//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "systemz-long-branch"
-
#include "SystemZTargetMachine.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
using namespace llvm;
+#define DEBUG_TYPE "systemz-long-branch"
+
STATISTIC(LongBranches, "Number of long branches.");
namespace {
- // Represents positional information about a basic block.
- struct MBBInfo {
- // The address that we currently assume the block has.
- uint64_t Address;
-
- // The size of the block in bytes, excluding terminators.
- // This value never changes.
- uint64_t Size;
-
- // The minimum alignment of the block, as a log2 value.
- // This value never changes.
- unsigned Alignment;
-
- // The number of terminators in this block. This value never changes.
- unsigned NumTerminators;
-
- MBBInfo()
- : Address(0), Size(0), Alignment(0), NumTerminators(0) {}
- };
-
- // Represents the state of a block terminator.
- struct TerminatorInfo {
- // If this terminator is a relaxable branch, this points to the branch
- // instruction, otherwise it is null.
- MachineInstr *Branch;
-
- // The address that we currently assume the terminator has.
- uint64_t Address;
-
- // The current size of the terminator in bytes.
- uint64_t Size;
-
- // If Branch is nonnull, this is the number of the target block,
- // otherwise it is unused.
- unsigned TargetBlock;
-
- // If Branch is nonnull, this is the length of the longest relaxed form,
- // otherwise it is zero.
- unsigned ExtraRelaxSize;
-
- TerminatorInfo() : Branch(0), Size(0), TargetBlock(0), ExtraRelaxSize(0) {}
- };
-
- // Used to keep track of the current position while iterating over the blocks.
- struct BlockPosition {
- // The address that we assume this position has.
- uint64_t Address;
-
- // The number of low bits in Address that are known to be the same
- // as the runtime address.
- unsigned KnownBits;
-
- BlockPosition(unsigned InitialAlignment)
- : Address(0), KnownBits(InitialAlignment) {}
- };
-
- class SystemZLongBranch : public MachineFunctionPass {
- public:
- static char ID;
- SystemZLongBranch(const SystemZTargetMachine &tm)
- : MachineFunctionPass(ID), TII(0) {}
-
- virtual const char *getPassName() const {
- return "SystemZ Long Branch";
- }
+// Represents positional information about a basic block.
+struct MBBInfo {
+ // The address that we currently assume the block has.
+ uint64_t Address;
+
+ // The size of the block in bytes, excluding terminators.
+ // This value never changes.
+ uint64_t Size;
+
+ // The minimum alignment of the block, as a log2 value.
+ // This value never changes.
+ unsigned Alignment;
+
+ // The number of terminators in this block. This value never changes.
+ unsigned NumTerminators;
+
+ MBBInfo()
+ : Address(0), Size(0), Alignment(0), NumTerminators(0) {}
+};
+
+// Represents the state of a block terminator.
+struct TerminatorInfo {
+ // If this terminator is a relaxable branch, this points to the branch
+ // instruction, otherwise it is null.
+ MachineInstr *Branch;
+
+ // The address that we currently assume the terminator has.
+ uint64_t Address;
+
+ // The current size of the terminator in bytes.
+ uint64_t Size;
+
+ // If Branch is nonnull, this is the number of the target block,
+ // otherwise it is unused.
+ unsigned TargetBlock;
+
+ // If Branch is nonnull, this is the length of the longest relaxed form,
+ // otherwise it is zero.
+ unsigned ExtraRelaxSize;
+
+ TerminatorInfo() : Branch(nullptr), Size(0), TargetBlock(0),
+ ExtraRelaxSize(0) {}
+};
+
+// Used to keep track of the current position while iterating over the blocks.
+struct BlockPosition {
+ // The address that we assume this position has.
+ uint64_t Address;
+
+ // The number of low bits in Address that are known to be the same
+ // as the runtime address.
+ unsigned KnownBits;
+
+ BlockPosition(unsigned InitialAlignment)
+ : Address(0), KnownBits(InitialAlignment) {}
+};
+
+class SystemZLongBranch : public MachineFunctionPass {
+public:
+ static char ID;
+ SystemZLongBranch(const SystemZTargetMachine &tm)
+ : MachineFunctionPass(ID), TII(nullptr) {}
+
+ const char *getPassName() const override {
+ return "SystemZ Long Branch";
+ }
- bool runOnMachineFunction(MachineFunction &F);
-
- private:
- void skipNonTerminators(BlockPosition &Position, MBBInfo &Block);
- void skipTerminator(BlockPosition &Position, TerminatorInfo &Terminator,
- bool AssumeRelaxed);
- TerminatorInfo describeTerminator(MachineInstr *MI);
- uint64_t initMBBInfo();
- bool mustRelaxBranch(const TerminatorInfo &Terminator, uint64_t Address);
- bool mustRelaxABranch();
- void setWorstCaseAddresses();
- void splitCompareBranch(MachineInstr *MI, unsigned CompareOpcode);
- void relaxBranch(TerminatorInfo &Terminator);
- void relaxBranches();
-
- const SystemZInstrInfo *TII;
- MachineFunction *MF;
- SmallVector<MBBInfo, 16> MBBs;
- SmallVector<TerminatorInfo, 16> Terminators;
- };
-
- char SystemZLongBranch::ID = 0;
-
- const uint64_t MaxBackwardRange = 0x10000;
- const uint64_t MaxForwardRange = 0xfffe;
-} // end of anonymous namespace
+ bool runOnMachineFunction(MachineFunction &F) override;
+
+private:
+ void skipNonTerminators(BlockPosition &Position, MBBInfo &Block);
+ void skipTerminator(BlockPosition &Position, TerminatorInfo &Terminator,
+ bool AssumeRelaxed);
+ TerminatorInfo describeTerminator(MachineInstr *MI);
+ uint64_t initMBBInfo();
+ bool mustRelaxBranch(const TerminatorInfo &Terminator, uint64_t Address);
+ bool mustRelaxABranch();
+ void setWorstCaseAddresses();
+ void splitBranchOnCount(MachineInstr *MI, unsigned AddOpcode);
+ void splitCompareBranch(MachineInstr *MI, unsigned CompareOpcode);
+ void relaxBranch(TerminatorInfo &Terminator);
+ void relaxBranches();
+
+ const SystemZInstrInfo *TII;
+ MachineFunction *MF;
+ SmallVector<MBBInfo, 16> MBBs;
+ SmallVector<TerminatorInfo, 16> Terminators;
+};
+
+char SystemZLongBranch::ID = 0;
+
+const uint64_t MaxBackwardRange = 0x10000;
+const uint64_t MaxForwardRange = 0xfffe;
+} // end anonymous namespace
FunctionPass *llvm::createSystemZLongBranchPass(SystemZTargetMachine &TM) {
return new SystemZLongBranch(TM);
// Relaxes to BRCL, which is 2 bytes longer.
Terminator.ExtraRelaxSize = 2;
break;
+ case SystemZ::BRCT:
+ case SystemZ::BRCTG:
+ // Relaxes to A(G)HI and BRCL, which is 6 bytes longer.
+ Terminator.ExtraRelaxSize = 6;
+ break;
case SystemZ::CRJ:
- // Relaxes to a CR/BRCL sequence, which is 2 bytes longer.
+ case SystemZ::CLRJ:
+ // Relaxes to a C(L)R/BRCL sequence, which is 2 bytes longer.
Terminator.ExtraRelaxSize = 2;
break;
case SystemZ::CGRJ:
- // Relaxes to a CGR/BRCL sequence, which is 4 bytes longer.
+ case SystemZ::CLGRJ:
+ // Relaxes to a C(L)GR/BRCL sequence, which is 4 bytes longer.
Terminator.ExtraRelaxSize = 4;
break;
case SystemZ::CIJ:
// Relaxes to a C(G)HI/BRCL sequence, which is 4 bytes longer.
Terminator.ExtraRelaxSize = 4;
break;
+ case SystemZ::CLIJ:
+ case SystemZ::CLGIJ:
+ // Relaxes to a CL(G)FI/BRCL sequence, which is 6 bytes longer.
+ Terminator.ExtraRelaxSize = 6;
+ break;
default:
llvm_unreachable("Unrecognized branch instruction");
}
// Return true if, under current assumptions, any terminator needs
// to be relaxed.
bool SystemZLongBranch::mustRelaxABranch() {
- for (SmallVectorImpl<TerminatorInfo>::iterator TI = Terminators.begin(),
- TE = Terminators.end(); TI != TE; ++TI)
- if (mustRelaxBranch(*TI, TI->Address))
+ for (auto &Terminator : Terminators)
+ if (mustRelaxBranch(Terminator, Terminator.Address))
return true;
return false;
}
void SystemZLongBranch::setWorstCaseAddresses() {
SmallVector<TerminatorInfo, 16>::iterator TI = Terminators.begin();
BlockPosition Position(MF->getAlignment());
- for (SmallVectorImpl<MBBInfo>::iterator BI = MBBs.begin(), BE = MBBs.end();
- BI != BE; ++BI) {
- skipNonTerminators(Position, *BI);
- for (unsigned BTI = 0, BTE = BI->NumTerminators; BTI != BTE; ++BTI) {
+ for (auto &Block : MBBs) {
+ skipNonTerminators(Position, Block);
+ for (unsigned BTI = 0, BTE = Block.NumTerminators; BTI != BTE; ++BTI) {
skipTerminator(Position, *TI, true);
++TI;
}
}
}
+// Split BRANCH ON COUNT MI into the addition given by AddOpcode followed
+// by a BRCL on the result.
+void SystemZLongBranch::splitBranchOnCount(MachineInstr *MI,
+ unsigned AddOpcode) {
+ MachineBasicBlock *MBB = MI->getParent();
+ DebugLoc DL = MI->getDebugLoc();
+ BuildMI(*MBB, MI, DL, TII->get(AddOpcode))
+ .addOperand(MI->getOperand(0))
+ .addOperand(MI->getOperand(1))
+ .addImm(-1);
+ MachineInstr *BRCL = BuildMI(*MBB, MI, DL, TII->get(SystemZ::BRCL))
+ .addImm(SystemZ::CCMASK_ICMP)
+ .addImm(SystemZ::CCMASK_CMP_NE)
+ .addOperand(MI->getOperand(2));
+ // The implicit use of CC is a killing use.
+ BRCL->addRegisterKilled(SystemZ::CC, &TII->getRegisterInfo());
+ MI->eraseFromParent();
+}
+
// Split MI into the comparison given by CompareOpcode followed
// a BRCL on the result.
void SystemZLongBranch::splitCompareBranch(MachineInstr *MI,
case SystemZ::BRC:
Branch->setDesc(TII->get(SystemZ::BRCL));
break;
+ case SystemZ::BRCT:
+ splitBranchOnCount(Branch, SystemZ::AHI);
+ break;
+ case SystemZ::BRCTG:
+ splitBranchOnCount(Branch, SystemZ::AGHI);
+ break;
case SystemZ::CRJ:
splitCompareBranch(Branch, SystemZ::CR);
break;
case SystemZ::CGIJ:
splitCompareBranch(Branch, SystemZ::CGHI);
break;
+ case SystemZ::CLRJ:
+ splitCompareBranch(Branch, SystemZ::CLR);
+ break;
+ case SystemZ::CLGRJ:
+ splitCompareBranch(Branch, SystemZ::CLGR);
+ break;
+ case SystemZ::CLIJ:
+ splitCompareBranch(Branch, SystemZ::CLFI);
+ break;
+ case SystemZ::CLGIJ:
+ splitCompareBranch(Branch, SystemZ::CLGFI);
+ break;
default:
llvm_unreachable("Unrecognized branch");
}
Terminator.Size += Terminator.ExtraRelaxSize;
Terminator.ExtraRelaxSize = 0;
- Terminator.Branch = 0;
+ Terminator.Branch = nullptr;
++LongBranches;
}
void SystemZLongBranch::relaxBranches() {
SmallVector<TerminatorInfo, 16>::iterator TI = Terminators.begin();
BlockPosition Position(MF->getAlignment());
- for (SmallVectorImpl<MBBInfo>::iterator BI = MBBs.begin(), BE = MBBs.end();
- BI != BE; ++BI) {
- skipNonTerminators(Position, *BI);
- for (unsigned BTI = 0, BTE = BI->NumTerminators; BTI != BTE; ++BTI) {
+ for (auto &Block : MBBs) {
+ skipNonTerminators(Position, Block);
+ for (unsigned BTI = 0, BTE = Block.NumTerminators; BTI != BTE; ++BTI) {
assert(Position.Address <= TI->Address &&
"Addresses shouldn't go forwards");
if (mustRelaxBranch(*TI, Position.Address))
}
bool SystemZLongBranch::runOnMachineFunction(MachineFunction &F) {
- TII = static_cast<const SystemZInstrInfo *>(F.getTarget().getInstrInfo());
+ TII = static_cast<const SystemZInstrInfo *>(F.getSubtarget().getInstrInfo());
MF = &F;
uint64_t Size = initMBBInfo();
if (Size <= MaxForwardRange || !mustRelaxABranch())