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authorStephen Hines <srhines@google.com>2015-04-01 18:49:24 +0000
committerGerrit Code Review <noreply-gerritcodereview@google.com>2015-04-01 18:49:26 +0000
commit3fa16bd6062e23bcdb82ed4dd965674792e6b761 (patch)
tree9348fc507292f7e8715d22d64ce5a32131b4f875 /lib/Target/BPF/BPFInstrInfo.cpp
parentbeed47390a60f6f0c77532b3d3f76bb47ef49423 (diff)
parentebe69fe11e48d322045d5949c83283927a0d790b (diff)
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Merge "Update aosp/master LLVM for rebase to r230699."
Diffstat (limited to 'lib/Target/BPF/BPFInstrInfo.cpp')
-rw-r--r--lib/Target/BPF/BPFInstrInfo.cpp168
1 files changed, 168 insertions, 0 deletions
diff --git a/lib/Target/BPF/BPFInstrInfo.cpp b/lib/Target/BPF/BPFInstrInfo.cpp
new file mode 100644
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+++ b/lib/Target/BPF/BPFInstrInfo.cpp
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+//===-- BPFInstrInfo.cpp - BPF Instruction Information ----------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the BPF implementation of the TargetInstrInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BPF.h"
+#include "BPFInstrInfo.h"
+#include "BPFSubtarget.h"
+#include "BPFTargetMachine.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
+
+#define GET_INSTRINFO_CTOR_DTOR
+#include "BPFGenInstrInfo.inc"
+
+using namespace llvm;
+
+BPFInstrInfo::BPFInstrInfo()
+ : BPFGenInstrInfo(BPF::ADJCALLSTACKDOWN, BPF::ADJCALLSTACKUP) {}
+
+void BPFInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I, DebugLoc DL,
+ unsigned DestReg, unsigned SrcReg,
+ bool KillSrc) const {
+ if (BPF::GPRRegClass.contains(DestReg, SrcReg))
+ BuildMI(MBB, I, DL, get(BPF::MOV_rr), DestReg)
+ .addReg(SrcReg, getKillRegState(KillSrc));
+ else
+ llvm_unreachable("Impossible reg-to-reg copy");
+}
+
+void BPFInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I,
+ unsigned SrcReg, bool IsKill, int FI,
+ const TargetRegisterClass *RC,
+ const TargetRegisterInfo *TRI) const {
+ DebugLoc DL;
+ if (I != MBB.end())
+ DL = I->getDebugLoc();
+
+ if (RC == &BPF::GPRRegClass)
+ BuildMI(MBB, I, DL, get(BPF::STD))
+ .addReg(SrcReg, getKillRegState(IsKill))
+ .addFrameIndex(FI)
+ .addImm(0);
+ else
+ llvm_unreachable("Can't store this register to stack slot");
+}
+
+void BPFInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator I,
+ unsigned DestReg, int FI,
+ const TargetRegisterClass *RC,
+ const TargetRegisterInfo *TRI) const {
+ DebugLoc DL;
+ if (I != MBB.end())
+ DL = I->getDebugLoc();
+
+ if (RC == &BPF::GPRRegClass)
+ BuildMI(MBB, I, DL, get(BPF::LDD), DestReg).addFrameIndex(FI).addImm(0);
+ else
+ llvm_unreachable("Can't load this register from stack slot");
+}
+
+bool BPFInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
+ MachineBasicBlock *&TBB,
+ MachineBasicBlock *&FBB,
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
+ // Start from the bottom of the block and work up, examining the
+ // terminator instructions.
+ MachineBasicBlock::iterator I = MBB.end();
+ while (I != MBB.begin()) {
+ --I;
+ if (I->isDebugValue())
+ continue;
+
+ // Working from the bottom, when we see a non-terminator
+ // instruction, we're done.
+ if (!isUnpredicatedTerminator(I))
+ break;
+
+ // A terminator that isn't a branch can't easily be handled
+ // by this analysis.
+ if (!I->isBranch())
+ return true;
+
+ // Handle unconditional branches.
+ if (I->getOpcode() == BPF::JMP) {
+ if (!AllowModify) {
+ TBB = I->getOperand(0).getMBB();
+ continue;
+ }
+
+ // If the block has any instructions after a J, delete them.
+ while (std::next(I) != MBB.end())
+ std::next(I)->eraseFromParent();
+ Cond.clear();
+ FBB = 0;
+
+ // Delete the J if it's equivalent to a fall-through.
+ if (MBB.isLayoutSuccessor(I->getOperand(0).getMBB())) {
+ TBB = 0;
+ I->eraseFromParent();
+ I = MBB.end();
+ continue;
+ }
+
+ // TBB is used to indicate the unconditinal destination.
+ TBB = I->getOperand(0).getMBB();
+ continue;
+ }
+ // Cannot handle conditional branches
+ return true;
+ }
+
+ return false;
+}
+
+unsigned BPFInstrInfo::InsertBranch(MachineBasicBlock &MBB,
+ MachineBasicBlock *TBB,
+ MachineBasicBlock *FBB,
+ const SmallVectorImpl<MachineOperand> &Cond,
+ DebugLoc DL) const {
+ // Shouldn't be a fall through.
+ assert(TBB && "InsertBranch must not be told to insert a fallthrough");
+
+ if (Cond.empty()) {
+ // Unconditional branch
+ assert(!FBB && "Unconditional branch with multiple successors!");
+ BuildMI(&MBB, DL, get(BPF::JMP)).addMBB(TBB);
+ return 1;
+ }
+
+ llvm_unreachable("Unexpected conditional branch");
+}
+
+unsigned BPFInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
+ MachineBasicBlock::iterator I = MBB.end();
+ unsigned Count = 0;
+
+ while (I != MBB.begin()) {
+ --I;
+ if (I->isDebugValue())
+ continue;
+ if (I->getOpcode() != BPF::JMP)
+ break;
+ // Remove the branch.
+ I->eraseFromParent();
+ I = MBB.end();
+ ++Count;
+ }
+
+ return Count;
+}