opcode = aco_opcode::v_cvt_f32_ubyte2; break;
-      case 3: instr->opcode = aco_opcode::v_cvt_f32_ubyte3; break;
+   if (instr->isVALU()) {
+      /* check if we can use opsel */
+      if (instr->format == Format::VOP3) {
+         assert(rc == v2b && byte == 2);
+         instr->vop3().opsel |= 1 << idx;
+         return;
       }
-      return;
-   } else if (can_use_SDWA(chip, instr, false)) {
-      aco_ptr<Instruction> tmp = convert_to_SDWA(chip, instr);
-      return;
-   } else if (rc.bytes() == 2 && can_use_opsel(chip, instr->opcode, idx, byte / 2)) {
-      instr->vop3().opsel |= (byte / 2) << idx;
-      return;
-   } else if (instr->isVOP3P() && byte == 2) {
-      VOP3P_instruction& vop3p = instr->vop3p();
-      assert(!(vop3p.opsel_lo & (1 << idx)));
-      vop3p.opsel_lo |= 1 << idx;
-      vop3p.opsel_hi |= 1 << idx;
+      if (instr->isVOP3P()) {
+         assert(rc == v2b && byte == 2 && !(instr->vop3p().opsel_lo & (1 << idx)));
+         instr->vop3p().opsel_lo |= 1 << idx;
+         instr->vop3p().opsel_hi |= 1 << idx;
+         return;
+      }
+      if (instr->opcode == aco_opcode::v_cvt_f32_ubyte0) {
+         switch (byte) {
+         case 0: instr->opcode = aco_opcode::v_cvt_f32_ubyte0; break;
+         case 1: instr->opcode = aco_opcode::v_cvt_f32_ubyte1; break;
+         case 2: instr->opcode = aco_opcode::v_cvt_f32_ubyte2; break;
+         case 3: instr->opcode = aco_opcode::v_cvt_f32_ubyte3; break;
+         }
+         return;
+      }
+
+      /* use SDWA */
+      assert(can_use_SDWA(chip, instr, false));
+      convert_to_SDWA(chip, instr);
       return;
    }
 
-   if (chip >= GFX8 && instr->opcode == aco_opcode::ds_write_b8 && byte == 2) {
+   assert(byte == 2);
+   if (instr->opcode == aco_opcode::ds_write_b8)
       instr->opcode = aco_opcode::ds_write_b8_d16_hi;
-      return;
-   }
-   if (chip >= GFX8 && instr->opcode == aco_opcode::ds_write_b16 && byte == 2) {
+   else if (instr->opcode == aco_opcode::ds_write_b16)
       instr->opcode = aco_opcode::ds_write_b16_d16_hi;
-      return;
-   }
-
-   if (chip >= GFX9 && byte == 2) {
-      if (instr->opcode == aco_opcode::buffer_store_byte)
-         instr->opcode = aco_opcode::buffer_store_byte_d16_hi;
-      else if (instr->opcode == aco_opcode::buffer_store_short)
-         instr->opcode = aco_opcode::buffer_store_short_d16_hi;
-      else if (instr->opcode == aco_opcode::flat_store_byte)
-         instr->opcode = aco_opcode::flat_store_byte_d16_hi;
-      else if (instr->opcode == aco_opcode::flat_store_short)
-         instr->opcode = aco_opcode::flat_store_short_d16_hi;
-      else if (instr->opcode == aco_opcode::scratch_store_byte)
-         instr->opcode = aco_opcode::scratch_store_byte_d16_hi;
-      else if (instr->opcode == aco_opcode::scratch_store_short)
-         instr->opcode = aco_opcode::scratch_store_short_d16_hi;
-      else if (instr->opcode == aco_opcode::global_store_byte)
-         instr->opcode = aco_opcode::global_store_byte_d16_hi;
-      else if (instr->opcode == aco_opcode::global_store_short)
-         instr->opcode = aco_opcode::global_store_short_d16_hi;
-      else
-         unreachable("Something went wrong: Impossible register assignment.");
-   }
+   else if (instr->opcode == aco_opcode::buffer_store_byte)
+      instr->opcode = aco_opcode::buffer_store_byte_d16_hi;
+   else if (instr->opcode == aco_opcode::buffer_store_short)
+      instr->opcode = aco_opcode::buffer_store_short_d16_hi;
+   else if (instr->opcode == aco_opcode::flat_store_byte)
+      instr->opcode = aco_opcode::flat_store_byte_d16_hi;
+   else if (instr->opcode == aco_opcode::flat_store_short)
+      instr->opcode = aco_opcode::flat_store_short_d16_hi;
+   else if (instr->opcode == aco_opcode::scratch_store_byte)
+      instr->opcode = aco_opcode::scratch_store_byte_d16_hi;
+   else if (instr->opcode == aco_opcode::scratch_store_short)
+      instr->opcode = aco_opcode::scratch_store_short_d16_hi;
+   else if (instr->opcode == aco_opcode::global_store_byte)
+      instr->opcode = aco_opcode::global_store_byte_d16_hi;
+   else if (instr->opcode == aco_opcode::global_store_short)
+      instr->opcode = aco_opcode::global_store_short_d16_hi;
+   else
+      unreachable("Something went wrong: Impossible register assignment.");
+   return;
 }
 
 /* minimum_stride, bytes_written */