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User Guide for R600 Back-end

Introduction

The R600 back-end provides ISA code generation for AMD GPUs, starting with the R600 family up until the current Sea Islands (GCN Gen 2).

Assembler

The assembler is currently a work in progress and not yet complete. Below are the currently supported features.

SOPP Instructions

Unless otherwise mentioned, all SOPP instructions that with an operand accept a integer operand(s) only. No verification is performed on the operands, so it is up to the programmer to be familiar with the range or acceptable values.

s_waitcnt

s_waitcnt accepts named arguments to specify which memory counter(s) to wait for.

// Wait for all counters to be 0
s_waitcnt 0

// Equivalent to s_waitcnt 0.  Counter names can also be delimited by
// '&' or ','.
s_waitcnt vmcnt(0) expcnt(0) lgkcmt(0)

// Wait for vmcnt counter to be 1.
s_waitcnt vmcnt(1)