hwreg

Bits of a hardware register being accessed.

The bits of this operand have the following meaning:

Bits	Description	Value Range
5:0	Register id.	0..63
10:6	First bit offset.	0..31
15:11	Size in bits.	1..32

This operand may be specified as one of the following:

• An integer_number or an absolute_expression. The value must be in the range 0..0xFFFF.

• An hwreg value described below.

  Hwreg Value Syntax	Description
  hwreg({0..63})	All bits of a register indicated by its id.
  hwreg(<name>)	All bits of a register indicated by its name.
  hwreg({0..63}, {0..31}, {1..32})	Register bits indicated by register id, first bit offset and size.
  hwreg(<name>, {0..31}, {1..32})	Register bits indicated by register name, first bit offset and size.

Numeric values may be specified as positive integer numbers or absolute expressions.

Defined register names include:

Name	Description
HW_REG_MODE	Shader writeable mode bits.
HW_REG_STATUS	Shader read-only status.
HW_REG_TRAPSTS	Trap status.
HW_REG_HW_ID	Id of wave, simd, compute unit, etc.
HW_REG_GPR_ALLOC	Per-wave SGPR and VGPR allocation.
HW_REG_LDS_ALLOC	Per-wave LDS allocation.
HW_REG_IB_STS	Counters of outstanding instructions.
HW_REG_SH_MEM_BASES	Memory aperture.
HW_REG_TBA_LO	tba_lo register.
HW_REG_TBA_HI	tba_hi register.
HW_REG_TMA_LO	tma_lo register.
HW_REG_TMA_HI	tma_hi register.
HW_REG_FLAT_SCR_LO	flat_scratch_lo register.
HW_REG_FLAT_SCR_HI	flat_scratch_hi register.
HW_REG_XNACK_MASK	xnack_mask register.
HW_REG_POPS_PACKER	pops_packer register.

Examples:

reg = 1
offset = 2
size = 4
hwreg_enc = reg | (offset << 6) | ((size - 1) << 11)

s_getreg_b32 s2, 0x1881
s_getreg_b32 s2, hwreg_enc                     // the same as above
s_getreg_b32 s2, hwreg(1, 2, 4)                // the same as above
s_getreg_b32 s2, hwreg(reg, offset, size)      // the same as above

s_getreg_b32 s2, hwreg(15)
s_getreg_b32 s2, hwreg(51, 1, 31)
s_getreg_b32 s2, hwreg(HW_REG_LDS_ALLOC, 0, 1)