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-rw-r--r--include/llvm/CodeGen/MachineTraceMetrics.h57
1 files changed, 49 insertions, 8 deletions
diff --git a/include/llvm/CodeGen/MachineTraceMetrics.h b/include/llvm/CodeGen/MachineTraceMetrics.h
index 460730b040..9794707e35 100644
--- a/include/llvm/CodeGen/MachineTraceMetrics.h
+++ b/include/llvm/CodeGen/MachineTraceMetrics.h
@@ -107,6 +107,13 @@ public:
/// Get the fixed resource information about MBB. Compute it on demand.
const FixedBlockInfo *getResources(const MachineBasicBlock*);
+ /// Get the scaled number of cycles used per processor resource in MBB.
+ /// This is an array with SchedModel.getNumProcResourceKinds() entries.
+ /// The getResources() function above must have been called first.
+ ///
+ /// These numbers have already been scaled by SchedModel.getResourceFactor().
+ ArrayRef<unsigned> getProcResourceCycles(unsigned MBBNum) const;
+
/// A virtual register or regunit required by a basic block or its trace
/// successors.
struct LiveInReg {
@@ -165,12 +172,25 @@ public:
/// Invalidate height resources when a block below this one has changed.
void invalidateHeight() { InstrHeight = ~0u; HasValidInstrHeights = false; }
- /// Determine if this block belongs to the same trace as TBI and comes
- /// before it in the trace.
+ /// Assuming that this is a dominator of TBI, determine if it contains
+ /// useful instruction depths. A dominating block can be above the current
+ /// trace head, and any dependencies from such a far away dominator are not
+ /// expected to affect the critical path.
+ ///
/// Also returns true when TBI == this.
- bool isEarlierInSameTrace(const TraceBlockInfo &TBI) const {
- return hasValidDepth() && TBI.hasValidDepth() &&
- Head == TBI.Head && InstrDepth <= TBI.InstrDepth;
+ bool isUsefulDominator(const TraceBlockInfo &TBI) const {
+ // The trace for TBI may not even be calculated yet.
+ if (!hasValidDepth() || !TBI.hasValidDepth())
+ return false;
+ // Instruction depths are only comparable if the traces share a head.
+ if (Head != TBI.Head)
+ return false;
+ // It is almost always the case that TBI belongs to the same trace as
+ // this block, but rare convoluted cases involving irreducible control
+ // flow, a dominator may share a trace head without actually being on the
+ // same trace as TBI. This is not a big problem as long as it doesn't
+ // increase the instruction depth.
+ return HasValidInstrDepths && InstrDepth <= TBI.InstrDepth;
}
// Data-dependency-related information. Per-instruction depth and height
@@ -240,9 +260,12 @@ public:
/// independent, exposing the maximum instruction-level parallelism.
///
/// Any blocks in Extrablocks are included as if they were part of the
- /// trace.
- unsigned getResourceLength(ArrayRef<const MachineBasicBlock*> Extrablocks =
- ArrayRef<const MachineBasicBlock*>()) const;
+ /// trace. Likewise, extra resources required by the specified scheduling
+ /// classes are included. For the caller to account for extra machine
+ /// instructions, it must first resolve each instruction's scheduling class.
+ unsigned getResourceLength(
+ ArrayRef<const MachineBasicBlock*> Extrablocks = None,
+ ArrayRef<const MCSchedClassDesc*> ExtraInstrs = None) const;
/// Return the length of the (data dependency) critical path through the
/// trace.
@@ -271,6 +294,8 @@ public:
class Ensemble {
SmallVector<TraceBlockInfo, 4> BlockInfo;
DenseMap<const MachineInstr*, InstrCycles> Cycles;
+ SmallVector<unsigned, 0> ProcResourceDepths;
+ SmallVector<unsigned, 0> ProcResourceHeights;
friend class Trace;
void computeTrace(const MachineBasicBlock*);
@@ -290,6 +315,8 @@ public:
const MachineLoop *getLoopFor(const MachineBasicBlock*) const;
const TraceBlockInfo *getDepthResources(const MachineBasicBlock*) const;
const TraceBlockInfo *getHeightResources(const MachineBasicBlock*) const;
+ ArrayRef<unsigned> getProcResourceDepths(unsigned MBBNum) const;
+ ArrayRef<unsigned> getProcResourceHeights(unsigned MBBNum) const;
public:
virtual ~Ensemble();
@@ -330,8 +357,22 @@ private:
// One entry per basic block, indexed by block number.
SmallVector<FixedBlockInfo, 4> BlockInfo;
+ // Cycles consumed on each processor resource per block.
+ // The number of processor resource kinds is constant for a given subtarget,
+ // but it is not known at compile time. The number of cycles consumed by
+ // block B on processor resource R is at ProcResourceCycles[B*Kinds + R]
+ // where Kinds = SchedModel.getNumProcResourceKinds().
+ SmallVector<unsigned, 0> ProcResourceCycles;
+
// One ensemble per strategy.
Ensemble* Ensembles[TS_NumStrategies];
+
+ // Convert scaled resource usage to a cycle count that can be compared with
+ // latencies.
+ unsigned getCycles(unsigned Scaled) {
+ unsigned Factor = SchedModel.getLatencyFactor();
+ return (Scaled + Factor - 1) / Factor;
+ }
};
inline raw_ostream &operator<<(raw_ostream &OS,