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/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_COMPILER_DEX_REG_STORAGE_H_
#define ART_COMPILER_DEX_REG_STORAGE_H_
#include "base/logging.h"
#include "compiler_enums.h" // For WideKind
namespace art {
/*
* 16-bit representation of the physical register container holding a Dalvik value.
* The encoding allows up to 64 physical elements per storage class, and supports eight
* register container shapes.
*
* [V] [HHHHH] [SSS] [F] [LLLLLL]
*
* [LLLLLL]
* Physical register number for the low or solo register.
* 0..63
*
* [F]
* Describes type of the [LLLLL] register.
* 0: Core
* 1: Floating point
*
* [SSS]
* Shape of the register container.
* 000: Invalid
* 001: 32-bit solo register
* 010: 64-bit solo register
* 011: 64-bit pair consisting of two 32-bit solo registers
* 100: 128-bit solo register
* 101: 256-bit solo register
* 110: 512-bit solo register
* 111: 1024-bit solo register
*
* [HHHHH]
* Physical register number of the high register (valid only for register pair).
* 0..31
*
* [V]
* 0 -> Invalid
* 1 -> Valid
*
* Note that in all non-invalid cases, we can determine if the storage is floating point
* by testing bit 7. Note also that a register pair is effectively limited to a pair of
* physical register numbers in the 0..31 range.
*
* On some target architectures, the same underlying physical register container can be given
* different views. For example, Arm's 32-bit single-precision floating point registers
* s2 and s3 map to the low and high halves of double-precision d1. Similarly, X86's xmm3
* vector register can be viewed as 32-bit, 64-bit, 128-bit, etc. In these cases the use of
* one view will affect the other views. The RegStorage class does not concern itself
* with potential aliasing. That will be done using the associated RegisterInfo struct.
* Distinct RegStorage elements should be created for each view of a physical register
* container. The management of the aliased physical elements will be handled via RegisterInfo
* records.
*/
class RegStorage {
public:
enum RegStorageKind {
kValidMask = 0x8000,
kValid = 0x8000,
kInvalid = 0x0000,
kShapeMask = 0x0380,
k32BitSolo = 0x0080,
k64BitSolo = 0x0100,
k64BitPair = 0x0180,
k128BitSolo = 0x0200,
k256BitSolo = 0x0280,
k512BitSolo = 0x0300,
k1024BitSolo = 0x0380,
k64BitMask = 0x0300,
k64Bits = 0x0100,
kShapeTypeMask = 0x03c0,
kFloatingPoint = 0x0040,
kCoreRegister = 0x0000,
};
static const uint16_t kRegValMask = 0x03ff; // Num, type and shape.
static const uint16_t kRegTypeMask = 0x007f; // Num and type.
static const uint16_t kRegNumMask = 0x003f; // Num only.
static const uint16_t kHighRegNumMask = 0x001f; // 0..31 for high reg
static const uint16_t kMaxRegs = kRegValMask + 1;
// TODO: deprecate use of kInvalidRegVal and speed up GetReg(). Rely on valid bit instead.
static const uint16_t kInvalidRegVal = 0x03ff;
static const uint16_t kHighRegShift = 10;
static const uint16_t kHighRegMask = (kHighRegNumMask << kHighRegShift);
// Reg is [F][LLLLL], will override any existing shape and use rs_kind.
constexpr RegStorage(RegStorageKind rs_kind, int reg)
: reg_(
DCHECK_CONSTEXPR(rs_kind != k64BitPair, , 0u)
DCHECK_CONSTEXPR((rs_kind & ~kShapeMask) == 0, , 0u)
kValid | rs_kind | (reg & kRegTypeMask)) {
}
constexpr RegStorage(RegStorageKind rs_kind, int low_reg, int high_reg)
: reg_(
DCHECK_CONSTEXPR(rs_kind == k64BitPair, << rs_kind, 0u)
DCHECK_CONSTEXPR((low_reg & kFloatingPoint) == (high_reg & kFloatingPoint),
<< low_reg << ", " << high_reg, 0u)
DCHECK_CONSTEXPR((high_reg & kRegNumMask) <= kHighRegNumMask,
<< "High reg must be in 0..31: " << high_reg, false)
kValid | rs_kind | ((high_reg & kHighRegNumMask) << kHighRegShift) |
(low_reg & kRegTypeMask)) {
}
constexpr explicit RegStorage(uint16_t val) : reg_(val) {}
RegStorage() : reg_(kInvalid) {}
// We do not provide a general operator overload for equality of reg storage, as this is
// dangerous in the case of architectures with multiple views, and the naming ExactEquals
// expresses the exact match expressed here. It is more likely that a comparison between the views
// is intended in most cases. Such code can be found in, for example, Mir2Lir::IsSameReg.
//
// If you know what you are doing, include reg_storage_eq.h, which defines == and != for brevity.
bool ExactlyEquals(const RegStorage& rhs) const {
return (reg_ == rhs.GetRawBits());
}
bool NotExactlyEquals(const RegStorage& rhs) const {
return (reg_ != rhs.GetRawBits());
}
constexpr bool Valid() const {
return ((reg_ & kValidMask) == kValid);
}
constexpr bool Is32Bit() const {
return ((reg_ & kShapeMask) == k32BitSolo);
}
constexpr bool Is64Bit() const {
return ((reg_ & k64BitMask) == k64Bits);
}
constexpr WideKind GetWideKind() const {
return Is64Bit() ? kWide : kNotWide;
}
constexpr bool Is64BitSolo() const {
return ((reg_ & kShapeMask) == k64BitSolo);
}
constexpr bool IsPair() const {
return ((reg_ & kShapeMask) == k64BitPair);
}
constexpr bool IsFloat() const {
return
DCHECK_CONSTEXPR(Valid(), , false)
((reg_ & kFloatingPoint) == kFloatingPoint);
}
constexpr bool IsDouble() const {
return
DCHECK_CONSTEXPR(Valid(), , false)
(reg_ & (kFloatingPoint | k64BitMask)) == (kFloatingPoint | k64Bits);
}
constexpr bool IsSingle() const {
return
DCHECK_CONSTEXPR(Valid(), , false)
(reg_ & (kFloatingPoint | k64BitMask)) == kFloatingPoint;
}
static constexpr bool IsFloat(uint16_t reg) {
return ((reg & kFloatingPoint) == kFloatingPoint);
}
static constexpr bool IsDouble(uint16_t reg) {
return (reg & (kFloatingPoint | k64BitMask)) == (kFloatingPoint | k64Bits);
}
static constexpr bool IsSingle(uint16_t reg) {
return (reg & (kFloatingPoint | k64BitMask)) == kFloatingPoint;
}
// Used to retrieve either the low register of a pair, or the only register.
int GetReg() const {
DCHECK(!IsPair()) << "reg_ = 0x" << std::hex << reg_;
return Valid() ? (reg_ & kRegValMask) : kInvalidRegVal;
}
// Sets shape, type and num of solo.
void SetReg(int reg) {
DCHECK(Valid());
DCHECK(!IsPair());
reg_ = (reg_ & ~kRegValMask) | reg;
}
// Set the reg number and type only, target remain 64-bit pair.
void SetLowReg(int reg) {
DCHECK(IsPair());
reg_ = (reg_ & ~kRegTypeMask) | (reg & kRegTypeMask);
}
// Retrieve the least significant register of a pair and return as 32-bit solo.
int GetLowReg() const {
DCHECK(IsPair());
return ((reg_ & kRegTypeMask) | k32BitSolo);
}
// Create a stand-alone RegStorage from the low reg of a pair.
RegStorage GetLow() const {
DCHECK(IsPair());
return RegStorage(k32BitSolo, reg_ & kRegTypeMask);
}
// Retrieve the most significant register of a pair.
int GetHighReg() const {
DCHECK(IsPair());
return k32BitSolo | ((reg_ & kHighRegMask) >> kHighRegShift) | (reg_ & kFloatingPoint);
}
// Create a stand-alone RegStorage from the high reg of a pair.
RegStorage GetHigh() const {
DCHECK(IsPair());
return RegStorage(kValid | GetHighReg());
}
void SetHighReg(int reg) {
DCHECK(IsPair());
reg_ = (reg_ & ~kHighRegMask) | ((reg & kHighRegNumMask) << kHighRegShift);
}
// Return the register number of low or solo.
constexpr int GetRegNum() const {
return reg_ & kRegNumMask;
}
// Is register number in 0..7?
constexpr bool Low8() const {
return GetRegNum() < 8;
}
// Is register number in 0..3?
constexpr bool Low4() const {
return GetRegNum() < 4;
}
// Combine 2 32-bit solo regs into a pair.
static RegStorage MakeRegPair(RegStorage low, RegStorage high) {
DCHECK(!low.IsPair());
DCHECK(low.Is32Bit());
DCHECK(!high.IsPair());
DCHECK(high.Is32Bit());
return RegStorage(k64BitPair, low.GetReg(), high.GetReg());
}
static constexpr bool SameRegType(RegStorage reg1, RegStorage reg2) {
return (reg1.IsDouble() == reg2.IsDouble()) && (reg1.IsSingle() == reg2.IsSingle());
}
static constexpr bool SameRegType(int reg1, int reg2) {
return (IsDouble(reg1) == IsDouble(reg2)) && (IsSingle(reg1) == IsSingle(reg2));
}
// Create a 32-bit solo.
static RegStorage Solo32(int reg_num) {
return RegStorage(k32BitSolo, reg_num & kRegTypeMask);
}
// Create a floating point 32-bit solo.
static constexpr RegStorage FloatSolo32(int reg_num) {
return RegStorage(k32BitSolo, (reg_num & kRegNumMask) | kFloatingPoint);
}
// Create a 128-bit solo.
static constexpr RegStorage Solo128(int reg_num) {
return RegStorage(k128BitSolo, reg_num & kRegTypeMask);
}
// Create a 64-bit solo.
static constexpr RegStorage Solo64(int reg_num) {
return RegStorage(k64BitSolo, reg_num & kRegTypeMask);
}
// Create a floating point 64-bit solo.
static RegStorage FloatSolo64(int reg_num) {
return RegStorage(k64BitSolo, (reg_num & kRegNumMask) | kFloatingPoint);
}
static constexpr RegStorage InvalidReg() {
return RegStorage(kInvalid);
}
static constexpr uint16_t RegNum(int raw_reg_bits) {
return raw_reg_bits & kRegNumMask;
}
constexpr int GetRawBits() const {
return reg_;
}
size_t StorageSize() const {
switch (reg_ & kShapeMask) {
case kInvalid: return 0;
case k32BitSolo: return 4;
case k64BitSolo: return 8;
case k64BitPair: return 8; // Is this useful? Might want to disallow taking size of pair.
case k128BitSolo: return 16;
case k256BitSolo: return 32;
case k512BitSolo: return 64;
case k1024BitSolo: return 128;
default: LOG(FATAL) << "Unexpected shape";
}
return 0;
}
private:
uint16_t reg_;
};
} // namespace art
#endif // ART_COMPILER_DEX_REG_STORAGE_H_