From dd556e8763da2d7c3961ed9c2ea977df16e94bfc Mon Sep 17 00:00:00 2001 From: Ross Thompson Date: Tue, 31 Jan 2023 14:54:05 -0600 Subject: [PATCH] Simplified RAS. --- pipelined/src/ifu/bpred/RASPredictor.sv | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/pipelined/src/ifu/bpred/RASPredictor.sv b/pipelined/src/ifu/bpred/RASPredictor.sv index 0c47aed99..6b2bdae4d 100644 --- a/pipelined/src/ifu/bpred/RASPredictor.sv +++ b/pipelined/src/ifu/bpred/RASPredictor.sv @@ -52,20 +52,21 @@ module RASPredictor #(parameter int StackSize = 16 )( logic IncrRepairD, DecRepairD; logic DecrementPtr; + logic FlushedRetDE; + logic WrongPredRetD; + assign PopF = PredInstrClassF[2] & ~StallD & ~FlushD; - - assign RepairD = ((WrongPredInstrClassD[2]) & ~StallE & ~FlushE) | // Wrong class undo increment or decrement. - (~StallE & FlushE & InstrClassD[2]) | // ret in decode flushed - (~StallM & FlushM & InstrClassE[2]) ; // ret in execution flushed - - assign IncrRepairD = (~StallE & FlushE & InstrClassD[2]) | // ret in decode flushed - (~StallM & FlushM & InstrClassE[2]) | // ret in execution flushed - (WrongPredInstrClassD[2] & ~InstrClassD[2] & ~StallE & ~FlushE); // Guessed it was a ret, but its not - - assign DecRepairD = (WrongPredInstrClassD[2] & InstrClassD[2] & ~StallE & ~FlushE); // Guessed non ret but is a ret. - assign PushE = InstrClassE[3] & ~StallM & ~FlushM; + + assign WrongPredRetD = (WrongPredInstrClassD[2]) & ~StallE & ~FlushE; + assign FlushedRetDE = (~StallE & FlushE & InstrClassD[2]) | (~StallM & FlushM & InstrClassE[2]); + + assign RepairD = WrongPredRetD | FlushedRetDE ; + + assign IncrRepairD = FlushedRetDE | (WrongPredRetD & ~InstrClassD[2]); // Guessed it was a ret, but its not + + assign DecRepairD = WrongPredRetD & InstrClassD[2]; // Guessed non ret but is a ret. assign CounterEn = PopF | PushE | RepairD;