1 files changed, 196 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMUnwindOpAsm.cpp b/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMUnwindOpAsm.cpp
new file mode 100644
index 0000000..173cc93
--- /dev/null
+++ b/contrib/llvm/lib/Target/ARM/MCTargetDesc/ARMUnwindOpAsm.cpp
@@ -0,0 +1,196 @@
+//===-- ARMUnwindOpAsm.cpp - ARM Unwind Opcodes Assembler -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the unwind opcode assmebler for ARM exception handling
+// table.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARMUnwindOpAsm.h"
+#include "llvm/Support/ARMEHABI.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/LEB128.h"
+
+using namespace llvm;
+
+namespace {
+  /// UnwindOpcodeStreamer - The simple wrapper over SmallVector to emit bytes
+  /// with MSB to LSB per uint32_t ordering.  For example, the first byte will
+  /// be placed in Vec[3], and the following bytes will be placed in 2, 1, 0,
+  /// 7, 6, 5, 4, 11, 10, 9, 8, and so on.
+  class UnwindOpcodeStreamer {
+  private:
+    SmallVectorImpl<uint8_t> &Vec;
+    size_t Pos;
+
+  public:
+    UnwindOpcodeStreamer(SmallVectorImpl<uint8_t> &V) : Vec(V), Pos(3) {
+    }
+
+    /// Emit the byte in MSB to LSB per uint32_t order.
+    inline void EmitByte(uint8_t elem) {
+      Vec[Pos] = elem;
+      Pos = (((Pos ^ 0x3u) + 1) ^ 0x3u);
+    }
+
+    /// Emit the size prefix.
+    inline void EmitSize(size_t Size) {
+      size_t SizeInWords = (Size + 3) / 4;
+      assert(SizeInWords <= 0x100u &&
+             "Only 256 additional words are allowed for unwind opcodes");
+      EmitByte(static_cast<uint8_t>(SizeInWords - 1));
+    }
+
+    /// Emit the personality index prefix.
+    inline void EmitPersonalityIndex(unsigned PI) {
+      assert(PI < ARM::EHABI::NUM_PERSONALITY_INDEX &&
+             "Invalid personality prefix");
+      EmitByte(ARM::EHABI::EHT_COMPACT | PI);
+    }
+
+    /// Fill the rest of bytes with FINISH opcode.
+    inline void FillFinishOpcode() {
+      while (Pos < Vec.size())
+        EmitByte(ARM::EHABI::UNWIND_OPCODE_FINISH);
+    }
+  };
+}
+
+void UnwindOpcodeAssembler::EmitRegSave(uint32_t RegSave) {
+  if (RegSave == 0u)
+    return;
+
+  // One byte opcode to save register r14 and r11-r4
+  if (RegSave & (1u << 4)) {
+    // The one byte opcode will always save r4, thus we can't use the one byte
+    // opcode when r4 is not in .save directive.
+
+    // Compute the consecutive registers from r4 to r11.
+    uint32_t Mask = RegSave & 0xff0u;
+    uint32_t Range = countTrailingOnes(Mask >> 5); // Exclude r4.
+    // Mask off non-consecutive registers. Keep r4.
+    Mask &= ~(0xffffffe0u << Range);
+
+    // Emit this opcode when the mask covers every registers.
+    uint32_t UnmaskedReg = RegSave & 0xfff0u & (~Mask);
+    if (UnmaskedReg == 0u) {
+      // Pop r[4 : (4 + n)]
+      EmitInt8(ARM::EHABI::UNWIND_OPCODE_POP_REG_RANGE_R4 | Range);
+      RegSave &= 0x000fu;
+    } else if (UnmaskedReg == (1u << 14)) {
+      // Pop r[14] + r[4 : (4 + n)]
+      EmitInt8(ARM::EHABI::UNWIND_OPCODE_POP_REG_RANGE_R4_R14 | Range);
+      RegSave &= 0x000fu;
+    }
+  }
+
+  // Two bytes opcode to save register r15-r4
+  if ((RegSave & 0xfff0u) != 0)
+    EmitInt16(ARM::EHABI::UNWIND_OPCODE_POP_REG_MASK_R4 | (RegSave >> 4));
+
+  // Opcode to save register r3-r0
+  if ((RegSave & 0x000fu) != 0)
+    EmitInt16(ARM::EHABI::UNWIND_OPCODE_POP_REG_MASK | (RegSave & 0x000fu));
+}
+
+/// Emit unwind opcodes for .vsave directives
+void UnwindOpcodeAssembler::EmitVFPRegSave(uint32_t VFPRegSave) {
+  // We only have 4 bits to save the offset in the opcode so look at the lower
+  // and upper 16 bits separately.
+  for (uint32_t Regs : {VFPRegSave & 0xffff0000u, VFPRegSave & 0x0000ffffu}) {
+    while (Regs) {
+      // Now look for a run of set bits. Remember the MSB and LSB of the run.
+      auto RangeMSB = 32 - countLeadingZeros(Regs);
+      auto RangeLen = countLeadingOnes(Regs << (32 - RangeMSB));
+      auto RangeLSB = RangeMSB - RangeLen;
+
+      int Opcode = RangeLSB >= 16
+                       ? ARM::EHABI::UNWIND_OPCODE_POP_VFP_REG_RANGE_FSTMFDD_D16
+                       : ARM::EHABI::UNWIND_OPCODE_POP_VFP_REG_RANGE_FSTMFDD;
+
+      EmitInt16(Opcode | ((RangeLSB % 16) << 4) | (RangeLen - 1));
+
+      // Zero out bits we're done with.
+      Regs &= ~(-1u << RangeLSB);
+    }
+  }
+}
+
+/// Emit unwind opcodes to copy address from source register to $sp.
+void UnwindOpcodeAssembler::EmitSetSP(uint16_t Reg) {
+  EmitInt8(ARM::EHABI::UNWIND_OPCODE_SET_VSP | Reg);
+}
+
+/// Emit unwind opcodes to add $sp with an offset.
+void UnwindOpcodeAssembler::EmitSPOffset(int64_t Offset) {
+  if (Offset > 0x200) {
+    uint8_t Buff[16];
+    Buff[0] = ARM::EHABI::UNWIND_OPCODE_INC_VSP_ULEB128;
+    size_t ULEBSize = encodeULEB128((Offset - 0x204) >> 2, Buff + 1);
+    EmitBytes(Buff, ULEBSize + 1);
+  } else if (Offset > 0) {
+    if (Offset > 0x100) {
+      EmitInt8(ARM::EHABI::UNWIND_OPCODE_INC_VSP | 0x3fu);
+      Offset -= 0x100;
+    }
+    EmitInt8(ARM::EHABI::UNWIND_OPCODE_INC_VSP |
+             static_cast<uint8_t>((Offset - 4) >> 2));
+  } else if (Offset < 0) {
+    while (Offset < -0x100) {
+      EmitInt8(ARM::EHABI::UNWIND_OPCODE_DEC_VSP | 0x3fu);
+      Offset += 0x100;
+    }
+    EmitInt8(ARM::EHABI::UNWIND_OPCODE_DEC_VSP |
+             static_cast<uint8_t>(((-Offset) - 4) >> 2));
+  }
+}
+
+void UnwindOpcodeAssembler::Finalize(unsigned &PersonalityIndex,
+                                     SmallVectorImpl<uint8_t> &Result) {
+
+  UnwindOpcodeStreamer OpStreamer(Result);
+
+  if (HasPersonality) {
+    // User-specifed personality routine: [ SIZE , OP1 , OP2 , ... ]
+    PersonalityIndex = ARM::EHABI::NUM_PERSONALITY_INDEX;
+    size_t TotalSize = Ops.size() + 1;
+    size_t RoundUpSize = (TotalSize + 3) / 4 * 4;
+    Result.resize(RoundUpSize);
+    OpStreamer.EmitSize(RoundUpSize);
+  } else {
+    // If no personalityindex is specified, select ane
+    if (PersonalityIndex == ARM::EHABI::NUM_PERSONALITY_INDEX)
+      PersonalityIndex = (Ops.size() <= 3) ? ARM::EHABI::AEABI_UNWIND_CPP_PR0
+                                           : ARM::EHABI::AEABI_UNWIND_CPP_PR1;
+    if (PersonalityIndex == ARM::EHABI::AEABI_UNWIND_CPP_PR0) {
+      // __aeabi_unwind_cpp_pr0: [ 0x80 , OP1 , OP2 , OP3 ]
+      assert(Ops.size() <= 3 && "too many opcodes for __aeabi_unwind_cpp_pr0");
+      Result.resize(4);
+      OpStreamer.EmitPersonalityIndex(PersonalityIndex);
+    } else {
+      // __aeabi_unwind_cpp_pr{1,2}: [ {0x81,0x82} , SIZE , OP1 , OP2 , ... ]
+      size_t TotalSize = Ops.size() + 2;
+      size_t RoundUpSize = (TotalSize + 3) / 4 * 4;
+      Result.resize(RoundUpSize);
+      OpStreamer.EmitPersonalityIndex(PersonalityIndex);
+      OpStreamer.EmitSize(RoundUpSize);
+    }
+  }
+
+  // Copy the unwind opcodes
+  for (size_t i = OpBegins.size() - 1; i > 0; --i)
+    for (size_t j = OpBegins[i - 1], end = OpBegins[i]; j < end; ++j)
+      OpStreamer.EmitByte(Ops[j]);
+
+  // Emit the padding finish opcodes if the size is not multiple of 4.
+  OpStreamer.FillFinishOpcode();
+
+  // Reset the assembler state
+  Reset();
+}