============================ AMDGPU Instructions Notation ============================ .. contents:: :local: .. _amdgpu_syn_instruction_notation: Introduction ============ This is an overview of notation used to describe the syntax of AMDGPU assembler instructions. This notation looks a lot like the :ref:`syntax of assembler instructions`, except that instead of real operands and modifiers, it uses references to their descriptions. Instructions ============ Notation ~~~~~~~~ This is the notation used to describe AMDGPU instructions: | ``<``\ :ref:`opcode description`\ ``> <``\ :ref:`operands description`\ ``> <``\ :ref:`modifiers description`\ ``>`` .. _amdgpu_syn_opcode_notation: Opcode ====== Notation ~~~~~~~~ TBD .. _amdgpu_syn_instruction_operands_notation: Operands ======== An instruction may have zero or more *operands*. They are comma-separated in the description: | ``<``\ :ref:`description of operand 0`\ ``>, <``\ :ref:`description of operand 1`\ ``>, ...`` The order of *operands* is fixed. *Operands* cannot be omitted except for special cases described below. .. _amdgpu_syn_instruction_operand_notation: Notation ~~~~~~~~ An operand is described using the following notation: *...* Where: * *kind* is an optional prefix describing operand :ref:`kind`. * *name* is a link to a description of the operand. * *tags* are optional. They are used to indicate :ref:`special operand properties`. .. _amdgpu_syn_instruction_operand_kinds: Operand Kinds ^^^^^^^^^^^^^ Operand kind indicates which values are accepted by the operand. * Operands which only accept *vector* registers are labelled with 'v' prefix. * Operands which only accept *scalar* registers and values are labelled with 's' prefix. * Operands which accept any registers and values have no prefix. Examples: .. parsed-literal:: vdata // operand only accepts vector registers sdst // operand only accepts scalar registers src1 // operand accepts vector registers, scalar registers, and scalar values .. _amdgpu_syn_instruction_operand_tags: Operand Tags ^^^^^^^^^^^^ Operand tags indicate special operand properties. ============== ================================================================================= Operand tag Meaning ============== ================================================================================= :opt An optional operand. :m An operand which may be used with operand modifiers :ref:`abs`, :ref:`neg` or :ref:`sext`. :dst An input operand which is also used as a destination if :ref:`glc` modifier is specified. :fx This is a *f32* or *f16* operand, depending on :ref:`m_op_sel_hi` modifier. : The operand *type* differs from the *type* :ref:`implied by the opcode name`. This tag specifies the actual operand *type*. ============== ================================================================================= Examples: .. parsed-literal:: src1:m // src1 operand may be used with operand modifiers vdata:dst // vdata operand may be used as both source and destination vdst:u32 // vdst operand has u32 type .. _amdgpu_syn_instruction_modifiers_notation: Modifiers ========= An instruction may have zero or more optional *modifiers*. They are space-separated in the description: | ``<``\ :ref:`description of modifier 0`\ ``> <``\ :ref:`description of modifier 1`\ ``> ...`` The order of *modifiers* is fixed. .. _amdgpu_syn_instruction_modifier_notation: Notation ~~~~~~~~ A *modifier* is described using the following notation: ** Where the *name* is a link to a description of the *modifier*.