Add support for long-to-double in the optimizing compiler.

- Add support for the long-to-double Dex instruction in the
  optimizing compiler.
- Enable requests of temporary FPU (double) registers during
  code generation.
- Fix art::x86::X86Assembler::LoadLongConstant and extend
  it to int64_t values.
- Have art::x86_64::X86_64Assembler::cvtsi2sd work with
  64-bit operands.
- Generate x86, x86-64 and ARM (but not ARM64) code for
  long to double HTypeConversion nodes.
- Add related tests to test/422-type-conversion.

Change-Id: Ie73d9e5e25bd2e15f585c371e8fc2dcb83438ccd
diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index b261460..35360fe 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -1034,6 +1034,11 @@
       break;
     }
 
+    case Instruction::LONG_TO_DOUBLE: {
+      Conversion_12x(instruction, Primitive::kPrimLong, Primitive::kPrimDouble);
+      break;
+    }
+
     case Instruction::INT_TO_BYTE: {
       Conversion_12x(instruction, Primitive::kPrimInt, Primitive::kPrimByte);
       break;
diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index 0b59327..6cacd4f 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -228,7 +228,8 @@
       DCHECK(!blocked_fpu_registers_[loc.reg()]);
       blocked_fpu_registers_[loc.reg()] = true;
     } else {
-      DCHECK_EQ(loc.GetPolicy(), Location::kRequiresRegister);
+      DCHECK(loc.GetPolicy() == Location::kRequiresRegister
+             || loc.GetPolicy() == Location::kRequiresFpuRegister);
     }
   }
 
@@ -259,10 +260,21 @@
   for (size_t i = 0, e = locations->GetTempCount(); i < e; ++i) {
     Location loc = locations->GetTemp(i);
     if (loc.IsUnallocated()) {
-      DCHECK_EQ(loc.GetPolicy(), Location::kRequiresRegister);
-      // TODO: Adjust handling of temps. We currently consider temps to use
-      // core registers. They may also use floating point registers at some point.
-      loc = AllocateFreeRegister(Primitive::kPrimInt);
+      switch (loc.GetPolicy()) {
+        case Location::kRequiresRegister:
+          // Allocate a core register (large enough to fit a 32-bit integer).
+          loc = AllocateFreeRegister(Primitive::kPrimInt);
+          break;
+
+        case Location::kRequiresFpuRegister:
+          // Allocate a core register (large enough to fit a 64-bit double).
+          loc = AllocateFreeRegister(Primitive::kPrimDouble);
+          break;
+
+        default:
+          LOG(FATAL) << "Unexpected policy for temporary location "
+                     << loc.GetPolicy();
+      }
       locations->SetTempAt(i, loc);
     }
   }
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 890cfdd..22a8590 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -1481,6 +1481,14 @@
           break;
 
         case Primitive::kPrimLong:
+          // Processing a Dex `long-to-double' instruction.
+          locations->SetInAt(0, Location::RequiresRegister());
+          locations->SetOut(Location::RequiresFpuRegister());
+          locations->AddTemp(Location::RequiresRegister());
+          locations->AddTemp(Location::RequiresRegister());
+          locations->AddTemp(Location::RequiresFpuRegister());
+          break;
+
         case Primitive::kPrimFloat:
           LOG(FATAL) << "Type conversion from " << input_type
                      << " to " << result_type << " not yet implemented";
@@ -1645,7 +1653,41 @@
           break;
         }
 
-        case Primitive::kPrimLong:
+        case Primitive::kPrimLong: {
+          // Processing a Dex `long-to-double' instruction.
+          Register low = in.AsRegisterPairLow<Register>();
+          Register high = in.AsRegisterPairHigh<Register>();
+          SRegister out_s = out.AsFpuRegisterPairLow<SRegister>();
+          DRegister out_d = FromLowSToD(out_s);
+          Register constant_low = locations->GetTemp(0).As<Register>();
+          Register constant_high = locations->GetTemp(1).As<Register>();
+          SRegister temp_s = locations->GetTemp(2).AsFpuRegisterPairLow<SRegister>();
+          DRegister temp_d = FromLowSToD(temp_s);
+
+          // Binary encoding of 2^32 for type double.
+          const uint64_t c = UINT64_C(0x41F0000000000000);
+
+          // out_d = int-to-double(high)
+          __ vmovsr(out_s, high);
+          __ vcvtdi(out_d, out_s);
+          // Using vmovd to load the `c` constant as an immediate
+          // value into `temp_d` does not work, as this instruction
+          // only transfers 8 significant bits of its immediate
+          // operand.  Instead, use two 32-bit core registers to
+          // load `c` into `temp_d`.
+          __ LoadImmediate(constant_low, Low32Bits(c));
+          __ LoadImmediate(constant_high, High32Bits(c));
+          __ vmovdrr(temp_d, constant_low, constant_high);
+          // out_d = out_d * 2^32
+          __ vmuld(out_d, out_d, temp_d);
+          // temp_d = unsigned-to-double(low)
+          __ vmovsr(temp_s, low);
+          __ vcvtdu(temp_d, temp_s);
+          // out_d = out_d + temp_d
+          __ vaddd(out_d, out_d, temp_d);
+          break;
+        }
+
         case Primitive::kPrimFloat:
           LOG(FATAL) << "Type conversion from " << input_type
                      << " to " << result_type << " not yet implemented";
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 3689452..c482885 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -1429,6 +1429,13 @@
           break;
 
         case Primitive::kPrimLong:
+          // Processing a Dex `long-to-double' instruction.
+          locations->SetInAt(0, Location::RequiresRegister());
+          locations->SetOut(Location::RequiresFpuRegister());
+          locations->AddTemp(Location::RequiresFpuRegister());
+          locations->AddTemp(Location::RequiresFpuRegister());
+          break;
+
         case Primitive::kPrimFloat:
           LOG(FATAL) << "Type conversion from " << input_type
                      << " to " << result_type << " not yet implemented";
@@ -1608,7 +1615,37 @@
           __ cvtsi2sd(out.As<XmmRegister>(), in.As<Register>());
           break;
 
-        case Primitive::kPrimLong:
+        case Primitive::kPrimLong: {
+          // Processing a Dex `long-to-double' instruction.
+          Register low = in.AsRegisterPairLow<Register>();
+          Register high = in.AsRegisterPairHigh<Register>();
+          XmmRegister result = out.As<XmmRegister>();
+          XmmRegister temp = locations->GetTemp(0).As<XmmRegister>();
+          XmmRegister constant = locations->GetTemp(1).As<XmmRegister>();
+
+          // Binary encoding of 2^32 for type double.
+          const int64_t c1 = INT64_C(0x41F0000000000000);
+          // Binary encoding of 2^31 for type double.
+          const int64_t c2 = INT64_C(0x41E0000000000000);
+
+          // low = low - 2^31 (to prevent bit 31 of `low` to be
+          // interpreted as a sign bit)
+          __ subl(low, Immediate(0x80000000));
+          // temp = int-to-double(high)
+          __ cvtsi2sd(temp, high);
+          // temp = temp * 2^32
+          __ LoadLongConstant(constant, c1);
+          __ mulsd(temp, constant);
+          // result = int-to-double(low)
+          __ cvtsi2sd(result, low);
+          // result = result + 2^31 (restore the original value of `low`)
+          __ LoadLongConstant(constant, c2);
+          __ addsd(result, constant);
+          // result = result + temp
+          __ addsd(result, temp);
+          break;
+        }
+
         case Primitive::kPrimFloat:
           LOG(FATAL) << "Type conversion from " << input_type
                      << " to " << result_type << " not yet implemented";
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 34fa1e7..63938f3 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -1430,6 +1430,11 @@
           break;
 
         case Primitive::kPrimLong:
+          // Processing a Dex `long-to-double' instruction.
+          locations->SetInAt(0, Location::RequiresRegister());
+          locations->SetOut(Location::RequiresFpuRegister());
+          break;
+
         case Primitive::kPrimFloat:
           LOG(FATAL) << "Type conversion from " << input_type
                      << " to " << result_type << " not yet implemented";
@@ -1609,10 +1614,14 @@
         case Primitive::kPrimShort:
         case Primitive::kPrimInt:
         case Primitive::kPrimChar:
-          __ cvtsi2sd(out.As<XmmRegister>(), in.As<CpuRegister>());
+          __ cvtsi2sd(out.As<XmmRegister>(), in.As<CpuRegister>(), false);
           break;
 
         case Primitive::kPrimLong:
+          // Processing a Dex `long-to-double' instruction.
+          __ cvtsi2sd(out.As<XmmRegister>(), in.As<CpuRegister>(), true);
+          break;
+
         case Primitive::kPrimFloat:
           LOG(FATAL) << "Type conversion from " << input_type
                      << " to " << result_type << " not yet implemented";
diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index a297ea3..dbad386 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -1318,13 +1318,19 @@
 }
 
 
+void X86Assembler::LoadLongConstant(XmmRegister dst, int64_t value) {
+  // TODO: Need to have a code constants table.
+  pushl(Immediate(High32Bits(value)));
+  pushl(Immediate(Low32Bits(value)));
+  movsd(dst, Address(ESP, 0));
+  addl(ESP, Immediate(2 * sizeof(int32_t)));
+}
+
+
 void X86Assembler::LoadDoubleConstant(XmmRegister dst, double value) {
   // TODO: Need to have a code constants table.
   int64_t constant = bit_cast<int64_t, double>(value);
-  pushl(Immediate(High32Bits(constant)));
-  pushl(Immediate(Low32Bits(constant)));
-  movsd(dst, Address(ESP, 0));
-  addl(ESP, Immediate(2 * sizeof(intptr_t)));
+  LoadLongConstant(dst, constant);
 }
 
 
diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index 6ea66a5..0d82487 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -42,8 +42,6 @@
 
  private:
   const int32_t value_;
-
-  DISALLOW_COPY_AND_ASSIGN(Immediate);
 };
 
 
@@ -441,6 +439,7 @@
 
   void AddImmediate(Register reg, const Immediate& imm);
 
+  void LoadLongConstant(XmmRegister dst, int64_t value);
   void LoadDoubleConstant(XmmRegister dst, double value);
 
   void DoubleNegate(XmmRegister d);
diff --git a/compiler/utils/x86/assembler_x86_test.cc b/compiler/utils/x86/assembler_x86_test.cc
index 5d8a3b1..d901673 100644
--- a/compiler/utils/x86/assembler_x86_test.cc
+++ b/compiler/utils/x86/assembler_x86_test.cc
@@ -16,7 +16,8 @@
 
 #include "assembler_x86.h"
 
-#include "gtest/gtest.h"
+#include "base/stl_util.h"
+#include "utils/assembler_test.h"
 
 namespace art {
 
@@ -29,4 +30,89 @@
   ASSERT_EQ(static_cast<size_t>(5), buffer.Size());
 }
 
+class AssemblerX86Test : public AssemblerTest<x86::X86Assembler, x86::Register,
+                                              x86::XmmRegister, x86::Immediate> {
+ protected:
+  std::string GetArchitectureString() OVERRIDE {
+    return "x86";
+  }
+
+  std::string GetAssemblerParameters() OVERRIDE {
+    return " --32";
+  }
+
+  std::string GetDisassembleParameters() OVERRIDE {
+    return " -D -bbinary -mi386 --no-show-raw-insn";
+  }
+
+  void SetUpHelpers() OVERRIDE {
+    if (registers_.size() == 0) {
+      registers_.insert(end(registers_),
+                        {  // NOLINT(whitespace/braces)
+                          new x86::Register(x86::EAX),
+                          new x86::Register(x86::EBX),
+                          new x86::Register(x86::ECX),
+                          new x86::Register(x86::EDX),
+                          new x86::Register(x86::EBP),
+                          new x86::Register(x86::ESP),
+                          new x86::Register(x86::ESI),
+                          new x86::Register(x86::EDI)
+                        });
+    }
+
+    if (fp_registers_.size() == 0) {
+      fp_registers_.insert(end(fp_registers_),
+                           {  // NOLINT(whitespace/braces)
+                             new x86::XmmRegister(x86::XMM0),
+                             new x86::XmmRegister(x86::XMM1),
+                             new x86::XmmRegister(x86::XMM2),
+                             new x86::XmmRegister(x86::XMM3),
+                             new x86::XmmRegister(x86::XMM4),
+                             new x86::XmmRegister(x86::XMM5),
+                             new x86::XmmRegister(x86::XMM6),
+                             new x86::XmmRegister(x86::XMM7)
+                           });
+    }
+  }
+
+  void TearDown() OVERRIDE {
+    AssemblerTest::TearDown();
+    STLDeleteElements(&registers_);
+    STLDeleteElements(&fp_registers_);
+  }
+
+  std::vector<x86::Register*> GetRegisters() OVERRIDE {
+    return registers_;
+  }
+
+  std::vector<x86::XmmRegister*> GetFPRegisters() OVERRIDE {
+    return fp_registers_;
+  }
+
+  x86::Immediate CreateImmediate(int64_t imm_value) OVERRIDE {
+    return x86::Immediate(imm_value);
+  }
+
+ private:
+  std::vector<x86::Register*> registers_;
+  std::vector<x86::XmmRegister*> fp_registers_;
+};
+
+
+TEST_F(AssemblerX86Test, Movl) {
+  GetAssembler()->movl(x86::EAX, x86::EBX);
+  const char* expected = "mov %ebx, %eax\n";
+  DriverStr(expected, "movl");
+}
+
+TEST_F(AssemblerX86Test, LoadLongConstant) {
+  GetAssembler()->LoadLongConstant(x86::XMM0, 51);
+  const char* expected =
+      "push $0x0\n"
+      "push $0x33\n"
+      "movsd 0(%esp), %xmm0\n"
+      "add $8, %esp\n";
+  DriverStr(expected, "LoadLongConstant");
+}
+
 }  // namespace art
diff --git a/compiler/utils/x86_64/assembler_x86_64.cc b/compiler/utils/x86_64/assembler_x86_64.cc
index dff3849..381ee33 100644
--- a/compiler/utils/x86_64/assembler_x86_64.cc
+++ b/compiler/utils/x86_64/assembler_x86_64.cc
@@ -603,9 +603,19 @@
 
 
 void X86_64Assembler::cvtsi2sd(XmmRegister dst, CpuRegister src) {
+  cvtsi2sd(dst, src, false);
+}
+
+
+void X86_64Assembler::cvtsi2sd(XmmRegister dst, CpuRegister src, bool is64bit) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xF2);
-  EmitOptionalRex32(dst, src);
+  if (is64bit) {
+    // Emit a REX.W prefix if the operand size is 64 bits.
+    EmitRex64(dst, src);
+  } else {
+    EmitOptionalRex32(dst, src);
+  }
   EmitUint8(0x0F);
   EmitUint8(0x2A);
   EmitOperand(dst.LowBits(), Operand(src));
diff --git a/compiler/utils/x86_64/assembler_x86_64.h b/compiler/utils/x86_64/assembler_x86_64.h
index ab1bc9e..9f31818 100644
--- a/compiler/utils/x86_64/assembler_x86_64.h
+++ b/compiler/utils/x86_64/assembler_x86_64.h
@@ -330,6 +330,7 @@
 
   void cvtsi2ss(XmmRegister dst, CpuRegister src);  // Note: this is the r/m32 version.
   void cvtsi2sd(XmmRegister dst, CpuRegister src);  // Note: this is the r/m32 version.
+  void cvtsi2sd(XmmRegister dst, CpuRegister src, bool is64bit);
 
   void cvtss2si(CpuRegister dst, XmmRegister src);  // Note: this is the r32 version.
   void cvtss2sd(XmmRegister dst, XmmRegister src);