hwregΒΆ

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_XCC_ID

ID of this XCC (compute accelerator chip).

HW_REG_SQ_PERF_SNAPSHOT_DATA

Performance snapshot data (first part).

HW_REG_SQ_PERF_SNAPSHOT_DATA1

Performance snapshot data (second part).

HW_REG_SQ_PERF_SNAPSHOT_PC_LO

PC.lo of wave when snapshot was taken.

HW_REG_SQ_PERF_SNAPSHOT_PC_HI

PC.hi of wave when snapshot was taken.

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)