From 0114258120f1e9113b9a1feeaf150fc5514087ef Mon Sep 17 00:00:00 2001 From: Patrick Holland Date: Sun, 20 Jun 2021 19:12:00 -0700 Subject: [PATCH] [MCA] [In-order pipeline] Fix for 0 latency instruction causing assertion to fail. 0 latency instructions now get processed and retired properly within the in-order pipeline. Had to fix a bug within TimelineView.cpp as well that would show up when a 0 latency instruction was the first instruction in the source. Differential Revision: https://reviews.llvm.org/D104675 --- lib/MCA/Stages/InOrderIssueStage.cpp | 12 ++++++++++++ tools/llvm-mca/Views/TimelineView.cpp | 2 -- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/MCA/Stages/InOrderIssueStage.cpp b/lib/MCA/Stages/InOrderIssueStage.cpp index a5dad7cd28c..ccf6f20a673 100644 --- a/lib/MCA/Stages/InOrderIssueStage.cpp +++ b/lib/MCA/Stages/InOrderIssueStage.cpp @@ -241,6 +241,18 @@ llvm::Error InOrderIssueStage::tryIssue(InstRef &IR) { Bandwidth = Desc.EndGroup ? 0 : Bandwidth - NumMicroOps; } + // If the instruction has a latency of 0, we need to handle + // the execution and retirement now. + if (IS.isExecuted()) { + PRF.onInstructionExecuted(&IS); + notifyEvent( + HWInstructionEvent(HWInstructionEvent::Executed, IR)); + LLVM_DEBUG(dbgs() << "[E] Instruction #" << IR << " is executed\n"); + + retireInstruction(IR); + return llvm::ErrorSuccess(); + } + IssuedInst.push_back(IR); if (!IR.getInstruction()->getDesc().RetireOOO) diff --git a/tools/llvm-mca/Views/TimelineView.cpp b/tools/llvm-mca/Views/TimelineView.cpp index ceeb267cf11..5cd163cad01 100644 --- a/tools/llvm-mca/Views/TimelineView.cpp +++ b/tools/llvm-mca/Views/TimelineView.cpp @@ -288,8 +288,6 @@ void TimelineView::printTimeline(raw_ostream &OS) const { for (unsigned Iteration = 0; Iteration < Iterations; ++Iteration) { for (const MCInst &Inst : Source) { const TimelineViewEntry &Entry = Timeline[IID]; - if (Entry.CycleRetired == 0) - return; unsigned SourceIndex = IID % Source.size(); printTimelineViewEntry(FOS, Entry, Iteration, SourceIndex);