Implement Thumb2 ldr.

[oota-llvm.git] / lib / Target / X86 / X86RegisterInfo.cpp

diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index c733f26a8c8fa09337ad8cf2c482f553140b599f..a2f319f9a7ab769ec11d9347722dd8d00fc5120f 100644 (file)
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -662,6 +662,10 @@ void X86RegisterInfo::emitFrameMoves(MachineFunction &MF,
      TargetFrameInfo::StackGrowsUp ?
      TD->getPointerSize() : -TD->getPointerSize());
 
+  MachineLocation FPDst(hasFP(MF) ? FramePtr : StackPtr);
+  MachineLocation FPSrc(MachineLocation::VirtualFP);
+  Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
+
   if (StackSize) {
     // Show update of SP.
     if (hasFP(MF)) {
@@ -676,7 +680,7 @@ void X86RegisterInfo::emitFrameMoves(MachineFunction &MF,
       Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
     }
   } else {
-    //FIXME: Verify & implement for FP
+    // FIXME: Verify & implement for FP
     MachineLocation SPDst(StackPtr);
     MachineLocation SPSrc(StackPtr, stackGrowth);
     Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
@@ -711,10 +715,6 @@ void X86RegisterInfo::emitFrameMoves(MachineFunction &MF,
     MachineLocation FPSrc(FramePtr);
     Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
   }
-
-  MachineLocation FPDst(hasFP(MF) ? FramePtr : StackPtr);
-  MachineLocation FPSrc(MachineLocation::VirtualFP);
-  Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
 }
 
 
@@ -729,8 +729,7 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
   bool needsFrameMoves = (MMI && MMI->hasDebugInfo()) ||
                           !Fn->doesNotThrow() ||
                           UnwindTablesMandatory;
-  DebugLoc DL = (MBBI != MBB.end() ? MBBI->getDebugLoc() :
-                 DebugLoc::getUnknownLoc());
+  DebugLoc DL;
 
   // Prepare for frame info.
   unsigned FrameLabelId = 0;
@@ -831,63 +830,62 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
   if (MBBI != MBB.end())
     DL = MBBI->getDebugLoc();
 
-  if (NumBytes) {   // Adjust stack pointer: ESP -= numbytes.
-    if (NumBytes >= 4096 && Subtarget->isTargetCygMing()) {
-      // Check, whether EAX is livein for this function.
-      bool isEAXAlive = false;
-      for (MachineRegisterInfo::livein_iterator
+  // Adjust stack pointer: ESP -= numbytes.
+  if (NumBytes >= 4096 && Subtarget->isTargetCygMing()) {
+    // Check, whether EAX is livein for this function.
+    bool isEAXAlive = false;
+    for (MachineRegisterInfo::livein_iterator
            II = MF.getRegInfo().livein_begin(),
            EE = MF.getRegInfo().livein_end(); (II != EE) && !isEAXAlive; ++II) {
-        unsigned Reg = II->first;
-        isEAXAlive = (Reg == X86::EAX || Reg == X86::AX ||
-                      Reg == X86::AH  || Reg == X86::AL);
-      }
+      unsigned Reg = II->first;
+      isEAXAlive = (Reg == X86::EAX || Reg == X86::AX ||
+                    Reg == X86::AH || Reg == X86::AL);
+    }
 
-      // Function prologue calls _alloca to probe the stack when allocating more
-      // than 4k bytes in one go. Touching the stack at 4K increments is
-      // necessary to ensure that the guard pages used by the OS virtual memory
-      // manager are allocated in correct sequence.
-      if (!isEAXAlive) {
-        BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
-          .addImm(NumBytes);
-        BuildMI(MBB, MBBI, DL, TII.get(X86::CALLpcrel32))
-          .addExternalSymbol("_alloca");
-      } else {
-        // Save EAX
-        BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
-          .addReg(X86::EAX, RegState::Kill);
-
-        // Allocate NumBytes-4 bytes on stack. We'll also use 4 already
-        // allocated bytes for EAX.
-        BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
-          .addImm(NumBytes-4);
-        BuildMI(MBB, MBBI, DL, TII.get(X86::CALLpcrel32))
-          .addExternalSymbol("_alloca");
-
-        // Restore EAX
-        MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm),
-                                                X86::EAX),
-                                        StackPtr, false, NumBytes-4);
-        MBB.insert(MBBI, MI);
-      }
+    // Function prologue calls _alloca to probe the stack when allocating more
+    // than 4k bytes in one go. Touching the stack at 4K increments is necessary
+    // to ensure that the guard pages used by the OS virtual memory manager are
+    // allocated in correct sequence.
+    if (!isEAXAlive) {
+      BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
+        .addImm(NumBytes);
+      BuildMI(MBB, MBBI, DL, TII.get(X86::CALLpcrel32))
+        .addExternalSymbol("_alloca");
     } else {
-      // If there is an SUB32ri of ESP immediately before this instruction,
-      // merge the two. This can be the case when tail call elimination is
-      // enabled and the callee has more arguments then the caller.
-      NumBytes -= mergeSPUpdates(MBB, MBBI, StackPtr, true);
+      // Save EAX
+      BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
+        .addReg(X86::EAX, RegState::Kill);
+
+      // Allocate NumBytes-4 bytes on stack. We'll also use 4 already
+      // allocated bytes for EAX.
+      BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
+        .addImm(NumBytes - 4);
+      BuildMI(MBB, MBBI, DL, TII.get(X86::CALLpcrel32))
+        .addExternalSymbol("_alloca");
+
+      // Restore EAX
+      MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm),
+                                              X86::EAX),
+                                      StackPtr, false, NumBytes - 4);
+      MBB.insert(MBBI, MI);
+    }
+  } else if (NumBytes) {
+    // If there is an SUB32ri of ESP immediately before this instruction, merge
+    // the two. This can be the case when tail call elimination is enabled and
+    // the callee has more arguments then the caller.
+    NumBytes -= mergeSPUpdates(MBB, MBBI, StackPtr, true);
 
-      // If there is an ADD32ri or SUB32ri of ESP immediately after this
-      // instruction, merge the two instructions.
-      mergeSPUpdatesDown(MBB, MBBI, StackPtr, &NumBytes);
+    // If there is an ADD32ri or SUB32ri of ESP immediately after this
+    // instruction, merge the two instructions.
+    mergeSPUpdatesDown(MBB, MBBI, StackPtr, &NumBytes);
 
-      if (NumBytes)
-        emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII);
-    }
+    if (NumBytes)
+      emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII);
   }
 
   if (needsFrameMoves) {
-    // Mark effective beginning of when frame pointer is ready.
     unsigned ReadyLabelId = 0;
+    // Mark effective beginning of when frame pointer is ready.
     ReadyLabelId = MMI->NextLabelID();
     BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(ReadyLabelId);
     emitFrameMoves(MF, FrameLabelId, ReadyLabelId);