Prep for merging 3.4: Undo changes from 3.3 branch

lib/Target/X86/X86FrameLowering.cpp

Index: lib/Target/X86/X86FrameLowering.cpp
diff --git a/lib/Target/X86/X86FrameLowering.cpp b/lib/Target/X86/X86FrameLowering.cpp
index 89485cb06c309a6608ec601f15f0c1ba72b10b7b..fd0f6532485468a429cce599fa8b4a7ed3d63af6 100644
--- a/lib/Target/X86/X86FrameLowering.cpp
+++ b/lib/Target/X86/X86FrameLowering.cpp
@@ -372,14 +372,7 @@ void X86FrameLowering::emitCalleeSavedFrameMoves(MachineFunction &MF,
 /// getCompactUnwindRegNum - Get the compact unwind number for a given
 /// register. The number corresponds to the enum lists in
 /// compact_unwind_encoding.h.
-static int getCompactUnwindRegNum(unsigned Reg, bool is64Bit) {
-  static const uint16_t CU32BitRegs[] = {
-    X86::EBX, X86::ECX, X86::EDX, X86::EDI, X86::ESI, X86::EBP, 0
-  };
-  static const uint16_t CU64BitRegs[] = {
-    X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
-  };
-  const uint16_t *CURegs = is64Bit ? CU64BitRegs : CU32BitRegs;
+static int getCompactUnwindRegNum(const uint16_t *CURegs, unsigned Reg) {
   for (int Idx = 1; *CURegs; ++CURegs, ++Idx)
     if (*CURegs == Reg)
       return Idx;
@@ -408,8 +401,16 @@ encodeCompactUnwindRegistersWithoutFrame(unsigned SavedRegs[CU_NUM_SAVED_REGS],
   //     4       3
   //     5       3
   //
+  static const uint16_t CU32BitRegs[] = {
+    X86::EBX, X86::ECX, X86::EDX, X86::EDI, X86::ESI, X86::EBP, 0
+  };
+  static const uint16_t CU64BitRegs[] = {
+    X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
+  };
+  const uint16_t *CURegs = (Is64Bit ? CU64BitRegs : CU32BitRegs);
+
   for (unsigned i = 0; i != CU_NUM_SAVED_REGS; ++i) {
-    int CUReg = getCompactUnwindRegNum(SavedRegs[i], Is64Bit);
+    int CUReg = getCompactUnwindRegNum(CURegs, SavedRegs[i]);
     if (CUReg == -1) return ~0U;
     SavedRegs[i] = CUReg;
   }
@@ -468,6 +469,14 @@ encodeCompactUnwindRegistersWithoutFrame(unsigned SavedRegs[CU_NUM_SAVED_REGS],
 static uint32_t
 encodeCompactUnwindRegistersWithFrame(unsigned SavedRegs[CU_NUM_SAVED_REGS],
                                       bool Is64Bit) {
+  static const uint16_t CU32BitRegs[] = {
+    X86::EBX, X86::ECX, X86::EDX, X86::EDI, X86::ESI, X86::EBP, 0
+  };
+  static const uint16_t CU64BitRegs[] = {
+    X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
+  };
+  const uint16_t *CURegs = (Is64Bit ? CU64BitRegs : CU32BitRegs);
+
   // Encode the registers in the order they were saved, 3-bits per register. The
   // registers are numbered from 1 to CU_NUM_SAVED_REGS.
   uint32_t RegEnc = 0;
@@ -475,7 +484,7 @@ encodeCompactUnwindRegistersWithFrame(unsigned SavedRegs[CU_NUM_SAVED_REGS],
     unsigned Reg = SavedRegs[I];
     if (Reg == 0) continue;
 
-    int CURegNum = getCompactUnwindRegNum(Reg, Is64Bit);
+    int CURegNum = getCompactUnwindRegNum(CURegs, Reg);
     if (CURegNum == -1) return ~0U;
 
     // Encode the 3-bit register number in order, skipping over 3-bits for each
@@ -528,12 +537,6 @@ uint32_t X86FrameLowering::getCompactUnwindEncoding(MachineFunction &MF) const {
       // If there are too many saved registers, we cannot use compact encoding.
       if (SavedRegIdx >= CU_NUM_SAVED_REGS) return CU::UNWIND_MODE_DWARF;
 
-      unsigned Reg = MI.getOperand(0).getReg();
-      if (Reg == (Is64Bit ? X86::RAX : X86::EAX)) {
-        ExpectEnd = true;
-        continue;
-      }
-
       SavedRegs[SavedRegIdx++] = MI.getOperand(0).getReg();
       StackAdjust += OffsetSize;
       InstrOffset += PushInstrSize;