Merge experimental/a64 to bleeding_edge.

src/a64/instructions-a64.cc

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "v8.h"
+
+#if V8_TARGET_ARCH_A64
+
+#define A64_DEFINE_FP_STATICS
+
+#include "a64/instructions-a64.h"
+#include "a64/assembler-a64-inl.h"
+
+namespace v8 {
+namespace internal {
+
+
+bool Instruction::IsLoad() const {
+  if (Mask(LoadStoreAnyFMask) != LoadStoreAnyFixed) {
+    return false;
+  }
+
+  if (Mask(LoadStorePairAnyFMask) == LoadStorePairAnyFixed) {
+    return Mask(LoadStorePairLBit) != 0;
+  } else {
+    LoadStoreOp op = static_cast<LoadStoreOp>(Mask(LoadStoreOpMask));
+    switch (op) {
+      case LDRB_w:
+      case LDRH_w:
+      case LDR_w:
+      case LDR_x:
+      case LDRSB_w:
+      case LDRSB_x:
+      case LDRSH_w:
+      case LDRSH_x:
+      case LDRSW_x:
+      case LDR_s:
+      case LDR_d: return true;
+      default: return false;
+    }
+  }
+}
+
+
+bool Instruction::IsStore() const {
+  if (Mask(LoadStoreAnyFMask) != LoadStoreAnyFixed) {
+    return false;
+  }
+
+  if (Mask(LoadStorePairAnyFMask) == LoadStorePairAnyFixed) {
+    return Mask(LoadStorePairLBit) == 0;
+  } else {
+    LoadStoreOp op = static_cast<LoadStoreOp>(Mask(LoadStoreOpMask));
+    switch (op) {
+      case STRB_w:
+      case STRH_w:
+      case STR_w:
+      case STR_x:
+      case STR_s:
+      case STR_d: return true;
+      default: return false;
+    }
+  }
+}
+
+
+static uint64_t RotateRight(uint64_t value,
+                            unsigned int rotate,
+                            unsigned int width) {
+  ASSERT(width <= 64);
+  rotate &= 63;
+  return ((value & ((1UL << rotate) - 1UL)) << (width - rotate)) |
+         (value >> rotate);
+}
+
+
+static uint64_t RepeatBitsAcrossReg(unsigned reg_size,
+                                    uint64_t value,
+                                    unsigned width) {
+  ASSERT((width == 2) || (width == 4) || (width == 8) || (width == 16) ||
+         (width == 32));
+  ASSERT((reg_size == kWRegSize) || (reg_size == kXRegSize));
+  uint64_t result = value & ((1UL << width) - 1UL);
+  for (unsigned i = width; i < reg_size; i *= 2) {
+    result |= (result << i);
+  }
+  return result;
+}
+
+
+// Logical immediates can't encode zero, so a return value of zero is used to
+// indicate a failure case. Specifically, where the constraints on imm_s are not
+// met.
+uint64_t Instruction::ImmLogical() {
+  unsigned reg_size = SixtyFourBits() ? kXRegSize : kWRegSize;
+  int64_t n = BitN();
+  int64_t imm_s = ImmSetBits();
+  int64_t imm_r = ImmRotate();
+
+  // An integer is constructed from the n, imm_s and imm_r bits according to
+  // the following table:
+  //
+  //  N   imms    immr    size        S             R
+  //  1  ssssss  rrrrrr    64    UInt(ssssss)  UInt(rrrrrr)
+  //  0  0sssss  xrrrrr    32    UInt(sssss)   UInt(rrrrr)
+  //  0  10ssss  xxrrrr    16    UInt(ssss)    UInt(rrrr)
+  //  0  110sss  xxxrrr     8    UInt(sss)     UInt(rrr)
+  //  0  1110ss  xxxxrr     4    UInt(ss)      UInt(rr)
+  //  0  11110s  xxxxxr     2    UInt(s)       UInt(r)
+  // (s bits must not be all set)
+  //
+  // A pattern is constructed of size bits, where the least significant S+1
+  // bits are set. The pattern is rotated right by R, and repeated across a
+  // 32 or 64-bit value, depending on destination register width.
+  //
+
+  if (n == 1) {
+    if (imm_s == 0x3F) {
+      return 0;
+    }
+    uint64_t bits = (1UL << (imm_s + 1)) - 1;
+    return RotateRight(bits, imm_r, 64);
+  } else {
+    if ((imm_s >> 1) == 0x1F) {
+      return 0;
+    }
+    for (int width = 0x20; width >= 0x2; width >>= 1) {
+      if ((imm_s & width) == 0) {
+        int mask = width - 1;
+        if ((imm_s & mask) == mask) {
+          return 0;
+        }
+        uint64_t bits = (1UL << ((imm_s & mask) + 1)) - 1;
+        return RepeatBitsAcrossReg(reg_size,
+                                   RotateRight(bits, imm_r & mask, width),
+                                   width);
+      }
+    }
+  }
+  UNREACHABLE();
+  return 0;
+}
+
+
+float Instruction::ImmFP32() {
+  //  ImmFP: abcdefgh (8 bits)
+  // Single: aBbb.bbbc.defg.h000.0000.0000.0000.0000 (32 bits)
+  // where B is b ^ 1
+  uint32_t bits = ImmFP();
+  uint32_t bit7 = (bits >> 7) & 0x1;
+  uint32_t bit6 = (bits >> 6) & 0x1;
+  uint32_t bit5_to_0 = bits & 0x3f;
+  uint32_t result = (bit7 << 31) | ((32 - bit6) << 25) | (bit5_to_0 << 19);
+
+  return rawbits_to_float(result);
+}
+
+
+double Instruction::ImmFP64() {
+  //  ImmFP: abcdefgh (8 bits)
+  // Double: aBbb.bbbb.bbcd.efgh.0000.0000.0000.0000
+  //         0000.0000.0000.0000.0000.0000.0000.0000 (64 bits)
+  // where B is b ^ 1
+  uint32_t bits = ImmFP();
+  uint64_t bit7 = (bits >> 7) & 0x1;
+  uint64_t bit6 = (bits >> 6) & 0x1;
+  uint64_t bit5_to_0 = bits & 0x3f;
+  uint64_t result = (bit7 << 63) | ((256 - bit6) << 54) | (bit5_to_0 << 48);
+
+  return rawbits_to_double(result);
+}
+
+
+LSDataSize CalcLSPairDataSize(LoadStorePairOp op) {
+  switch (op) {
+    case STP_x:
+    case LDP_x:
+    case STP_d:
+    case LDP_d: return LSDoubleWord;
+    default: return LSWord;
+  }
+}
+
+
+ptrdiff_t Instruction::ImmPCOffset() {
+  ptrdiff_t offset;
+  if (IsPCRelAddressing()) {
+    // PC-relative addressing. Only ADR is supported.
+    offset = ImmPCRel();
+  } else if (BranchType() != UnknownBranchType) {
+    // All PC-relative branches.
+    // Relative branch offsets are instruction-size-aligned.
+    offset = ImmBranch() << kInstructionSizeLog2;
+  } else {
+    // Load literal (offset from PC).
+    ASSERT(IsLdrLiteral());
+    // The offset is always shifted by 2 bits, even for loads to 64-bits
+    // registers.
+    offset = ImmLLiteral() << kInstructionSizeLog2;
+  }
+  return offset;
+}
+
+
+Instruction* Instruction::ImmPCOffsetTarget() {
+  return this + ImmPCOffset();
+}
+
+
+void Instruction::SetImmPCOffsetTarget(Instruction* target) {
+  if (IsPCRelAddressing()) {
+    SetPCRelImmTarget(target);
+  } else if (BranchType() != UnknownBranchType) {
+    SetBranchImmTarget(target);
+  } else {
+    SetImmLLiteral(target);
+  }
+}
+
+
+void Instruction::SetPCRelImmTarget(Instruction* target) {
+  // ADRP is not supported, so 'this' must point to an ADR instruction.
+  ASSERT(Mask(PCRelAddressingMask) == ADR);
+
+  Instr imm = Assembler::ImmPCRelAddress(target - this);
+
+  SetInstructionBits(Mask(~ImmPCRel_mask) | imm);
+}
+
+
+void Instruction::SetBranchImmTarget(Instruction* target) {
+  ASSERT(((target - this) & 3) == 0);
+  Instr branch_imm = 0;
+  uint32_t imm_mask = 0;
+  int offset = (target - this) >> kInstructionSizeLog2;
+  switch (BranchType()) {
+    case CondBranchType: {
+      branch_imm = Assembler::ImmCondBranch(offset);
+      imm_mask = ImmCondBranch_mask;
+      break;
+    }
+    case UncondBranchType: {
+      branch_imm = Assembler::ImmUncondBranch(offset);
+      imm_mask = ImmUncondBranch_mask;
+      break;
+    }
+    case CompareBranchType: {
+      branch_imm = Assembler::ImmCmpBranch(offset);
+      imm_mask = ImmCmpBranch_mask;
+      break;
+    }
+    case TestBranchType: {
+      branch_imm = Assembler::ImmTestBranch(offset);
+      imm_mask = ImmTestBranch_mask;
+      break;
+    }
+    default: UNREACHABLE();
+  }
+  SetInstructionBits(Mask(~imm_mask) | branch_imm);
+}
+
+
+void Instruction::SetImmLLiteral(Instruction* source) {
+  ASSERT(((source - this) & 3) == 0);
+  int offset = (source - this) >> kLiteralEntrySizeLog2;
+  Instr imm = Assembler::ImmLLiteral(offset);
+  Instr mask = ImmLLiteral_mask;
+
+  SetInstructionBits(Mask(~mask) | imm);
+}
+
+
+// TODO(jbramley): We can't put this inline in the class because things like
+// xzr and Register are not defined in that header. Consider adding
+// instructions-a64-inl.h to work around this.
+bool InstructionSequence::IsInlineData() const {
+  // Inline data is encoded as a single movz instruction which writes to xzr
+  // (x31).
+  return IsMovz() && SixtyFourBits() && (Rd() == xzr.code());
+  // TODO(all): If we extend ::InlineData() to support bigger data, we need
+  // to update this method too.
+}
+
+
+// TODO(jbramley): We can't put this inline in the class because things like
+// xzr and Register are not defined in that header. Consider adding
+// instructions-a64-inl.h to work around this.
+uint64_t InstructionSequence::InlineData() const {
+  ASSERT(IsInlineData());
+  uint64_t payload = ImmMoveWide();
+  // TODO(all): If we extend ::InlineData() to support bigger data, we need
+  // to update this method too.
+  return payload;
+}
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_TARGET_ARCH_A64