Syntax of AMDGPU Instruction Modifiers

Conventions

The following notation is used throughout this document:

Notation

Description

{0..N}

Any integer value in the range from 0 to N (inclusive).

<x>

Syntax and meaning of x are explained elsewhere.

Modifiers

DS Modifiers

offset0

Specifies the first 8-bit offset, in bytes. The default value is 0.

Used with DS instructions that expect two addresses.

Syntax

Description

offset0:{0..0xFF}

Specifies an unsigned 8-bit offset as a positive integer number or an absolute expression.

Examples:

offset0:0xff
offset0:2-x
offset0:-x-y

offset1

Specifies the second 8-bit offset, in bytes. The default value is 0.

Used with DS instructions that expect two addresses.

Syntax

Description

offset1:{0..0xFF}

Specifies an unsigned 8-bit offset as a positive integer number or an absolute expression.

Examples:

offset1:0xff
offset1:2-x
offset1:-x-y

offset

Specifies a 16-bit offset, in bytes. The default value is 0.

Used with DS instructions that expect a single address.

Syntax

Description

offset:{0..0xFFFF}

Specifies an unsigned 16-bit offset as a positive integer number or an absolute expression.

Examples:

offset:65535
offset:0xffff
offset:-x-y

swizzle pattern

This is a special modifier that may be used with ds_swizzle_b32 instruction only. It specifies a swizzle pattern in numeric or symbolic form. The default value is 0.

Syntax

Description

offset:{0..0xFFFF}

Specifies a 16-bit swizzle pattern.

offset:swizzle(QUAD_PERM,{0..3},{0..3},{0..3},{0..3})

Specifies a quad permute mode pattern

Each number is a lane id.

offset:swizzle(BITMASK_PERM, “<mask>”)

Specifies a bitmask permute mode pattern.

The pattern converts a 5-bit lane id to another lane id with which the lane interacts.

The mask is a 5-character sequence which specifies how to transform the bits of the lane id.

The following characters are allowed:

  • “0” - set bit to 0.

  • “1” - set bit to 1.

  • “p” - preserve bit.

  • “i” - inverse bit.

offset:swizzle(BROADCAST,{2..32},{0..N})

Specifies a broadcast mode.

Broadcasts the value of any particular lane to all lanes in its group.

The first numeric parameter is a group size and must be equal to 2, 4, 8, 16 or 32.

The second numeric parameter is an index of the lane being broadcast.

The index must not exceed group size.

offset:swizzle(SWAP,{1..16})

Specifies a swap mode.

Swaps the neighboring groups of 1, 2, 4, 8 or 16 lanes.

offset:swizzle(REVERSE,{2..32})

Specifies a reverse mode.

Reverses the lanes for groups of 2, 4, 8, 16 or 32 lanes.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

offset:255
offset:0xffff
offset:swizzle(QUAD_PERM, 0, 1, 2, 3)
offset:swizzle(BITMASK_PERM, "01pi0")
offset:swizzle(BROADCAST, 2, 0)
offset:swizzle(SWAP, 8)
offset:swizzle(REVERSE, 30 + 2)

gds

Specifies whether to use GDS or LDS memory (LDS is the default).

Syntax

Description

gds

Use GDS memory.

EXP Modifiers

done

Specifies if this is the last export from the shader to the target. By default, an export instruction does not finish an export sequence.

Syntax

Description

done

Indicates the last export operation.

compr

Indicates if the data is compressed (data is not compressed by default).

Syntax

Description

compr

Data is compressed.

vm

Specifies if the exec mask is valid for this export instruction (the mask is not valid by default).

Syntax

Description

vm

Set the flag indicating a valid exec mask.

row_en

Specifies whether to export one row or multiple rows of data.

Syntax

Description

row_en

Export multiple rows using row index from M0.

FLAT Modifiers

offset12

Specifies an immediate unsigned 12-bit offset, in bytes. The default value is 0.

Syntax

Description

offset:{0..4095}

Specifies a 12-bit unsigned offset as a positive integer number or an absolute expression.

Examples:

offset:4095
offset:x-0xff

offset13s

Specifies an immediate signed 13-bit offset, in bytes. The default value is 0.

Syntax

Description

offset:{-4096..4095}

Specifies a 13-bit signed offset as an integer number or an absolute expression.

Examples:

offset:-4000
offset:0x10
offset:-x

offset12s

Specifies an immediate signed 12-bit offset, in bytes. The default value is 0.

Syntax

Description

offset:{-2048..2047}

Specifies a 12-bit signed offset as an integer number or an absolute expression.

Examples:

offset:-2000
offset:0x10
offset:-x+y

offset11

Specifies an immediate unsigned 11-bit offset, in bytes. The default value is 0.

Syntax

Description

offset:{0..2047}

Specifies an 11-bit unsigned offset as a positive integer number or an absolute expression.

Examples:

offset:2047
offset:x+0xff

dlc

See a description here.

glc

See a description here.

lds

See a description here.

slc

See a description here.

tfe

See a description here.

nv

See a description here.

sc0

See a description here.

sc1

See a description here.

nt

See a description here.

MIMG Modifiers

dmask

Specifies which channels (image components) are used by the operation. By default, no channels are used.

Syntax

Description

dmask:{0..15}

Specifies image channels as a positive integer number or an absolute expression.

Each bit corresponds to one of 4 image components (RGBA).

If the specified bit value is 0, the image component is not used, while value 1 means that the component is used.

This modifier has some limitations depending on the instruction kind:

Instruction Kind

Valid dmask Values

32-bit atomic cmpswap

0x3

32-bit atomic instructions except for cmpswap

0x1

64-bit atomic cmpswap

0xF

64-bit atomic instructions except for cmpswap

0x3

gather4

0x1, 0x2, 0x4, 0x8

GFX11+ msaa_load

0x1, 0x2, 0x4, 0x8

Other instructions

any value

Examples:

dmask:0xf
dmask:0b1111
dmask:x|y|z

unorm

Specifies whether the address is normalized or not (the address is normalized by default).

Syntax

Description

unorm

Force the address to be not normalized.

glc

See a description here.

slc

See a description here.

r128

Specifies texture resource size. The default size is 256 bits.

Syntax

Description

r128

Specifies 128 bits texture resource size.

Warning

Using this modifier shall decrease rsrc operand size from 8 to 4 dwords, but assembler does not currently support this feature.

tfe

See a description here.

lwe

Specifies LOD warning status (LOD warning is disabled by default).

Syntax

Description

lwe

Enables LOD warning.

da

Specifies if an array index must be sent to TA. By default, the array index is not sent.

Syntax

Description

da

Send an array index to TA.

d16

Specifies data size: 16 or 32 bits (32 bits by default).

Syntax

Description

d16

Enables 16-bits data mode.

On loads, convert data in memory to 16-bit format before storing it in VGPRs.

For stores, convert 16-bit data in VGPRs to 32 bits before writing the values to memory.

Note that GFX8.0 does not support data packing. Each 16-bit data element occupies 1 VGPR.

GFX8.1 and GFX9+ support data packing. Each pair of 16-bit data elements occupies 1 VGPR.

a16

Specifies the size of image address components: 16 or 32 bits (32 bits by default).

Syntax

Description

a16

Enables 16-bits image address components.

dim

Specifies surface dimension. This is a mandatory modifier. There is no default value.

Syntax

Description

dim:1D

One-dimensional image.

dim:2D

Two-dimensional image.

dim:3D

Three-dimensional image.

dim:CUBE

Cubemap array.

dim:1D_ARRAY

One-dimensional image array.

dim:2D_ARRAY

Two-dimensional image array.

dim:2D_MSAA

Two-dimensional multi-sample auto-aliasing image.

dim:2D_MSAA_ARRAY

Two-dimensional multi-sample auto-aliasing image array.

The following table defines an alternative syntax which is supported for compatibility with SP3 assembler:

Syntax

Description

dim:SQ_RSRC_IMG_1D

One-dimensional image.

dim:SQ_RSRC_IMG_2D

Two-dimensional image.

dim:SQ_RSRC_IMG_3D

Three-dimensional image.

dim:SQ_RSRC_IMG_CUBE

Cubemap array.

dim:SQ_RSRC_IMG_1D_ARRAY

One-dimensional image array.

dim:SQ_RSRC_IMG_2D_ARRAY

Two-dimensional image array.

dim:SQ_RSRC_IMG_2D_MSAA

Two-dimensional multi-sample auto-aliasing image.

dim:SQ_RSRC_IMG_2D_MSAA_ARRAY

Two-dimensional multi-sample auto-aliasing image array.

dlc

See a description here.

Miscellaneous Modifiers

dlc

Controls device level cache policy for memory operations. Used for synchronization. When specified, forces operation to bypass device level cache, making the operation device level coherent. By default, instructions use device level cache.

Syntax

Description

dlc

Bypass device level cache.

glc

For atomic opcodes, this modifier indicates that the instruction returns the value from memory before the operation. For other opcodes, it is used together with slc to specify cache policy.

The default value is off (0).

Syntax

Description

glc

Set glc bit to 1.

lds

Specifies where to store the result: VGPRs or LDS (VGPRs by default).

Syntax

Description

lds

Store the result in LDS.

nv

Specifies if the instruction is operating on non-volatile memory. By default, memory is volatile.

Syntax

Description

nv

Indicates that the instruction operates on non-volatile memory.

slc

Controls behavior of L2 cache. The default value is off (0).

Syntax

Description

slc

Set slc bit to 1.

tfe

Controls access to partially resident textures. The default value is off (0).

Syntax

Description

tfe

Set tfe bit to 1.

sc0

For atomic opcodes, this modifier indicates that the instruction returns the value from memory before the operation. For other opcodes, it is used together with sc1 to specify cache policy.

Syntax

Description

sc0

Set sc0 bit to 1.

sc1

This modifier is used together with sc0 to specify cache policy.

Syntax

Description

sc1

Set sc1 bit to 1.

nt

Indicates an operation with non-temporal data.

Syntax

Description

nt

Set nt bit to 1.

MUBUF/MTBUF Modifiers

idxen

Specifies whether address components include an index. By default, the index is not used.

May be used together with offen.

Cannot be used with addr64.

Syntax

Description

idxen

Address components include an index.

offen

Specifies whether address components include an offset. By default, the offset is not used.

May be used together with idxen.

Cannot be used with addr64.

Syntax

Description

offen

Address components include an offset.

addr64

Specifies whether a 64-bit address is used. By default, no address is used.

Cannot be used with offen and idxen modifiers.

Syntax

Description

addr64

A 64-bit address is used.

offset12

Specifies an immediate unsigned 12-bit offset, in bytes. The default value is 0.

Syntax

Description

offset:{0..0xFFF}

Specifies a 12-bit unsigned offset as a positive integer number or an absolute expression.

Examples:

offset:x+y
offset:0x10

glc

See a description here.

slc

See a description here.

lds

See a description here.

dlc

See a description here.

tfe

See a description here.

fmt

Specifies data and numeric formats used by the operation. The default numeric format is BUF_NUM_FORMAT_UNORM. The default data format is BUF_DATA_FORMAT_8.

Syntax

Description

format:{0..127}

Use a format specified as either an integer number or an absolute expression.

format:[<data format>]

Use the specified data format and default numeric format.

format:[<numeric format>]

Use the specified numeric format and default data format.

format:[<data format>,<numeric format>]

Use the specified data and numeric formats.

format:[<numeric format>,<data format>]

Use the specified data and numeric formats.

Supported data formats are defined in the following table:

Syntax

Note

BUF_DATA_FORMAT_INVALID

BUF_DATA_FORMAT_8

The default value.

BUF_DATA_FORMAT_16

BUF_DATA_FORMAT_8_8

BUF_DATA_FORMAT_32

BUF_DATA_FORMAT_16_16

BUF_DATA_FORMAT_10_11_11

BUF_DATA_FORMAT_11_11_10

BUF_DATA_FORMAT_10_10_10_2

BUF_DATA_FORMAT_2_10_10_10

BUF_DATA_FORMAT_8_8_8_8

BUF_DATA_FORMAT_32_32

BUF_DATA_FORMAT_16_16_16_16

BUF_DATA_FORMAT_32_32_32

BUF_DATA_FORMAT_32_32_32_32

BUF_DATA_FORMAT_RESERVED_15

Supported numeric formats are defined below:

Syntax

Note

BUF_NUM_FORMAT_UNORM

The default value.

BUF_NUM_FORMAT_SNORM

BUF_NUM_FORMAT_USCALED

BUF_NUM_FORMAT_SSCALED

BUF_NUM_FORMAT_UINT

BUF_NUM_FORMAT_SINT

BUF_NUM_FORMAT_SNORM_OGL

GFX7 only.

BUF_NUM_FORMAT_RESERVED_6

GFX8 and GFX9 only.

BUF_NUM_FORMAT_FLOAT

Examples:

format:0
format:127
format:[BUF_DATA_FORMAT_16]
format:[BUF_DATA_FORMAT_16,BUF_NUM_FORMAT_SSCALED]
format:[BUF_NUM_FORMAT_FLOAT]

ufmt

Specifies a unified format used by the operation. The default format is BUF_FMT_8_UNORM.

Syntax

Description

format:{0..127}

Use a unified format specified as either an integer number or an absolute expression. Note that unified format numbers are incompatible with format numbers used for pre-GFX10 ISA.

format:[<unified format>]

Use the specified unified format.

Unified format is a replacement for data and numeric formats. For compatibility with older ISA, the syntax with data and numeric formats is still accepted provided that the combination of formats can be mapped to a unified format.

Supported unified formats and equivalent combinations of data and numeric formats are defined below:

Unified Format Syntax

Equivalent Data Format

Equivalent Numeric Format

Note

BUF_FMT_INVALID

BUF_DATA_FORMAT_INVALID

BUF_NUM_FORMAT_UNORM

BUF_FMT_8_UNORM

BUF_DATA_FORMAT_8

BUF_NUM_FORMAT_UNORM

BUF_FMT_8_SNORM

BUF_DATA_FORMAT_8

BUF_NUM_FORMAT_SNORM

BUF_FMT_8_USCALED

BUF_DATA_FORMAT_8

BUF_NUM_FORMAT_USCALED

BUF_FMT_8_SSCALED

BUF_DATA_FORMAT_8

BUF_NUM_FORMAT_SSCALED

BUF_FMT_8_UINT

BUF_DATA_FORMAT_8

BUF_NUM_FORMAT_UINT

BUF_FMT_8_SINT

BUF_DATA_FORMAT_8

BUF_NUM_FORMAT_SINT

BUF_FMT_16_UNORM

BUF_DATA_FORMAT_16

BUF_NUM_FORMAT_UNORM

BUF_FMT_16_SNORM

BUF_DATA_FORMAT_16

BUF_NUM_FORMAT_SNORM

BUF_FMT_16_USCALED

BUF_DATA_FORMAT_16

BUF_NUM_FORMAT_USCALED

BUF_FMT_16_SSCALED

BUF_DATA_FORMAT_16

BUF_NUM_FORMAT_SSCALED

BUF_FMT_16_UINT

BUF_DATA_FORMAT_16

BUF_NUM_FORMAT_UINT

BUF_FMT_16_SINT

BUF_DATA_FORMAT_16

BUF_NUM_FORMAT_SINT

BUF_FMT_16_FLOAT

BUF_DATA_FORMAT_16

BUF_NUM_FORMAT_FLOAT

BUF_FMT_8_8_UNORM

BUF_DATA_FORMAT_8_8

BUF_NUM_FORMAT_UNORM

BUF_FMT_8_8_SNORM

BUF_DATA_FORMAT_8_8

BUF_NUM_FORMAT_SNORM

BUF_FMT_8_8_USCALED

BUF_DATA_FORMAT_8_8

BUF_NUM_FORMAT_USCALED

BUF_FMT_8_8_SSCALED

BUF_DATA_FORMAT_8_8

BUF_NUM_FORMAT_SSCALED

BUF_FMT_8_8_UINT

BUF_DATA_FORMAT_8_8

BUF_NUM_FORMAT_UINT

BUF_FMT_8_8_SINT

BUF_DATA_FORMAT_8_8

BUF_NUM_FORMAT_SINT

BUF_FMT_32_UINT

BUF_DATA_FORMAT_32

BUF_NUM_FORMAT_UINT

BUF_FMT_32_SINT

BUF_DATA_FORMAT_32

BUF_NUM_FORMAT_SINT

BUF_FMT_32_FLOAT

BUF_DATA_FORMAT_32

BUF_NUM_FORMAT_FLOAT

BUF_FMT_16_16_UNORM

BUF_DATA_FORMAT_16_16

BUF_NUM_FORMAT_UNORM

BUF_FMT_16_16_SNORM

BUF_DATA_FORMAT_16_16

BUF_NUM_FORMAT_SNORM

BUF_FMT_16_16_USCALED

BUF_DATA_FORMAT_16_16

BUF_NUM_FORMAT_USCALED

BUF_FMT_16_16_SSCALED

BUF_DATA_FORMAT_16_16

BUF_NUM_FORMAT_SSCALED

BUF_FMT_16_16_UINT

BUF_DATA_FORMAT_16_16

BUF_NUM_FORMAT_UINT

BUF_FMT_16_16_SINT

BUF_DATA_FORMAT_16_16

BUF_NUM_FORMAT_SINT

BUF_FMT_16_16_FLOAT

BUF_DATA_FORMAT_16_16

BUF_NUM_FORMAT_FLOAT

BUF_FMT_10_11_11_UNORM

BUF_DATA_FORMAT_10_11_11

BUF_NUM_FORMAT_UNORM

GFX10 only

BUF_FMT_10_11_11_SNORM

BUF_DATA_FORMAT_10_11_11

BUF_NUM_FORMAT_SNORM

GFX10 only

BUF_FMT_10_11_11_USCALED

BUF_DATA_FORMAT_10_11_11

BUF_NUM_FORMAT_USCALED

GFX10 only

BUF_FMT_10_11_11_SSCALED

BUF_DATA_FORMAT_10_11_11

BUF_NUM_FORMAT_SSCALED

GFX10 only

BUF_FMT_10_11_11_UINT

BUF_DATA_FORMAT_10_11_11

BUF_NUM_FORMAT_UINT

GFX10 only

BUF_FMT_10_11_11_SINT

BUF_DATA_FORMAT_10_11_11

BUF_NUM_FORMAT_SINT

GFX10 only

BUF_FMT_10_11_11_FLOAT

BUF_DATA_FORMAT_10_11_11

BUF_NUM_FORMAT_FLOAT

BUF_FMT_11_11_10_UNORM

BUF_DATA_FORMAT_11_11_10

BUF_NUM_FORMAT_UNORM

GFX10 only

BUF_FMT_11_11_10_SNORM

BUF_DATA_FORMAT_11_11_10

BUF_NUM_FORMAT_SNORM

GFX10 only

BUF_FMT_11_11_10_USCALED

BUF_DATA_FORMAT_11_11_10

BUF_NUM_FORMAT_USCALED

GFX10 only

BUF_FMT_11_11_10_SSCALED

BUF_DATA_FORMAT_11_11_10

BUF_NUM_FORMAT_SSCALED

GFX10 only

BUF_FMT_11_11_10_UINT

BUF_DATA_FORMAT_11_11_10

BUF_NUM_FORMAT_UINT

GFX10 only

BUF_FMT_11_11_10_SINT

BUF_DATA_FORMAT_11_11_10

BUF_NUM_FORMAT_SINT

GFX10 only

BUF_FMT_11_11_10_FLOAT

BUF_DATA_FORMAT_11_11_10

BUF_NUM_FORMAT_FLOAT

BUF_FMT_10_10_10_2_UNORM

BUF_DATA_FORMAT_10_10_10_2

BUF_NUM_FORMAT_UNORM

BUF_FMT_10_10_10_2_SNORM

BUF_DATA_FORMAT_10_10_10_2

BUF_NUM_FORMAT_SNORM

BUF_FMT_10_10_10_2_USCALED

BUF_DATA_FORMAT_10_10_10_2

BUF_NUM_FORMAT_USCALED

GFX10 only

BUF_FMT_10_10_10_2_SSCALED

BUF_DATA_FORMAT_10_10_10_2

BUF_NUM_FORMAT_SSCALED

GFX10 only

BUF_FMT_10_10_10_2_UINT

BUF_DATA_FORMAT_10_10_10_2

BUF_NUM_FORMAT_UINT

BUF_FMT_10_10_10_2_SINT

BUF_DATA_FORMAT_10_10_10_2

BUF_NUM_FORMAT_SINT

BUF_FMT_2_10_10_10_UNORM

BUF_DATA_FORMAT_2_10_10_10

BUF_NUM_FORMAT_UNORM

BUF_FMT_2_10_10_10_SNORM

BUF_DATA_FORMAT_2_10_10_10

BUF_NUM_FORMAT_SNORM

BUF_FMT_2_10_10_10_USCALED

BUF_DATA_FORMAT_2_10_10_10

BUF_NUM_FORMAT_USCALED

BUF_FMT_2_10_10_10_SSCALED

BUF_DATA_FORMAT_2_10_10_10

BUF_NUM_FORMAT_SSCALED

BUF_FMT_2_10_10_10_UINT

BUF_DATA_FORMAT_2_10_10_10

BUF_NUM_FORMAT_UINT

BUF_FMT_2_10_10_10_SINT

BUF_DATA_FORMAT_2_10_10_10

BUF_NUM_FORMAT_SINT

BUF_FMT_8_8_8_8_UNORM

BUF_DATA_FORMAT_8_8_8_8

BUF_NUM_FORMAT_UNORM

BUF_FMT_8_8_8_8_SNORM

BUF_DATA_FORMAT_8_8_8_8

BUF_NUM_FORMAT_SNORM

BUF_FMT_8_8_8_8_USCALED

BUF_DATA_FORMAT_8_8_8_8

BUF_NUM_FORMAT_USCALED

BUF_FMT_8_8_8_8_SSCALED

BUF_DATA_FORMAT_8_8_8_8

BUF_NUM_FORMAT_SSCALED

BUF_FMT_8_8_8_8_UINT

BUF_DATA_FORMAT_8_8_8_8

BUF_NUM_FORMAT_UINT

BUF_FMT_8_8_8_8_SINT

BUF_DATA_FORMAT_8_8_8_8

BUF_NUM_FORMAT_SINT

BUF_FMT_32_32_UINT

BUF_DATA_FORMAT_32_32

BUF_NUM_FORMAT_UINT

BUF_FMT_32_32_SINT

BUF_DATA_FORMAT_32_32

BUF_NUM_FORMAT_SINT

BUF_FMT_32_32_FLOAT

BUF_DATA_FORMAT_32_32

BUF_NUM_FORMAT_FLOAT

BUF_FMT_16_16_16_16_UNORM

BUF_DATA_FORMAT_16_16_16_16

BUF_NUM_FORMAT_UNORM

BUF_FMT_16_16_16_16_SNORM

BUF_DATA_FORMAT_16_16_16_16

BUF_NUM_FORMAT_SNORM

BUF_FMT_16_16_16_16_USCALED

BUF_DATA_FORMAT_16_16_16_16

BUF_NUM_FORMAT_USCALED

BUF_FMT_16_16_16_16_SSCALED

BUF_DATA_FORMAT_16_16_16_16

BUF_NUM_FORMAT_SSCALED

BUF_FMT_16_16_16_16_UINT

BUF_DATA_FORMAT_16_16_16_16

BUF_NUM_FORMAT_UINT

BUF_FMT_16_16_16_16_SINT

BUF_DATA_FORMAT_16_16_16_16

BUF_NUM_FORMAT_SINT

BUF_FMT_16_16_16_16_FLOAT

BUF_DATA_FORMAT_16_16_16_16

BUF_NUM_FORMAT_FLOAT

BUF_FMT_32_32_32_UINT

BUF_DATA_FORMAT_32_32_32

BUF_NUM_FORMAT_UINT

BUF_FMT_32_32_32_SINT

BUF_DATA_FORMAT_32_32_32

BUF_NUM_FORMAT_SINT

BUF_FMT_32_32_32_FLOAT

BUF_DATA_FORMAT_32_32_32

BUF_NUM_FORMAT_FLOAT

BUF_FMT_32_32_32_32_UINT

BUF_DATA_FORMAT_32_32_32_32

BUF_NUM_FORMAT_UINT

BUF_FMT_32_32_32_32_SINT

BUF_DATA_FORMAT_32_32_32_32

BUF_NUM_FORMAT_SINT

BUF_FMT_32_32_32_32_FLOAT

BUF_DATA_FORMAT_32_32_32_32

BUF_NUM_FORMAT_FLOAT

Examples:

format:0
format:[BUF_FMT_32_UINT]

SMRD/SMEM Modifiers

glc

See a description here.

nv

See a description here.

dlc

See a description here.

offset20u

Specifies an unsigned 20-bit offset, in bytes. The default value is 0.

Syntax

Description

offset:{0..0xFFFFF}

Specifies an offset as a positive integer number or an absolute expression.

Examples:

offset:1
offset:0xfffff
offset:x-y

offset21s

Specifies a signed 21-bit offset, in bytes. The default value is 0.

Syntax

Description

offset:{-0x100000..0xFFFFF}

Specifies an offset as an integer number or an absolute expression.

Examples:

offset:-1
offset:0xfffff
offset:-x

VINTRP/VINTERP/LDSDIR Modifiers

high

Specifies which half of the LDS word to use. Low half of LDS word is used by default.

Syntax

Description

high

Use the high half of LDS word.

neg

See a description here.

wait_exp

Specifies a wait on the EXP counter before issuing the current instruction. The counter must be less than or equal to this value before the instruction is issued. If set to 7, no wait is performed.

The default value is zero. This is a safe value, but it may be suboptimal.

Syntax

Description

wait_exp:{0..7}

An additional wait on the EXP counter before issuing this instruction.

wait_vdst

Specifies a wait on the VA_VDST counter before issuing the current instruction. The counter must be less than or equal to this value before the instruction is issued. If set to 15, no wait is performed.

The default value is zero. This is a safe value, but it may be suboptimal.

Syntax

Description

wait_vdst:{0..15}

An additional wait on the VA_VDST counter before issuing this instruction.

DPP8 Modifiers

dpp8_sel

Selects which lanes to pull data from, within a group of 8 lanes. This is a mandatory modifier. There is no default value.

The dpp8_sel modifier must specify exactly 8 values. The first value selects which lane to read from to supply data into lane 0. The second value controls lane 1 and so on.

Each value may be specified as either an integer number or an absolute expression.

Syntax

Description

dpp8:[{0..7},{0..7},{0..7},{0..7},{0..7},{0..7},{0..7},{0..7}]

Select lanes to read from.

Examples:

dpp8:[7,6,5,4,3,2,1,0]
dpp8:[0,1,0,1,0,1,0,1]

fi

Controls interaction with inactive lanes for dpp8 instructions. The default value is zero.

Note: inactive lanes are those whose exec mask bit is zero.

Syntax

Description

fi:0

Fetch zero when accessing data from inactive lanes.

fi:1

Fetch pre-existing values from inactive lanes.

Note: numeric values may be specified as either integer numbers or absolute expressions.

DPP Modifiers

dpp_ctrl

Specifies how data is shared between threads. This is a mandatory modifier. There is no default value.

Note: the lanes of a wavefront are organized in four rows and four banks.

Syntax

Description

quad_perm:[{0..3},{0..3},{0..3},{0..3}]

Full permute of 4 threads.

row_mirror

Mirror threads within row.

row_half_mirror

Mirror threads within 1/2 row (8 threads).

row_bcast:15

Broadcast the 15th thread of each row to the next row.

row_bcast:31

Broadcast thread 31 to rows 2 and 3.

wave_shl:1

Wavefront left shift by 1 thread.

wave_rol:1

Wavefront left rotate by 1 thread.

wave_shr:1

Wavefront right shift by 1 thread.

wave_ror:1

Wavefront right rotate by 1 thread.

row_shl:{1..15}

Row shift left by 1-15 threads.

row_shr:{1..15}

Row shift right by 1-15 threads.

row_ror:{1..15}

Row rotate right by 1-15 threads.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

quad_perm:[0, 1, 2, 3]
row_shl:3

dpp16_ctrl

Specifies how data is shared between threads. This is a mandatory modifier. There is no default value.

Note: the lanes of a wavefront are organized in four rows and four banks. (There are only two rows in wave32 mode.)

Syntax

Description

quad_perm:[{0..3},{0..3},{0..3},{0..3}]

Full permute of 4 threads.

row_mirror

Mirror threads within row.

row_half_mirror

Mirror threads within 1/2 row (8 threads).

row_share:{0..15}

Share the value from the specified lane with other lanes in the row.

row_xmask:{0..15}

Fetch from XOR(<current lane id>,<specified lane id>).

row_shl:{1..15}

Row shift left by 1-15 threads.

row_shr:{1..15}

Row shift right by 1-15 threads.

row_ror:{1..15}

Row rotate right by 1-15 threads.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

quad_perm:[0, 1, 2, 3]
row_shl:3

dpp32_ctrl

Specifies how data is shared between threads. This is a mandatory modifier. There is no default value.

Note: the lanes of a wavefront are organized in four rows and four banks.

Syntax

Description

quad_perm:[{0..3},{0..3},{0..3},{0..3}]

Full permute of 4 threads.

row_mirror

Mirror threads within row.

row_half_mirror

Mirror threads within 1/2 row (8 threads).

row_bcast:15

Broadcast the 15th thread of each row to the next row.

row_bcast:31

Broadcast thread 31 to rows 2 and 3.

wave_shl:1

Wavefront left shift by 1 thread.

wave_rol:1

Wavefront left rotate by 1 thread.

wave_shr:1

Wavefront right shift by 1 thread.

wave_ror:1

Wavefront right rotate by 1 thread.

row_shl:{1..15}

Row shift left by 1-15 threads.

row_shr:{1..15}

Row shift right by 1-15 threads.

row_ror:{1..15}

Row rotate right by 1-15 threads.

row_newbcast:{1..15}

Broadcast a thread within a row to the whole row.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

quad_perm:[0, 1, 2, 3]
row_shl:3

dpp64_ctrl

Specifies how data is shared between threads. This is a mandatory modifier. There is no default value.

Note: the lanes of a wavefront are organized in four rows and four banks.

Syntax

Description

row_newbcast:{1..15}

Broadcast a thread within a row to the whole row.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

row_newbcast:3

row_mask

Controls which rows are enabled for data sharing. By default, all rows are enabled.

Note: the lanes of a wavefront are organized in four rows and four banks. (There are only two rows in wave32 mode.)

Syntax

Description

row_mask:{0..15}

Specifies a row mask as a positive integer number or an absolute expression.

Each of the 4 bits in the mask controls one row (0 - disabled, 1 - enabled).

In wave32 mode, the values shall be limited to {0..7}.

Examples:

row_mask:0xf
row_mask:0b1010
row_mask:x|y

bank_mask

Controls which banks are enabled for data sharing. By default, all banks are enabled.

Note: the lanes of a wavefront are organized in four rows and four banks. (There are only two rows in wave32 mode.)

Syntax

Description

bank_mask:{0..15}

Specifies a bank mask as a positive integer number or an absolute expression.

Each of the 4 bits in the mask controls one bank (0 - disabled, 1 - enabled).

Examples:

bank_mask:0x3
bank_mask:0b0011
bank_mask:x&y

bound_ctrl

Controls data sharing when accessing an invalid lane. By default, data sharing with invalid lanes is disabled.

Syntax

Description

bound_ctrl:1

Enables data sharing with invalid lanes.

Accessing data from an invalid lane will return zero.

Warning

For historical reasons, bound_ctrl:0 has the same meaning as bound_ctrl:1.

fi

Controls interaction with inactive lanes for dpp16 instructions. The default value is zero.

Note: inactive lanes are those whose exec mask bit is zero.

Syntax

Description

fi:0

Interaction with inactive lanes is controlled by bound_ctrl.

fi:1

Fetch pre-existing values from inactive lanes.

Note: numeric values may be specified as either integer numbers or absolute expressions.

SDWA Modifiers

clamp

See a description here.

omod

See a description here.

dst_sel

Selects which bits in the destination are affected. By default, all bits are affected.

Syntax

Description

dst_sel:DWORD

Use bits 31:0.

dst_sel:BYTE_0

Use bits 7:0.

dst_sel:BYTE_1

Use bits 15:8.

dst_sel:BYTE_2

Use bits 23:16.

dst_sel:BYTE_3

Use bits 31:24.

dst_sel:WORD_0

Use bits 15:0.

dst_sel:WORD_1

Use bits 31:16.

dst_unused

Controls what to do with the bits in the destination which are not selected by dst_sel. By default, unused bits are preserved.

Syntax

Description

dst_unused:UNUSED_PAD

Pad with zeros.

dst_unused:UNUSED_SEXT

Sign-extend upper bits, zero lower bits.

dst_unused:UNUSED_PRESERVE

Preserve bits.

src0_sel

Controls which bits in the src0 are used. By default, all bits are used.

Syntax

Description

src0_sel:DWORD

Use bits 31:0.

src0_sel:BYTE_0

Use bits 7:0.

src0_sel:BYTE_1

Use bits 15:8.

src0_sel:BYTE_2

Use bits 23:16.

src0_sel:BYTE_3

Use bits 31:24.

src0_sel:WORD_0

Use bits 15:0.

src0_sel:WORD_1

Use bits 31:16.

src1_sel

Controls which bits in the src1 are used. By default, all bits are used.

Syntax

Description

src1_sel:DWORD

Use bits 31:0.

src1_sel:BYTE_0

Use bits 7:0.

src1_sel:BYTE_1

Use bits 15:8.

src1_sel:BYTE_2

Use bits 23:16.

src1_sel:BYTE_3

Use bits 31:24.

src1_sel:WORD_0

Use bits 15:0.

src1_sel:WORD_1

Use bits 31:16.

SDWA Operand Modifiers

Operand modifiers are not used separately. They are applied to source operands.

abs

See a description here.

neg

See a description here.

sext

Sign-extends the value of a (sub-dword) integer operand to fill all 32 bits.

Valid for integer operands only.

Syntax

Description

sext(<operand>)

Sign-extend operand value.

Examples:

sext(v4)
sext(v255)

VOP3 Modifiers

op_sel

Selects the low [15:0] or high [31:16] operand bits for source and destination operands. By default, low bits are used for all operands.

The number of values specified with the op_sel modifier must match the number of instruction operands (both source and destination). The first value controls src0, the second value controls src1 and so on, except that the last value controls destination. The value 0 selects the low bits, while 1 selects the high bits.

Note: op_sel modifier affects 16-bit operands only. For 32-bit operands, the value specified by op_sel must be 0.

Syntax

Description

op_sel:[{0..1},{0..1}]

Select operand bits for instructions with 1 source operand.

op_sel:[{0..1},{0..1},{0..1}]

Select operand bits for instructions with 2 source operands.

op_sel:[{0..1},{0..1},{0..1},{0..1}]

Select operand bits for instructions with 3 source operands.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

op_sel:[0,0]
op_sel:[0,1]

dpp_op_sel

This is a special version of op_sel used for permlane opcodes to specify dpp-like mode bits - fi and bound_ctrl.

Syntax

Description

op_sel:[{0..1},{0..1}]

The first bit specifies fi, the second bit specifies bound_ctrl.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

op_sel:[0,0]

clamp

Clamp meaning depends on instruction.

For v_cmp instructions, clamp modifier indicates that the compare signals if a floating-point exception occurs. By default, signaling is disabled.

For integer operations, clamp modifier indicates that the result must be clamped to the largest and smallest representable value. By default, there is no clamping.

For floating-point operations, clamp modifier indicates that the result must be clamped to the range [0.0, 1.0]. By default, there is no clamping.

Note: clamp modifier is applied after output modifiers (if any).

Syntax

Description

clamp

Enables clamping (or signaling).

omod

Specifies if an output modifier must be applied to the result. It is assumed that the result is a floating-point number.

By default, no output modifiers are applied.

Note: output modifiers are applied before clamping (if any).

Syntax

Description

mul:2

Multiply the result by 2.

mul:4

Multiply the result by 4.

div:2

Multiply the result by 0.5.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

mul:2
mul:x      // x must be equal to 2 or 4

VOP3 Operand Modifiers

Operand modifiers are not used separately. They are applied to source operands.

abs

Computes the absolute value of its operand. Must be applied before neg (if any). Valid for floating-point operands only.

Syntax

Description

abs(<operand>)

Get the absolute value of a floating-point operand.

|<operand>|

The same as above (an SP3 syntax).

Note: avoid using SP3 syntax with operands specified as expressions because the trailing ‘|’ may be misinterpreted. Such operands should be enclosed into additional parentheses, as shown in examples below.

Examples:

abs(v36)
|v36|
abs(x|y)     // ok
|(x|y)|      // additional parentheses are required

neg

Computes the negative value of its operand. Must be applied after abs (if any). Valid for floating-point operands only.

Syntax

Description

neg(<operand>)

Get the negative value of a floating-point operand. An optional abs modifier may be applied to the operand before negation.

-<operand>

The same as above (an SP3 syntax).

Note: SP3 syntax is supported with limitations because of a potential ambiguity. Currently, it is allowed in the following cases:

  • Before a register.

  • Before an abs modifier.

  • Before an SP3 abs modifier.

In all other cases, “-” is handled as a part of an expression that follows the sign.

Examples:

// Operands with negate modifiers
neg(v[0])
neg(1.0)
neg(abs(v0))
-v5
-abs(v5)
-|v5|

// Expressions where "-" has a different meaning
-1
-x+y

VOP3P Modifiers

This section describes modifiers of regular VOP3P instructions.

v_mad_mix* and v_fma_mix* instructions use these modifiers in a special manner.

op_sel

Selects the low [15:0] or high [31:16] operand bits as input to the operation, which results in the lower-half of the destination. By default, low 16 bits are used for all operands.

The number of values specified by the op_sel modifier must match the number of source operands. The first value controls src0, the second value controls src1 and so on.

The value 0 selects the low bits, while 1 selects the high bits.

Syntax

Description

op_sel:[{0..1}]

Select operand bits for instructions with 1 source operand.

op_sel:[{0..1},{0..1}]

Select operand bits for instructions with 2 source operands.

op_sel:[{0..1},{0..1},{0..1}]

Select operand bits for instructions with 3 source operands.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

op_sel:[0,0]
op_sel:[0,1,0]

op_sel_hi

Selects the low [15:0] or high [31:16] operand bits as input to the operation, which results in the upper-half of the destination. By default, high 16 bits are used for all operands.

The number of values specified by the op_sel_hi modifier must match the number of source operands. The first value controls src0, the second value controls src1 and so on.

The value 0 selects the low bits, while 1 selects the high bits.

Syntax

Description

op_sel_hi:[{0..1}]

Select operand bits for instructions with 1 source operand.

op_sel_hi:[{0..1},{0..1}]

Select operand bits for instructions with 2 source operands.

op_sel_hi:[{0..1},{0..1},{0..1}]

Select operand bits for instructions with 3 source operands.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

op_sel_hi:[0,0]
op_sel_hi:[0,0,1]

neg_lo

Specifies whether to change the sign of operand values selected by op_sel. These values are then used as input to the operation, which results in the upper-half of the destination.

The number of values specified by this modifier must match the number of source operands. The first value controls src0, the second value controls src1 and so on.

The value 0 indicates that the corresponding operand value is used unmodified, the value 1 indicates that the negative value of the operand must be used.

By default, operand values are used unmodified.

This modifier is valid for floating-point operands only.

Syntax

Description

neg_lo:[{0..1}]

Select affected operands for instructions with 1 source operand.

neg_lo:[{0..1},{0..1}]

Select affected operands for instructions with 2 source operands.

neg_lo:[{0..1},{0..1},{0..1}]

Select affected operands for instructions with 3 source operands.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

neg_lo:[0]
neg_lo:[0,1]

neg_hi

Specifies whether to change sign of operand values selected by op_sel_hi. These values are then used as input to the operation, which results in the upper-half of the destination.

The number of values specified by this modifier must match the number of source operands. The first value controls src0, the second value controls src1 and so on.

The value 0 indicates that the corresponding operand value is used unmodified, the value 1 indicates that the negative value of the operand must be used.

By default, operand values are used unmodified.

This modifier is valid for floating-point operands only.

Syntax

Description

neg_hi:[{0..1}]

Select affected operands for instructions with 1 source operand.

neg_hi:[{0..1},{0..1}]

Select affected operands for instructions with 2 source operands.

neg_hi:[{0..1},{0..1},{0..1}]

Select affected operands for instructions with 3 source operands.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

neg_hi:[1,0]
neg_hi:[0,1,1]

clamp

See a description here.

VOP3P MAD_MIX/FMA_MIX Modifiers

v_mad_mix* and v_fma_mix* instructions use op_sel and op_sel_hi modifiers in a manner different from regular VOP3P instructions.

See a description below.

m_op_sel

This operand has meaning only for 16-bit source operands, as indicated by m_op_sel_hi. It specifies to select either the low [15:0] or high [31:16] operand bits as input to the operation.

The number of values specified by the op_sel modifier must match the number of source operands. The first value controls src0, the second value controls src1 and so on.

The value 0 indicates the low bits, the value 1 indicates the high 16 bits.

By default, low bits are used for all operands.

Syntax

Description

op_sel:[{0..1},{0..1},{0..1}]

Select the location of each 16-bit source operand.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

op_sel:[0,1]

m_op_sel_hi

Selects the size of source operands: either 32 bits or 16 bits. By default, 32 bits are used for all source operands.

The number of values specified by the op_sel_hi modifier must match the number of source operands. The first value controls src0, the second value controls src1 and so on.

The value 0 indicates 32 bits, the value 1 indicates 16 bits.

The location of 16 bits in the operand may be specified by m_op_sel.

Syntax

Description

op_sel_hi:[{0..1},{0..1},{0..1}]

Select the size of each source operand.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

op_sel_hi:[1,1,1]

abs

See a description here.

neg

See a description here.

clamp

See a description here.

VOP3P MFMA Modifiers

cbsz

Specifies a broadcast mode.

Syntax

Description

cbsz:[{0..7}]

A broadcast mode.

Note: numeric value may be specified as either an integer number or an absolute expression.

abid

Specifies matrix A group select.

Syntax

Description

abid:[{0..15}]

Matrix A group select id.

Note: numeric value may be specified as either an integer number or an absolute expression.

blgp

Specifies matrix B lane group pattern.

Syntax

Description

blgp:[{0..7}]

Matrix B lane group pattern.

Note: numeric value may be specified as either an integer number or an absolute expression.

neg

Indicates operands that must be negated before the operation. The number of values specified by this modifier must match the number of source operands. The first value controls src0, the second value controls src1 and so on.

The value 0 indicates that the corresponding operand value is used unmodified, the value 1 indicates that the operand value must be negated before the operation.

By default, operand values are used unmodified.

Syntax

Description

neg:[{0..1},{0..1},{0..1}]

Select operands which must be negated before the operation.

Note: numeric values may be specified as either integer numbers or absolute expressions.

Examples:

neg:[0,1,1]