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Diffstat (limited to 'src/gpgpu-sim/shader.cc')
| -rw-r--r-- | src/gpgpu-sim/shader.cc | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/gpgpu-sim/shader.cc b/src/gpgpu-sim/shader.cc index d7b0c68..5779537 100644 --- a/src/gpgpu-sim/shader.cc +++ b/src/gpgpu-sim/shader.cc @@ -723,6 +723,17 @@ void shader_core_ctx::writeback() { warp_inst_t *&pipe_reg = m_pipeline_reg[EX_WB]; if( !pipe_reg->empty()) { + /* + * The operand collector writeback can generally generate a stall + * However, here, the pipelines should be un-stallable. This is + * guaranteed because this is the first time the writeback function + * is called after the operand collector's step function, which + * resets the allocations. There is one case which could result in + * the writeback function returning false (stall), which is when + * an instruction tries to modify two registers (GPR and predicate) + * To handle this case, we ignore the return value (thus allowing + * no stalling). + */ m_operand_collector.writeback(*pipe_reg); unsigned warp_id = pipe_reg->warp_id(); m_scoreboard->releaseRegisters( pipe_reg ); |