ARM: do not generate BLX instructions on Cortex-M CPUs.

[oota-llvm.git] / lib / Target / ARM / ARMBaseInstrInfo.cpp

diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 0288db91dcbf01d9ee0ed3c539899f77b21421c6..d78a26fee0f6b01291ff8ae9263e213decbb256d 100644 (file)
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -108,7 +108,7 @@ ARMBaseInstrInfo::CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
                                                const ScheduleDAG *DAG) const {
   if (usePreRAHazardRecognizer()) {
     const InstrItineraryData *II =
-        &static_cast<const ARMSubtarget *>(STI)->getInstrItineraryData();
+        static_cast<const ARMSubtarget *>(STI)->getInstrItineraryData();
     return new ScoreboardHazardRecognizer(II, DAG, "pre-RA-sched");
   }
   return TargetInstrInfo::CreateTargetHazardRecognizer(STI, DAG);
@@ -1174,7 +1174,20 @@ unsigned ARMBaseInstrInfo::isLoadFromStackSlotPostFE(const MachineInstr *MI,
   return MI->mayLoad() && hasLoadFromStackSlot(MI, Dummy, FrameIndex);
 }
 
-bool ARMBaseInstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MI) const{
+bool
+ARMBaseInstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MI) const {
+  MachineFunction &MF = *MI->getParent()->getParent();
+  Reloc::Model RM = MF.getTarget().getRelocationModel();
+
+  if (MI->getOpcode() == TargetOpcode::LOAD_STACK_GUARD) {
+    assert(getSubtarget().getTargetTriple().getObjectFormat() ==
+           Triple::MachO &&
+           "LOAD_STACK_GUARD currently supported only for MachO.");
+    expandLoadStackGuard(MI, RM);
+    MI->getParent()->erase(MI);
+    return true;
+  }
+
   // This hook gets to expand COPY instructions before they become
   // copyPhysReg() calls.  Look for VMOVS instructions that can legally be
   // widened to VMOVD.  We prefer the VMOVD when possible because it may be
@@ -3933,6 +3946,38 @@ bool ARMBaseInstrInfo::verifyInstruction(const MachineInstr *MI,
   return true;
 }
 
+// LoadStackGuard has so far only been implemented for MachO. Different code
+// sequence is needed for other targets.
+void ARMBaseInstrInfo::expandLoadStackGuardBase(MachineBasicBlock::iterator MI,
+                                                unsigned LoadImmOpc,
+                                                unsigned LoadOpc,
+                                                Reloc::Model RM) const {
+  MachineBasicBlock &MBB = *MI->getParent();
+  DebugLoc DL = MI->getDebugLoc();
+  unsigned Reg = MI->getOperand(0).getReg();
+  const GlobalValue *GV =
+      cast<GlobalValue>((*MI->memoperands_begin())->getValue());
+  MachineInstrBuilder MIB;
+
+  BuildMI(MBB, MI, DL, get(LoadImmOpc), Reg)
+      .addGlobalAddress(GV, 0, ARMII::MO_NONLAZY);
+
+  if (Subtarget.GVIsIndirectSymbol(GV, RM)) {
+    MIB = BuildMI(MBB, MI, DL, get(LoadOpc), Reg);
+    MIB.addReg(Reg, RegState::Kill).addImm(0);
+    unsigned Flag = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant;
+    MachineMemOperand *MMO = MBB.getParent()->
+        getMachineMemOperand(MachinePointerInfo::getGOT(), Flag, 4, 4);
+    MIB.addMemOperand(MMO);
+    AddDefaultPred(MIB);
+  }
+
+  MIB = BuildMI(MBB, MI, DL, get(LoadOpc), Reg);
+  MIB.addReg(Reg, RegState::Kill).addImm(0);
+  MIB.setMemRefs(MI->memoperands_begin(), MI->memoperands_end());
+  AddDefaultPred(MIB);
+}
+
 bool
 ARMBaseInstrInfo::isFpMLxInstruction(unsigned Opcode, unsigned &MulOpc,
                                      unsigned &AddSubOpc,