diff --git a/src/etnaviv/isa/asm.h b/src/etnaviv/isa/asm.h
index a467b0e091b..6f7df8799aa 100644
--- a/src/etnaviv/isa/asm.h
+++ b/src/etnaviv/isa/asm.h
@@ -79,11 +79,10 @@ struct etna_inst {
    enum isa_opc opcode;
    enum isa_type type;
    enum isa_rounding rounding;
-   enum isa_cond cond : 5;
-   unsigned sat       : 1;                 /* saturate result between 0..1 */
-   unsigned sel_bit0  : 1;                 /* select low half mediump */
-   unsigned sel_bit1  : 1;                 /* select high half mediump */
-   unsigned dst_full  : 1;                 /* write to highp register */
+   enum isa_cond cond     : 5;
+   unsigned sat           : 1;             /* saturate result between 0..1 */
+   enum isa_thread thread : 2;             /* select low/high half mediump */
+   unsigned dst_full      : 1;             /* write to highp register */
    struct etna_inst_dst dst;               /* destination operand */
    struct etna_inst_tex tex;               /* texture operand */
    struct etna_inst_src src[ETNA_NUM_SRC]; /* source operand */
diff --git a/src/etnaviv/isa/etnaviv.xml b/src/etnaviv/isa/etnaviv.xml
index 8b2d7e0a8e1..ad2d8dbf094 100644
--- a/src/etnaviv/isa/etnaviv.xml
+++ b/src/etnaviv/isa/etnaviv.xml
@@ -148,8 +148,8 @@ SPDX-License-Identifier: MIT
 	<encode type="struct etna_inst *" case-prefix="ISA_OPC_">
 		<map name="TYPE_BIT01">src->type &amp; 0x3</map>
 		<map name="TYPE_BIT2">(src->type &amp; 0x4) &gt; 2</map>
-		<map name="LOW_HALF">src->sel_bit0</map>
-		<map name="HIGH_HALF">src->sel_bit1</map>
+		<map name="LOW_HALF">(src->thread &amp; 0x1)</map>
+		<map name="HIGH_HALF">(src->thread &amp; 0x2) &gt; 1</map>
 		<map name="COND">src->cond</map>
 		<map name="RMODE">src->rounding</map>
 		<map name="SAT">src->sat</map>