# HLX ISA quick reference

The quick reference lists HLX instruction syntax grouped by instruction
category.

## [Halfword absolute value](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-absolute-value)

- Ld16.uh=abs(Lu16.h)
- Ld16.h=abs(Lu16.h):sat

## [Halfword and word add/subtract](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-and-word-add-subtract)

- Ldd16.w=add(Luu16.w,Lv16.h)
- Ldd16.w=add(Luu16.w,Lv16.uh)
- Ldd16.w=sub(Luu16.w,Lv16.h)
- Ldd16.w=sub(Luu16.w,Lv16.uh)

## [Halfword widening add/subtract](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-widening-add-subtract)

- Ldd16.w=add(Lu16.uh,Lv16.uh)
- Ldd16.w=sub(Lu16.uh,Lv16.uh)

## [Halfword add/subtract](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-add-subtract)

- Ld16.h=add(Lu16.h,Lv16.h)
- Ld16.h=add(Lu16.h,Lv16.h):sat
- Ld16.uh=add(Lu16.uh,Lv16.uh):sat
- Ld16.uh=add(Lu16.h,Lv16.h):sat
- Ld16.h=sub(Lu16.h,Lv16.h)
- Ld16.h=sub(Lu16.h,Lv16.h):sat
- Ld16.uh=sub(Lu16.uh,Lv16.uh):sat
- Ld16.uh=sub(Lu16.h,Lv16.h):sat

## [Assign](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-assign)

- Ld16.h=Lu16.h
- Ldd16.w=Luu16.w

## [Halfword compare](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-compare)

- Ld16.h=cmp.gt(Lu16.uh, Lv16.uh)
- Ld16.h=cmp.gt(Lu16.h, Lv16.h)

## [Halfword to word convert](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-to-word-convert)

- Ldd16.uw=zxt(Lu16.uh)
- Ldd16.w=sxt(Lu16.h)

## [Logical operations](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-logical-operations)

- Ld16=and(Lu16,Lv16)
- Ld16=or(Lu16,Lv16)
- Ld16=xor(Lu16,Lv16)
- Ld16=not(Lu16)
- Ld16=andn(Lu16,Lv16)
- Ld16=orn(Lu16,Lv16)

## [Halfword min/max](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-min-max)

- Ld16.uh=max(Lu16.uh,Lv16.uh)
- Ld16.uh=min(Lu16.uh,Lv16.uh)
- Ld16.h=max(Lu16.h,Lv16.h)
- Ld16.h=min(Lu16.h,Lv16.h)

## [Mux select](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-mux-select)

- Lx16.h=mux(Lx16.h,Lu16.h,Lv16.h)

## [Splat value](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-splat-value)

- Ld16.h=Rt.h
- Ld16.h=#s5
- Ld16.uh=#u5
- Ldd16.w=Rt.w

## [Absolute value of difference](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-absolute-value-of-difference)

- Ld16.uh=absdiff(Lu16.h,Lv16.h)
- Ld16.uh=absdiff(Lu16.uh,Lv16.uh)
- Ldd16.uw=absdiff(Luu16.w,Lvv16.w)
- Ldd16.uw=absdiff(Luu16.uw,Lvv16.uw)

## [Average](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-average)

- Ld16.h=avg(Lu16.h,Lv16.h)
- Ld16.h=avg(Lu16.h,Lv16.h):rnd
- Ldd16.w=avg(Luu16.w,Lvv16.w)
- Ldd16.w=avg(Luu16.w,Lvv16.w):rnd
- Ld16.uh=avg(Lu16.uh,Lv16.uh)
- Ld16.uh=avg(Lu16.uh,Lv16.uh):rnd
- Ldd16.uw=avg(Luu16.uw,Lvv16.uw)
- Ldd16.uw=avg(Luu16.uw,Lvv16.uw):rnd

## [Byte converts](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-byte-converts)

- Ld16.b=packhi(Lu16.h,Lv16.h)
- Ld16.b=packlo(Lu16.h,Lv16.h)
- Ldd16.h=unpackhi(Lu16.b)
- Ldd16.h=unpacklo(Lu16.b)

## [Bit counting](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-bit-counting)

- Ld16.h=sub(ilog2(Lu16.h),#u4)
- Ld16.h=sub(ilog2(Lu16.uh),#u4)
- Ld16.h=sub(ilog2(Luu16.w),#u5)
- Ld16.h=sub(ilog2(Luu16.uw),#u5)

## [Lookup table](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-lookup-table)

- Ld16.h=lut4(Lu16.uh,Rtt.h)
- Ldd16.w=lut4(Lu16.uh,Rtt.uh):>>1
- Ldd16.w=lut4(Lu16.uh,Rtt.uh):>>1:neg
- Ld16.h=lut4(Lu16.uh,Rtt.h):mask

## [Negative average](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-negative-average)

- Ld16.h=navg(Lu16.h,Lv16.h)
- Ldd16.w=navg(Luu16.w,Lvv16.w)
- Ld16.h=navg(Lu16.uh,Lv16.uh)
- Ldd16.w=navg(Luu16.uw,Lvv16.uw)

## [Load - tmp](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-load-tmp)

- Ld16.tmp=mem(Rs)
- if (Pv) Ld16.tmp=mem(Rs)
- Ld16.tmp=mem(Rx++#s3)
- if (Pv) Ld16.tmp=mem(Rx++#s3)
- Ld16.tmp=mem(Rx++Mu)
- if (Pv) Ld16.tmp=mem(Rx++Mu)

## [Multiply-add with high or low](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-multiply-add-with-high-or-low)

- Lxx16.uw=add(mpy(Lu16.uh,Rt.uh),lo(Lxx16).uh)
- Lxx16.uw=add(mpy(Lu16.uh,Lv16.uh),lo(Lxx16).uh)
- Lxx16.w=add(mpy(Lu16.h,Rt.uh),lo(Lxx16).uh)
- Lxx16.w=add(mpy(Lu16.h,Lv16.uh),lo(Lxx16).uh)
- Lxx16.uw=add(mpy(Lu16.uh,Rt.uh),hi(Lxx16).uh)
- Lxx16.uw=add(mpy(Lu16.uh,Lv16.uh),hi(Lxx16).uh)
- Lxx16.uw=add(mpy(Lu16.h,Rt.uh),hi(Lxx16).uh)
- Lxx16.uw=add(mpy(Lu16.h,Lv16.uh),hi(Lxx16).uh)
- Lxx16.uw=add(mpy(Lu16.uh,hi(Lxx16).uh),Rt.w)
- Lxx16.uw=add(mpy(Lu16.uh,hi(Lxx16).uh),Lvv16.w)
- Lxx16.w=add(mpy(Lu16.uh,hi(Lxx16).h),Rt.w)
- Lxx16.w=add(mpy(Lu16.uh,hi(Lxx16).h),Lvv16.w)

## [Multiply-add](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-multiply-add)

- Lxx16.w+=mpy(Lu16.uh,Rt.uh)
- Lxx16.w+=mpy(Lu16.uh,Lv16.uh)
- Lxx16.w+=mpy(Lu16.h,Rt.uh)
- Lxx16.w+=mpy(Lu16.h,Lv16.uh)
- Lxx16.w+=mpy(Lu16.h,Rt.h)
- Lxx16.w+=mpy(Lu16.h,Lv16.h)

## [Halfword to word multiply](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-to-word-multiply)

- Ldd16.uw=mpy(Lu16.uh,Rt.uh)
- Ldd16.uw=mpy(Lu16.uh,Lv16.uh)
- Ldd16.w=mpy(Lu16.h,Rt.uh)
- Ldd16.w=mpy(Lu16.h,Lv16.uh)
- Ldd16.w=mpy(Lu16.h,Rt.h)
- Ldd16.w=mpy(Lu16.h,Lv16.h)

## [Paired and word absolute value](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-paired-and-word-absolute-value)

- Ldd16.uw=abs(Luu16.w)
- Ldd16.w=abs(Luu16.w):sat
- Ldd16.uh=abs(Luu16.h)
- Ldd16.h=abs(Luu16.h):sat

## [Paired halfword add/subtract](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-paired-halfword-add-subtract)

- Ldd16.h=add(Luu16.h,Lvv16.h)
- Ldd16.h=add(Luu16.h,Lvv16.h):sat
- Ldd16.uh=add(Luu16.uh,Lvv16.uh):sat
- Ldd16.uh=add(Luu16.h,Lvv16.h):sat
- Ldd16.h=sub(Luu16.h,Lvv16.h)
- Ldd16.h=sub(Luu16.h,Lvv16.h):sat
- Ldd16.uh=sub(Luu16.uh,Lvv16.uh):sat
- Ldd16.uh=sub(Luu16.h,Lvv16.h):sat

## [Word add/subtract](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-word-add-subtract)

- Ldd16.w=add(Luu16.w,Lvv16.w)
- Ldd16.w=add(Luu16.w,Lvv16.w):sat
- Ldd16.uw=add(Luu16.uw,Lvv16.uw):sat
- Ldd16.uw=add(Luu16.w,Lvv16.w):sat
- Ldd16.w=sub(Luu16.w,Lvv16.w)
- Ldd16.w=sub(Luu16.w,Lvv16.w):sat
- Ldd16.uw=sub(Luu16.uw,Lvv16.uw):sat
- Ldd16.uw=sub(Luu16.w,Lvv16.w):sat

## [Word logical operations](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-word-logical-operations)

- Ldd16=and(Luu16,Lvv16)
- Ldd16=or(Luu16,Lvv16)
- Ldd16=xor(Luu16,Lvv16)
- Ldd16=andn(Luu16,Lvv16)
- Ldd16=orn(Luu16,Lvv16)
- Ldd16=not(Luu16)

## [Paired halfword logical compare](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-paired-halfword-logical-compare)

- Ldd16.h=cmp.gt(Luu16.h, Lvv16.h)
- Ldd16.h=cmp.gt(Luu16.uh, Lvv16.uh)

## [Word compare](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-word-compare)

- Ldd16.w=cmp.gt(Luu16.w, Lvv16.w)
- Ldd16.w=cmp.gt(Luu16.uw, Lvv16.uw)

## [Combine](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-combine)

- Ldd16=combine(Lu16,Lv16)

## [Word min/max](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-word-min-max)

- Ldd16.w=min(Luu16.w,Lvv16.w)
- Ldd16.uw=min(Luu16.uw,Lvv16.uw)
- Ldd16.w=max(Luu16.w,Lvv16.w)
- Ldd16.uw=max(Luu16.uw,Lvv16.uw)

## [Paired halfword min/max](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-paired-halfword-min-max)

- Ldd16.h=min(Luu16.h,Lvv16.h)
- Ldd16.uh=min(Luu16.uh,Lvv16.uh)
- Ldd16.h=max(Luu16.h,Lvv16.h)
- Ldd16.uh=max(Luu16.uh,Lvv16.uh)

## [Halfword bidirectional shift](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-bidirectional-shift)

- Ld16.uh=shr(Lu16.uh,Lv16.h)
- Ld16.uh=shr(Lu16.uh,Rt.h)
- Ld16.h=shr(Lu16.h,Lv16.h)
- Ld16.h=shr(Lu16.h,Rt.h)

## [Word to halfword narrowing bidirectional shift](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-word-to-halfword-narrowing-bidirectional-shift)

- Ld16.h=shr(Luu16.w,Lv16.h):sat
- Ld16.h=shr(Luu16.w,Lv16.h):rnd:sat
- Ld16.h=shr(Luu16.w,Rt.h):sat
- Ld16.h=shr(Luu16.w,Rt.h):rnd:sat
- Ld16.uh=shr(Luu16.uw,Lv16.h):sat
- Ld16.uh=shr(Luu16.uw,Lv16.h):rnd:sat
- Ld16.uh=shr(Luu16.uw,Rt.h):sat
- Ld16.uh=shr(Luu16.uw,Rt.h):rnd:sat
- Ld16.uh=shr(Luu16.w,Lv16.h):sat
- Ld16.uh=shr(Luu16.w,Lv16.h):rnd:sat
- Ld16.uh=shr(Luu16.w,Rt.h):sat
- Ld16.uh=shr(Luu16.w,Rt.h):rnd:sat

## [Word bidirectional shift](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-word-bidirectional-shift)

- Ldd16.uw=shr(Luu16.uw,Lv16.h)
- Ldd16.uw=shr(Luu16.uw,Rt.h)
- Ldd16.w=shr(Luu16.w,Lv16.h)
- Ldd16.w=shr(Luu16.w,Rt.h)

## [Word to halfword narrowing right shift](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-word-to-halfword-narrowing-right-shift)

- Ld16.h=shr(Luu16.w,Lv16.uh)
- Ld16.h=shr(Luu16.w,Rt.uh)

## [Halfword bidirectional shift add](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-halfword-bidirectional-shift-add)

- Lx16.h+=shr(Lu16.uh,Lv16.h)
- Lx16.h+=shr(Lu16.uh,Rt.h)
- Lx16.h+=shr(Lu16.h,Lv16.h)
- Lx16.h+=shr(Lu16.h,Rt.h)

## [Word bidirectional shift add](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-word-bidirectional-shift-add)

- Lxx16.w+=shr(Luu16.uw,Lv16.h)
- Lxx16.w+=shr(Luu16.uw,Rt.h)
- Lxx16.w+=shr(Luu16.w,Lv16.h)
- Lxx16.w+=shr(Luu16.w,Rt.h)

## [Store - new](https://docs.qualcomm.com/doc/80-N3040-23/topic/hlx-instruction-set.html#v85-hlx-store-new)

- mem(Rs)=Ku16.new
- if (Pv) mem(Rs)=Ku16.new
- mem(Rx++#s3)=Ku16.new
- if (Pv) mem(Rx++#s3)=Ku16.new
- mem(Rx++Mu)=Kt16.new
- if (Pv) mem(Rx++Mu)=Kt16.new

Last Published: Oct 06, 2026

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