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AMDGPUModifierSyntax.rst

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Syntax of AMDGPU Instruction Modifiers

The following notation is used throughout this document:

NotationDescription
{0..N}Any integer value in the range from 0 to N (inclusive).
<x>Syntax and meaning of x is explained elsewhere.

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

Used with DS instructions which have 2 addresses.

SyntaxDescription
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 

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

Used with DS instructions which have 1 address.

SyntaxDescription
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 

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.

SyntaxDescription
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) 

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

SyntaxDescription
gdsUse GDS memory.

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

SyntaxDescription
doneIndicates the last export operation.

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

SyntaxDescription
comprData are compressed.

Specifies valid mask flag state (off by default).

SyntaxDescription
vmSet valid mask flag.

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

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

SyntaxDescription
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 

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

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

SyntaxDescription
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 

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

Can be used with global/scratch opcodes only.

GFX10 only.

SyntaxDescription
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 

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

Cannot be used with global/scratch opcodes.

GFX10 only.

SyntaxDescription
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 

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

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

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

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

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

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

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

SyntaxDescription
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 KindValid dmask Values
32-bit atomic cmpswap0x3
32-bit atomic instructions except for cmpswap0x1
64-bit atomic cmpswap0xF
64-bit atomic instructions except for cmpswap0x3
gather40x1, 0x2, 0x4, 0x8
Other instructionsany value

Examples:

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

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

SyntaxDescription
unormForce the address to be unnormalized.

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

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

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

GFX7, GFX8 and GFX10 only.

SyntaxDescription
r128Specifies 128 bits texture resource size.

Warning

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

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

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

SyntaxDescription
lweEnables LOD warning.

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

SyntaxDescription
daSend an array-index to TA.

Specifies data size: 16 or 32 bits (32 bits by default). Not supported by GFX7.

SyntaxDescription
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.

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

SyntaxDescription
a16Enables 16-bits image address components.

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

GFX10 only.

SyntaxDescription
dim:1DOne-dimensional image.
dim:2DTwo-dimensional image.
dim:3DThree-dimensional image.
dim:CUBECubemap array.
dim:1D_ARRAYOne-dimensional image array.
dim:2D_ARRAYTwo-dimensional image array.
dim:2D_MSAATwo-dimensional multi-sample auto-aliasing image.
dim:2D_MSAA_ARRAYTwo-dimensional multi-sample auto-aliasing image array.

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

SyntaxDescription
dim:SQ_RSRC_IMG_1DOne-dimensional image.
dim:SQ_RSRC_IMG_2DTwo-dimensional image.
dim:SQ_RSRC_IMG_3DThree-dimensional image.
dim:SQ_RSRC_IMG_CUBECubemap array.
dim:SQ_RSRC_IMG_1D_ARRAYOne-dimensional image array.
dim:SQ_RSRC_IMG_2D_ARRAYTwo-dimensional image array.
dim:SQ_RSRC_IMG_2D_MSAATwo-dimensional multi-sample auto-aliasing image.
dim:SQ_RSRC_IMG_2D_MSAA_ARRAYTwo-dimensional multi-sample auto-aliasing image array.

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

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.

SyntaxDescription
dlcBypass device level cache.

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

See AMD documentation for details.

SyntaxDescription
glcSet glc bit to 1.

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

SyntaxDescription
ldsStore result in LDS.

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

GFX9 only.

SyntaxDescription
nvIndicates that instruction operates on non-volatile memory.

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

See AMD documentation for details.

SyntaxDescription
slcSet slc bit to 1.

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

See AMD documentation for details.

SyntaxDescription
tfeSet tfe bit to 1.

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>`.

SyntaxDescription
idxenAddress components include an index.

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>`.

SyntaxDescription
offenAddress components include an offset.

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.

SyntaxDescription
addr64A 64-bit address is used.

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

SyntaxDescription
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 

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

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

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

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

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

TBD

TBD

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

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

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

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

SyntaxDescription
highUse high half of LDS word.

GFX10 only.

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>`.

SyntaxDescription
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] 

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.

SyntaxDescription
fi:0Fetch zero when accessing data from inactive lanes.
fi:1Fetch 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>`.

GFX8, GFX9 and GFX10 only.

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.

SyntaxDescription
quad_perm:[{0..3},{0..3},{0..3},{0..3}]Full permute of 4 threads.
row_mirrorMirror threads within row.
row_half_mirrorMirror threads within 1/2 row (8 threads).
row_bcast:15Broadcast 15th thread of each row to next row.
row_bcast:31Broadcast thread 31 to rows 2 and 3.
wave_shl:1Wavefront left shift by 1 thread.
wave_rol:1Wavefront left rotate by 1 thread.
wave_shr:1Wavefront right shift by 1 thread.
wave_ror:1Wavefront 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 

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.)

SyntaxDescription
quad_perm:[{0..3},{0..3},{0..3},{0..3}]Full permute of 4 threads.
row_mirrorMirror threads within row.
row_half_mirrorMirror 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 

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.)

SyntaxDescription
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 

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.)

SyntaxDescription
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 

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

SyntaxDescription
bound_ctrl:0

Enables data sharing with invalid lanes.

Accessing data from an invalid lane will return zero.

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.

SyntaxDescription
fi:0Interaction with inactive lanes is controlled by :ref:`bound_ctrl<amdgpu_synid_bound_ctrl>`.
fi:1Fetch 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>`.

GFX8, GFX9 and GFX10 only.

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

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

GFX9 and GFX10 only.

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

SyntaxDescription
dst_sel:DWORDUse bits 31:0.
dst_sel:BYTE_0Use bits 7:0.
dst_sel:BYTE_1Use bits 15:8.
dst_sel:BYTE_2Use bits 23:16.
dst_sel:BYTE_3Use bits 31:24.
dst_sel:WORD_0Use bits 15:0.
dst_sel:WORD_1Use bits 31:16.

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.

SyntaxDescription
dst_unused:UNUSED_PADPad with zeros.
dst_unused:UNUSED_SEXTSign-extend upper bits, zero lower bits.
dst_unused:UNUSED_PRESERVEPreserve bits.

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

SyntaxDescription
src0_sel:DWORDUse bits 31:0.
src0_sel:BYTE_0Use bits 7:0.
src0_sel:BYTE_1Use bits 15:8.
src0_sel:BYTE_2Use bits 23:16.
src0_sel:BYTE_3Use bits 31:24.
src0_sel:WORD_0Use bits 15:0.
src0_sel:WORD_1Use bits 31:16.

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

SyntaxDescription
src1_sel:DWORDUse bits 31:0.
src1_sel:BYTE_0Use bits 7:0.
src1_sel:BYTE_1Use bits 15:8.
src1_sel:BYTE_2Use bits 23:16.
src1_sel:BYTE_3Use bits 31:24.
src1_sel:WORD_0Use bits 15:0.
src1_sel:WORD_1Use bits 31:16.

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

GFX8, GFX9 and GFX10 only.

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

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

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.

SyntaxDescription
sext(<operand>)Sign-extend operand value.

Examples:

sext(v4) sext(v255) 

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.

SyntaxDescription
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 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).

SyntaxDescription
clampEnables clamping (or signaling).

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.

SyntaxDescription
mul:2Multiply the result by 2.
mul:4Multiply the result by 4.
div:2Multiply 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 

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

Computes the absolute value of its operand. Must be applied before :ref:`neg<amdgpu_synid_neg>` (if any). Valid for floating point operands only.

SyntaxDescription
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 

Computes the negative value of its operand. Must be applied after :ref:`abs<amdgpu_synid_abs>` (if any). Valid for floating point operands only.

SyntaxDescription
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:

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 

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.

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.

SyntaxDescription
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] 

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.

SyntaxDescription
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] 

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.

SyntaxDescription
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] 

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.

SyntaxDescription
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] 

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

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.

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.

SyntaxDescription
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] 

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>`.

SyntaxDescription
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] 

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

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

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

SyntaxDescription
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>`.

SyntaxDescription
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>`.

SyntaxDescription
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>`.

close