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 is explained elsewhere.

Modifiers

DS Modifiers

offset8

Specifies an immediate unsigned 8-bit offset, in bytes. The default value is 0.

Used with DS instructions which have 2 addresses.

Syntax	Description
offset:{0..0xFF}	Specifies an unsigned 8-bit offset as a positive :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.

Examples:

offset:0xff
offset:2-x
offset:-x-y

offset16

Specifies an immediate unsigned 16-bit offset, in bytes. The default value is 0.

Used with DS instructions which have 1 address.

Syntax	Description
offset:{0..0xFFFF}	Specifies an unsigned 16-bit offset as a positive :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.

Examples:

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

swizzle pattern

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

See AMD documentation for more information.

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. 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 broadcasted. 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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

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, exp instruction does not finish an export sequence.

Syntax	Description
done	Indicates the last export operation.

compr

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

Syntax	Description
compr	Data are compressed.

vm

Specifies valid mask flag state (off by default).

Syntax	Description
vm	Set valid mask flag.

FLAT Modifiers

offset12

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

Cannot be used with global/scratch opcodes. GFX9 only.

Syntax	Description
offset:{0..4095}	Specifies a 12-bit unsigned offset as a positive :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.

Examples:

offset:4095
offset:x-0xff

offset13s

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

Can be used with global/scratch opcodes only. GFX9 only.

Syntax	Description
offset:{-4096..4095}	Specifies a 13-bit signed offset as an :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.

Examples:

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

offset12s

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

Can be used with global/scratch opcodes only.

GFX10 only.

Syntax	Description
offset:{-2048..2047}	Specifies a 12-bit signed offset as an :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_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.

Cannot be used with global/scratch opcodes.

GFX10 only.

Syntax	Description
offset:{0..2047}	Specifies an 11-bit unsigned offset as a positive :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.

Examples:

offset:2047
offset:x+0xff

dlc

See a description :ref:`here<amdgpu_synid_dlc>`. GFX10 only.

glc

See a description :ref:`here<amdgpu_synid_glc>`.

lds

See a description :ref:`here<amdgpu_synid_lds>`. GFX10 only.

slc

See a description :ref:`here<amdgpu_synid_slc>`.

tfe

See a description :ref:`here<amdgpu_synid_tfe>`.

nv

See a description :ref:`here<amdgpu_synid_nv>`.

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 :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`. Each bit corresponds to one of 4 image components (RGBA). If the specified bit value is 0, the component is not used, value 1 means that the component is used.

This modifier has some limitations depending on 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
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 unnormalized.

glc

See a description :ref:`here<amdgpu_synid_glc>`.

slc

See a description :ref:`here<amdgpu_synid_slc>`.

r128

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

GFX7, GFX8 and GFX10 only.

Syntax	Description
r128	Specifies 128 bits texture resource size.

tfe

See a description :ref:`here<amdgpu_synid_tfe>`.

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, 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). Not supported by GFX7.

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 going to memory. Note that GFX8.0 does not support data packing. Each 16-bit data element occupies 1 VGPR. GFX8.1, GFX9 and GFX10 support data packing. Each pair of 16-bit data elements occupies 1 VGPR.

a16

Specifies size of image address components: 16 or 32 bits (32 bits by default). GFX9 and GFX10 only.

Syntax	Description
a16	Enables 16-bits image address components.

dim

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

GFX10 only.

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 :ref:`here<amdgpu_synid_dlc>`. GFX10 only.

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.

GFX10 only.

Syntax	Description
dlc	Bypass device level cache.

glc

This modifier has different meaning for loads, stores, and atomic operations. The default value is off (0).

See AMD documentation for details.

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 result in LDS.

nv

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

GFX9 only.

Syntax	Description
nv	Indicates that instruction operates on non-volatile memory.

slc

Specifies cache policy. The default value is off (0).

See AMD documentation for details.

Syntax	Description
slc	Set slc bit to 1.

tfe

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

See AMD documentation for details.

Syntax	Description
tfe	Set tfe bit to 1.

MUBUF/MTBUF Modifiers

idxen

Specifies whether address components include an index. By default, no components are used.

Can be used together with :ref:`offen<amdgpu_synid_offen>`.

Cannot be used with :ref:`addr64<amdgpu_synid_addr64>`.

Syntax	Description
idxen	Address components include an index.

offen

Specifies whether address components include an offset. By default, no components are used.

Can be used together with :ref:`idxen<amdgpu_synid_idxen>`.

Cannot be used with :ref:`addr64<amdgpu_synid_addr64>`.

Syntax	Description
offen	Address components include an offset.

addr64

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

GFX7 only. Cannot be used with :ref:`offen<amdgpu_synid_offen>` and :ref:`idxen<amdgpu_synid_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 :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.

Examples:

offset:x+y
offset:0x10

glc

See a description :ref:`here<amdgpu_synid_glc>`.

slc

See a description :ref:`here<amdgpu_synid_slc>`.

lds

See a description :ref:`here<amdgpu_synid_lds>`.

dlc

See a description :ref:`here<amdgpu_synid_dlc>`. GFX10 only.

tfe

See a description :ref:`here<amdgpu_synid_tfe>`.

dfmt

TBD

nfmt

TBD

SMRD/SMEM Modifiers

glc

See a description :ref:`here<amdgpu_synid_glc>`.

nv

See a description :ref:`here<amdgpu_synid_nv>`. GFX9 only.

dlc

See a description :ref:`here<amdgpu_synid_dlc>`. GFX10 only.

VINTRP Modifiers

high

Specifies which half of the LDS word to use. Low half of LDS word is used by default. GFX9 and GFX10 only.

Syntax	Description
high	Use high half of LDS word.

DPP8 Modifiers

GFX10 only.

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.

GFX10 only.

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

Each value may be specified as either an :ref:`integer number<amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_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 :ref:`exec<amdgpu_synid_exec>` mask bit is zero.

GFX10 only.

Syntax	Description
fi:0	Fetch zero when accessing data from inactive lanes.
fi:1	Fetch pre-exist values from inactive lanes.

Note: numeric values may be specified as either :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

DPP/DPP16 Modifiers

GFX8, GFX9 and GFX10 only.

dpp_ctrl

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

GFX8 and GFX9 only. Use :ref:`dpp16_ctrl<amdgpu_synid_dpp16_ctrl>` for GFX10.

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 15th thread of each row to 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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

Examples:

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

dpp16_ctrl

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

GFX10 only. Use :ref:`dpp_ctrl<amdgpu_synid_dpp_ctrl>` for GFX8 and GFX9.

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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

Examples:

quad_perm:[0, 1, 2, 3]
row_shl: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 :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`. Each of 4 bits in the mask controls one row (0 - disabled, 1 - enabled). In wave32 mode the values should 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 :ref:`integer number <amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`. Each of 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:0	Enables data sharing with invalid lanes. Accessing data from an invalid lane will return zero.

fi

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

Note: inactive lanes are those whose :ref:`exec<amdgpu_synid_exec>` mask bit is zero.

GFX10 only.

Syntax	Description
fi:0	Interaction with inactive lanes is controlled by :ref:`bound_ctrl<amdgpu_synid_bound_ctrl>`.
fi:1	Fetch pre-exist values from inactive lanes.

Note: numeric values may be specified as either :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

SDWA Modifiers

GFX8, GFX9 and GFX10 only.

clamp

See a description :ref:`here<amdgpu_synid_clamp>`.

omod

See a description :ref:`here<amdgpu_synid_omod>`.

GFX9 and GFX10 only.

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 :ref:`dst_sel<amdgpu_synid_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.

GFX8, GFX9 and GFX10 only.

abs

See a description :ref:`here<amdgpu_synid_abs>`.

neg

See a description :ref:`here<amdgpu_synid_neg>`.

sext

Sign-extends value of a (sub-dword) operand to fill all 32 bits. Has no effect for 32-bit operands.

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). First value controls src0, 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.

GFX9 and GFX10 only.

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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

Examples:

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

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. Not supported by GFX7.

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. Integer clamping is not supported by GFX7.

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 :ref:`output modifiers<amdgpu_synid_omod>` (if any).

Syntax	Description
clamp	Enables clamping (or signaling).

omod

Specifies if an output modifier must be applied to the result. By default, no output modifiers are applied.

Note: output modifiers are applied before :ref:`clamping<amdgpu_synid_clamp>` (if any).

Output modifiers are valid for f32 and f64 floating point results only. They must not be used with f16.

Note: v_cvt_f16_f32 is an exception. This instruction produces f16 result but accepts output modifiers.

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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

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 :ref:`neg<amdgpu_synid_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 :ref:`abs<amdgpu_synid_abs>` (if any). Valid for floating point operands only.

Syntax	Description
neg(<operand>)	Get the negative value of a floating-point operand. The operand may include an optional :ref:`abs<amdgpu_synid_abs>` modifier.
-<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 :ref:`abs<amdgpu_synid_abs>` modifier.
• Before an SP3 :ref:`abs<amdgpu_synid_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|

// Operands without negate modifiers
-1
-x+y

VOP3P Modifiers

This section describes modifiers of regular VOP3P instructions.

v_mad_mix* and v_fma_mix* instructions use these modifiers :ref:`in a special manner<amdgpu_synid_mad_mix>`.

GFX9 and GFX10 only.

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 bits are used for all operands.

The number of values specified by the op_sel modifier must match the number of source operands. First value controls src0, 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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

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 bits are used for all operands.

The number of values specified by the op_sel_hi modifier must match the number of source operands. First value controls src0, 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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

Examples:

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

neg_lo

Specifies whether to change sign of operand values selected by :ref:`op_sel<amdgpu_synid_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. First value controls src0, second value controls src1 and so on.

The value 0 indicates that the corresponding operand value is used unmodified, the value 1 indicates that 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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

Examples:

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

neg_hi

Specifies whether to change sign of operand values selected by :ref:`op_sel_hi<amdgpu_synid_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. First value controls src0, second value controls src1 and so on.

The value 0 indicates that the corresponding operand value is used unmodified, the value 1 indicates that 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 :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

Examples:

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

clamp

See a description :ref:`here<amdgpu_synid_clamp>`.

VOP3P V_MAD_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.

GFX9 and GFX10 only.

m_op_sel

This operand has meaning only for 16-bit source operands as indicated by :ref:`m_op_sel_hi<amdgpu_synid_mad_mix_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. First value controls src0, 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 location of each 16-bit source operand.

Note: numeric values may be specified as either :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

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. First value controls src0, 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 :ref:`m_op_sel<amdgpu_synid_mad_mix_op_sel>`.

Syntax	Description
op_sel_hi:[{0..1},{0..1},{0..1}]	Select size of each source operand.

Note: numeric values may be specified as either :ref:`integer numbers<amdgpu_synid_integer_number>` or :ref:`absolute expressions<amdgpu_synid_absolute_expression>`.

Examples:

op_sel_hi:[1,1,1]

abs

See a description :ref:`here<amdgpu_synid_abs>`.

neg

See a description :ref:`here<amdgpu_synid_neg>`.

clamp

See a description :ref:`here<amdgpu_synid_clamp>`.

VOP3P MFMA Modifiers

cbsz

Syntax	Description
cbsz:[{0..7}]	TBD

Note: numeric value may be specified as either an :ref:`integer number<amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.

abid

Syntax	Description
abid:[{0..15}]	TBD

Note: numeric value may be specified as either an :ref:`integer number<amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.

blgp

Syntax	Description
blgp:[{0..7}]	TBD

Note: numeric value may be specified as either an :ref:`integer number<amdgpu_synid_integer_number>` or an :ref:`absolute expression<amdgpu_synid_absolute_expression>`.