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-rw-r--r--lib/Target/TargetMachine.cpp279
1 files changed, 279 insertions, 0 deletions
diff --git a/lib/Target/TargetMachine.cpp b/lib/Target/TargetMachine.cpp
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+//===-- TargetMachine.cpp - General Target Information ---------------------==//
+//
+// This file describes the general parts of a Target machine.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Target/Machine.h"
+#include "llvm/DerivedTypes.h"
+
+// External object describing the machine instructions
+// Initialized only when the TargetMachine class is created
+// and reset when that class is destroyed.
+//
+const MachineInstrDescriptor* TargetInstrDescriptors = NULL;
+
+resourceId_t MachineResource::nextId = 0;
+
+static cycles_t ComputeMinGap (const InstrRUsage& fromRU,
+ const InstrRUsage& toRU);
+
+static bool RUConflict (const vector<resourceId_t>& fromRVec,
+ const vector<resourceId_t>& fromRVec);
+
+//---------------------------------------------------------------------------
+// class TargetMachine
+//
+// Purpose:
+// Machine description.
+//
+//---------------------------------------------------------------------------
+
+
+// function TargetMachine::findOptimalStorageSize
+//
+// Purpose:
+// This default implementation assumes that all sub-word data items use
+// space equal to optSizeForSubWordData, and all other primitive data
+// items use space according to the type.
+//
+unsigned int TargetMachine::findOptimalStorageSize(const Type* ty) const {
+ switch(ty->getPrimitiveID()) {
+ case Type::BoolTyID:
+ case Type::UByteTyID:
+ case Type::SByteTyID:
+ case Type::UShortTyID:
+ case Type::ShortTyID:
+ return optSizeForSubWordData;
+
+ default:
+ return DataLayout.getTypeSize(ty);
+ }
+}
+
+
+//---------------------------------------------------------------------------
+// class MachineInstructionInfo
+// Interface to description of machine instructions
+//---------------------------------------------------------------------------
+
+
+/*ctor*/
+MachineInstrInfo::MachineInstrInfo(const MachineInstrDescriptor* _desc,
+ unsigned int _descSize,
+ unsigned int _numRealOpCodes)
+ : desc(_desc), descSize(_descSize), numRealOpCodes(_numRealOpCodes)
+{
+ assert(TargetInstrDescriptors == NULL && desc != NULL);
+ TargetInstrDescriptors = desc; // initialize global variable
+}
+
+
+/*dtor*/
+MachineInstrInfo::~MachineInstrInfo()
+{
+ TargetInstrDescriptors = NULL; // reset global variable
+}
+
+
+bool
+MachineInstrInfo::constantFitsInImmedField(MachineOpCode opCode,
+ int64_t intValue) const
+{
+ // First, check if opCode has an immed field.
+ bool isSignExtended;
+ uint64_t maxImmedValue = this->maxImmedConstant(opCode, isSignExtended);
+ if (maxImmedValue != 0)
+ {
+ // Now check if the constant fits
+ if (intValue <= (int64_t) maxImmedValue &&
+ intValue >= -((int64_t) maxImmedValue+1))
+ return true;
+ }
+
+ return false;
+}
+
+
+//---------------------------------------------------------------------------
+// class MachineSchedInfo
+// Interface to machine description for instruction scheduling
+//---------------------------------------------------------------------------
+
+/*ctor*/
+MachineSchedInfo::MachineSchedInfo(int _numSchedClasses,
+ const MachineInstrInfo* _mii,
+ const InstrClassRUsage* _classRUsages,
+ const InstrRUsageDelta* _usageDeltas,
+ const InstrIssueDelta* _issueDeltas,
+ unsigned int _numUsageDeltas,
+ unsigned int _numIssueDeltas)
+ : numSchedClasses(_numSchedClasses),
+ mii(_mii),
+ classRUsages(_classRUsages),
+ usageDeltas(_usageDeltas),
+ issueDeltas(_issueDeltas),
+ numUsageDeltas(_numUsageDeltas),
+ numIssueDeltas(_numIssueDeltas)
+{
+}
+
+void
+MachineSchedInfo::initializeResources()
+{
+ assert(MAX_NUM_SLOTS >= (int) getMaxNumIssueTotal()
+ && "Insufficient slots for static data! Increase MAX_NUM_SLOTS");
+
+ // First, compute common resource usage info for each class because
+ // most instructions will probably behave the same as their class.
+ // Cannot allocate a vector of InstrRUsage so new each one.
+ //
+ vector<InstrRUsage> instrRUForClasses;
+ instrRUForClasses.resize(numSchedClasses);
+ for (InstrSchedClass sc=0; sc < numSchedClasses; sc++)
+ {
+ // instrRUForClasses.push_back(new InstrRUsage);
+ instrRUForClasses[sc].setMaxSlots(getMaxNumIssueTotal());
+ instrRUForClasses[sc] = classRUsages[sc];
+ }
+
+ computeInstrResources(instrRUForClasses);
+
+ computeIssueGaps(instrRUForClasses);
+}
+
+
+void
+MachineSchedInfo::computeInstrResources(const vector<InstrRUsage>& instrRUForClasses)
+{
+ int numOpCodes = mii->getNumRealOpCodes();
+ instrRUsages.resize(numOpCodes);
+
+ // First get the resource usage information from the class resource usages.
+ for (MachineOpCode op=0; op < numOpCodes; op++)
+ {
+ InstrSchedClass sc = getSchedClass(op);
+ assert(sc >= 0 && sc < numSchedClasses);
+ instrRUsages[op] = instrRUForClasses[sc];
+ }
+
+ // Now, modify the resource usages as specified in the deltas.
+ for (unsigned i=0; i < numUsageDeltas; i++)
+ {
+ MachineOpCode op = usageDeltas[i].opCode;
+ assert(op < numOpCodes);
+ instrRUsages[op].addUsageDelta(usageDeltas[i]);
+ }
+
+ // Then modify the issue restrictions as specified in the deltas.
+ for (unsigned i=0; i < numIssueDeltas; i++)
+ {
+ MachineOpCode op = issueDeltas[i].opCode;
+ assert(op < numOpCodes);
+ instrRUsages[issueDeltas[i].opCode].addIssueDelta(issueDeltas[i]);
+ }
+}
+
+
+void
+MachineSchedInfo::computeIssueGaps(const vector<InstrRUsage>& instrRUForClasses)
+{
+ int numOpCodes = mii->getNumRealOpCodes();
+ instrRUsages.resize(numOpCodes);
+
+ assert(numOpCodes < (1 << MAX_OPCODE_SIZE) - 1
+ && "numOpCodes invalid for implementation of class OpCodePair!");
+
+ // First, compute issue gaps between pairs of classes based on common
+ // resources usages for each class, because most instruction pairs will
+ // usually behave the same as their class.
+ //
+ int classPairGaps[numSchedClasses][numSchedClasses];
+ for (InstrSchedClass fromSC=0; fromSC < numSchedClasses; fromSC++)
+ for (InstrSchedClass toSC=0; toSC < numSchedClasses; toSC++)
+ {
+ int classPairGap = ComputeMinGap(instrRUForClasses[fromSC],
+ instrRUForClasses[toSC]);
+ classPairGaps[fromSC][toSC] = classPairGap;
+ }
+
+ // Now, for each pair of instructions, use the class pair gap if both
+ // instructions have identical resource usage as their respective classes.
+ // If not, recompute the gap for the pair from scratch.
+
+ longestIssueConflict = 0;
+
+ for (MachineOpCode fromOp=0; fromOp < numOpCodes; fromOp++)
+ for (MachineOpCode toOp=0; toOp < numOpCodes; toOp++)
+ {
+ int instrPairGap =
+ (instrRUsages[fromOp].sameAsClass && instrRUsages[toOp].sameAsClass)
+ ? classPairGaps[getSchedClass(fromOp)][getSchedClass(toOp)]
+ : ComputeMinGap(instrRUsages[fromOp], instrRUsages[toOp]);
+
+ if (instrPairGap > 0)
+ {
+ issueGaps[OpCodePair(fromOp,toOp)] = instrPairGap;
+ conflictLists[fromOp].push_back(toOp);
+ longestIssueConflict = max(longestIssueConflict, instrPairGap);
+ }
+ }
+}
+
+
+// Check if fromRVec and toRVec have *any* common entries.
+// Assume the vectors are sorted in increasing order.
+// Algorithm copied from function set_intersection() for sorted ranges (stl_algo.h).
+inline static bool
+RUConflict(const vector<resourceId_t>& fromRVec,
+ const vector<resourceId_t>& toRVec)
+{
+ bool commonElementFound = false;
+
+ unsigned fN = fromRVec.size(), tN = toRVec.size();
+ unsigned fi = 0, ti = 0;
+ while (fi < fN && ti < tN)
+ if (fromRVec[fi] < toRVec[ti])
+ ++fi;
+ else if (toRVec[ti] < fromRVec[fi])
+ ++ti;
+ else
+ {
+ commonElementFound = true;
+ break;
+ }
+
+ return commonElementFound;
+}
+
+
+static cycles_t
+ComputeMinGap(const InstrRUsage& fromRU, const InstrRUsage& toRU)
+{
+ cycles_t minGap = 0;
+
+ if (fromRU.numBubbles > 0)
+ minGap = fromRU.numBubbles;
+
+ if (minGap < fromRU.numCycles)
+ {
+ // only need to check from cycle `minGap' onwards
+ for (cycles_t gap=minGap; gap <= fromRU.numCycles-1; gap++)
+ {
+ // check if instr. #2 can start executing `gap' cycles after #1
+ // by checking for resource conflicts in each overlapping cycle
+ cycles_t numOverlap = min(fromRU.numCycles - gap, toRU.numCycles);
+ for (cycles_t c = 0; c <= numOverlap-1; c++)
+ if (RUConflict(fromRU.resourcesByCycle[gap + c],
+ toRU.resourcesByCycle[c]))
+ {// conflict found so minGap must be more than `gap'
+ minGap = gap+1;
+ break;
+ }
+ }
+ }
+
+ return minGap;
+}
+
+//---------------------------------------------------------------------------