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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /js/src/jit/shared/Assembler-shared.h
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
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diff --git a/js/src/jit/shared/Assembler-shared.h b/js/src/jit/shared/Assembler-shared.h
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+++ b/js/src/jit/shared/Assembler-shared.h
@@ -0,0 +1,991 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef jit_shared_Assembler_shared_h
+#define jit_shared_Assembler_shared_h
+
+#include "mozilla/PodOperations.h"
+
+#include <limits.h>
+
+#include "jit/AtomicOp.h"
+#include "jit/JitAllocPolicy.h"
+#include "jit/Label.h"
+#include "jit/Registers.h"
+#include "jit/RegisterSets.h"
+#include "vm/HelperThreads.h"
+#include "wasm/WasmTypes.h"
+
+#if defined(JS_CODEGEN_ARM) || defined(JS_CODEGEN_ARM64) || \
+ defined(JS_CODEGEN_MIPS32) || defined(JS_CODEGEN_MIPS64)
+// Push return addresses callee-side.
+# define JS_USE_LINK_REGISTER
+#endif
+
+#if defined(JS_CODEGEN_X64) || defined(JS_CODEGEN_ARM) || defined(JS_CODEGEN_ARM64)
+// JS_SMALL_BRANCH means the range on a branch instruction
+// is smaller than the whole address space
+# define JS_SMALL_BRANCH
+#endif
+
+namespace js {
+namespace jit {
+
+namespace Disassembler {
+class HeapAccess;
+} // namespace Disassembler
+
+static const uint32_t Simd128DataSize = 4 * sizeof(int32_t);
+static_assert(Simd128DataSize == 4 * sizeof(int32_t), "SIMD data should be able to contain int32x4");
+static_assert(Simd128DataSize == 4 * sizeof(float), "SIMD data should be able to contain float32x4");
+static_assert(Simd128DataSize == 2 * sizeof(double), "SIMD data should be able to contain float64x2");
+
+enum Scale {
+ TimesOne = 0,
+ TimesTwo = 1,
+ TimesFour = 2,
+ TimesEight = 3
+};
+
+static_assert(sizeof(JS::Value) == 8,
+ "required for TimesEight and 3 below to be correct");
+static const Scale ValueScale = TimesEight;
+static const size_t ValueShift = 3;
+
+static inline unsigned
+ScaleToShift(Scale scale)
+{
+ return unsigned(scale);
+}
+
+static inline bool
+IsShiftInScaleRange(int i)
+{
+ return i >= TimesOne && i <= TimesEight;
+}
+
+static inline Scale
+ShiftToScale(int i)
+{
+ MOZ_ASSERT(IsShiftInScaleRange(i));
+ return Scale(i);
+}
+
+static inline Scale
+ScaleFromElemWidth(int shift)
+{
+ switch (shift) {
+ case 1:
+ return TimesOne;
+ case 2:
+ return TimesTwo;
+ case 4:
+ return TimesFour;
+ case 8:
+ return TimesEight;
+ }
+
+ MOZ_CRASH("Invalid scale");
+}
+
+// Used for 32-bit immediates which do not require relocation.
+struct Imm32
+{
+ int32_t value;
+
+ explicit Imm32(int32_t value) : value(value)
+ { }
+
+ static inline Imm32 ShiftOf(enum Scale s) {
+ switch (s) {
+ case TimesOne:
+ return Imm32(0);
+ case TimesTwo:
+ return Imm32(1);
+ case TimesFour:
+ return Imm32(2);
+ case TimesEight:
+ return Imm32(3);
+ };
+ MOZ_CRASH("Invalid scale");
+ }
+
+ static inline Imm32 FactorOf(enum Scale s) {
+ return Imm32(1 << ShiftOf(s).value);
+ }
+};
+
+// Pointer-sized integer to be embedded as an immediate in an instruction.
+struct ImmWord
+{
+ uintptr_t value;
+
+ explicit ImmWord(uintptr_t value) : value(value)
+ { }
+};
+
+// Used for 64-bit immediates which do not require relocation.
+struct Imm64
+{
+ uint64_t value;
+
+ explicit Imm64(int64_t value) : value(value)
+ { }
+
+ Imm32 low() const {
+ return Imm32(int32_t(value));
+ }
+
+ Imm32 hi() const {
+ return Imm32(int32_t(value >> 32));
+ }
+
+ inline Imm32 firstHalf() const;
+ inline Imm32 secondHalf() const;
+};
+
+#ifdef DEBUG
+static inline bool
+IsCompilingWasm()
+{
+ // wasm compilation pushes a JitContext with a null JSCompartment.
+ return GetJitContext()->compartment == nullptr;
+}
+#endif
+
+// Pointer to be embedded as an immediate in an instruction.
+struct ImmPtr
+{
+ void* value;
+
+ explicit ImmPtr(const void* value) : value(const_cast<void*>(value))
+ {
+ // To make code serialization-safe, wasm compilation should only
+ // compile pointer immediates using a SymbolicAddress.
+ MOZ_ASSERT(!IsCompilingWasm());
+ }
+
+ template <class R>
+ explicit ImmPtr(R (*pf)())
+ : value(JS_FUNC_TO_DATA_PTR(void*, pf))
+ {
+ MOZ_ASSERT(!IsCompilingWasm());
+ }
+
+ template <class R, class A1>
+ explicit ImmPtr(R (*pf)(A1))
+ : value(JS_FUNC_TO_DATA_PTR(void*, pf))
+ {
+ MOZ_ASSERT(!IsCompilingWasm());
+ }
+
+ template <class R, class A1, class A2>
+ explicit ImmPtr(R (*pf)(A1, A2))
+ : value(JS_FUNC_TO_DATA_PTR(void*, pf))
+ {
+ MOZ_ASSERT(!IsCompilingWasm());
+ }
+
+ template <class R, class A1, class A2, class A3>
+ explicit ImmPtr(R (*pf)(A1, A2, A3))
+ : value(JS_FUNC_TO_DATA_PTR(void*, pf))
+ {
+ MOZ_ASSERT(!IsCompilingWasm());
+ }
+
+ template <class R, class A1, class A2, class A3, class A4>
+ explicit ImmPtr(R (*pf)(A1, A2, A3, A4))
+ : value(JS_FUNC_TO_DATA_PTR(void*, pf))
+ {
+ MOZ_ASSERT(!IsCompilingWasm());
+ }
+
+};
+
+// The same as ImmPtr except that the intention is to patch this
+// instruction. The initial value of the immediate is 'addr' and this value is
+// either clobbered or used in the patching process.
+struct PatchedImmPtr {
+ void* value;
+
+ explicit PatchedImmPtr()
+ : value(nullptr)
+ { }
+ explicit PatchedImmPtr(const void* value)
+ : value(const_cast<void*>(value))
+ { }
+};
+
+class AssemblerShared;
+class ImmGCPtr;
+
+// Used for immediates which require relocation.
+class ImmGCPtr
+{
+ public:
+ const gc::Cell* value;
+
+ explicit ImmGCPtr(const gc::Cell* ptr) : value(ptr)
+ {
+ // Nursery pointers can't be used if the main thread might be currently
+ // performing a minor GC.
+ MOZ_ASSERT_IF(ptr && !ptr->isTenured(),
+ !CurrentThreadIsIonCompilingSafeForMinorGC());
+
+ // wasm shouldn't be creating GC things
+ MOZ_ASSERT(!IsCompilingWasm());
+ }
+
+ private:
+ ImmGCPtr() : value(0) {}
+};
+
+// Pointer to be embedded as an immediate that is loaded/stored from by an
+// instruction.
+struct AbsoluteAddress
+{
+ void* addr;
+
+ explicit AbsoluteAddress(const void* addr)
+ : addr(const_cast<void*>(addr))
+ {
+ MOZ_ASSERT(!IsCompilingWasm());
+ }
+
+ AbsoluteAddress offset(ptrdiff_t delta) {
+ return AbsoluteAddress(((uint8_t*) addr) + delta);
+ }
+};
+
+// The same as AbsoluteAddress except that the intention is to patch this
+// instruction. The initial value of the immediate is 'addr' and this value is
+// either clobbered or used in the patching process.
+struct PatchedAbsoluteAddress
+{
+ void* addr;
+
+ explicit PatchedAbsoluteAddress()
+ : addr(nullptr)
+ { }
+ explicit PatchedAbsoluteAddress(const void* addr)
+ : addr(const_cast<void*>(addr))
+ { }
+ explicit PatchedAbsoluteAddress(uintptr_t addr)
+ : addr(reinterpret_cast<void*>(addr))
+ { }
+};
+
+// Specifies an address computed in the form of a register base and a constant,
+// 32-bit offset.
+struct Address
+{
+ Register base;
+ int32_t offset;
+
+ Address(Register base, int32_t offset) : base(base), offset(offset)
+ { }
+
+ Address() { mozilla::PodZero(this); }
+};
+
+// Specifies an address computed in the form of a register base, a register
+// index with a scale, and a constant, 32-bit offset.
+struct BaseIndex
+{
+ Register base;
+ Register index;
+ Scale scale;
+ int32_t offset;
+
+ BaseIndex(Register base, Register index, Scale scale, int32_t offset = 0)
+ : base(base), index(index), scale(scale), offset(offset)
+ { }
+
+ BaseIndex() { mozilla::PodZero(this); }
+};
+
+// A BaseIndex used to access Values. Note that |offset| is *not* scaled by
+// sizeof(Value). Use this *only* if you're indexing into a series of Values
+// that aren't object elements or object slots (for example, values on the
+// stack, values in an arguments object, &c.). If you're indexing into an
+// object's elements or slots, don't use this directly! Use
+// BaseObject{Element,Slot}Index instead.
+struct BaseValueIndex : BaseIndex
+{
+ BaseValueIndex(Register base, Register index, int32_t offset = 0)
+ : BaseIndex(base, index, ValueScale, offset)
+ { }
+};
+
+// Specifies the address of an indexed Value within object elements from a
+// base. The index must not already be scaled by sizeof(Value)!
+struct BaseObjectElementIndex : BaseValueIndex
+{
+ BaseObjectElementIndex(Register base, Register index, int32_t offset = 0)
+ : BaseValueIndex(base, index, offset)
+ {
+ NativeObject::elementsSizeMustNotOverflow();
+ }
+};
+
+// Like BaseObjectElementIndex, except for object slots.
+struct BaseObjectSlotIndex : BaseValueIndex
+{
+ BaseObjectSlotIndex(Register base, Register index)
+ : BaseValueIndex(base, index)
+ {
+ NativeObject::slotsSizeMustNotOverflow();
+ }
+};
+
+class Relocation {
+ public:
+ enum Kind {
+ // The target is immovable, so patching is only needed if the source
+ // buffer is relocated and the reference is relative.
+ HARDCODED,
+
+ // The target is the start of a JitCode buffer, which must be traced
+ // during garbage collection. Relocations and patching may be needed.
+ JITCODE
+ };
+};
+
+class RepatchLabel
+{
+ static const int32_t INVALID_OFFSET = 0xC0000000;
+ int32_t offset_ : 31;
+ uint32_t bound_ : 1;
+ public:
+
+ RepatchLabel() : offset_(INVALID_OFFSET), bound_(0) {}
+
+ void use(uint32_t newOffset) {
+ MOZ_ASSERT(offset_ == INVALID_OFFSET);
+ MOZ_ASSERT(newOffset != (uint32_t)INVALID_OFFSET);
+ offset_ = newOffset;
+ }
+ bool bound() const {
+ return bound_;
+ }
+ void bind(int32_t dest) {
+ MOZ_ASSERT(!bound_);
+ MOZ_ASSERT(dest != INVALID_OFFSET);
+ offset_ = dest;
+ bound_ = true;
+ }
+ int32_t target() {
+ MOZ_ASSERT(bound());
+ int32_t ret = offset_;
+ offset_ = INVALID_OFFSET;
+ return ret;
+ }
+ int32_t offset() {
+ MOZ_ASSERT(!bound());
+ return offset_;
+ }
+ bool used() const {
+ return !bound() && offset_ != (INVALID_OFFSET);
+ }
+
+};
+// An absolute label is like a Label, except it represents an absolute
+// reference rather than a relative one. Thus, it cannot be patched until after
+// linking.
+struct AbsoluteLabel : public LabelBase
+{
+ public:
+ AbsoluteLabel()
+ { }
+ AbsoluteLabel(const AbsoluteLabel& label) : LabelBase(label)
+ { }
+ int32_t prev() const {
+ MOZ_ASSERT(!bound());
+ if (!used())
+ return INVALID_OFFSET;
+ return offset();
+ }
+ void setPrev(int32_t offset) {
+ use(offset);
+ }
+ void bind() {
+ bound_ = true;
+
+ // These labels cannot be used after being bound.
+ offset_ = -1;
+ }
+};
+
+class CodeOffset
+{
+ size_t offset_;
+
+ static const size_t NOT_BOUND = size_t(-1);
+
+ public:
+ explicit CodeOffset(size_t offset) : offset_(offset) {}
+ CodeOffset() : offset_(NOT_BOUND) {}
+
+ size_t offset() const {
+ MOZ_ASSERT(bound());
+ return offset_;
+ }
+
+ void bind(size_t offset) {
+ MOZ_ASSERT(!bound());
+ offset_ = offset;
+ MOZ_ASSERT(bound());
+ }
+ bool bound() const {
+ return offset_ != NOT_BOUND;
+ }
+
+ void offsetBy(size_t delta) {
+ MOZ_ASSERT(bound());
+ MOZ_ASSERT(offset_ + delta >= offset_, "no overflow");
+ offset_ += delta;
+ }
+};
+
+// A code label contains an absolute reference to a point in the code. Thus, it
+// cannot be patched until after linking.
+// When the source label is resolved into a memory address, this address is
+// patched into the destination address.
+class CodeLabel
+{
+ // The destination position, where the absolute reference should get
+ // patched into.
+ CodeOffset patchAt_;
+
+ // The source label (relative) in the code to where the destination should
+ // get patched to.
+ CodeOffset target_;
+
+ public:
+ CodeLabel()
+ { }
+ explicit CodeLabel(const CodeOffset& patchAt)
+ : patchAt_(patchAt)
+ { }
+ CodeLabel(const CodeOffset& patchAt, const CodeOffset& target)
+ : patchAt_(patchAt),
+ target_(target)
+ { }
+ CodeOffset* patchAt() {
+ return &patchAt_;
+ }
+ CodeOffset* target() {
+ return &target_;
+ }
+ void offsetBy(size_t delta) {
+ patchAt_.offsetBy(delta);
+ target_.offsetBy(delta);
+ }
+};
+
+// Location of a jump or label in a generated JitCode block, relative to the
+// start of the block.
+
+class CodeOffsetJump
+{
+ size_t offset_;
+
+#ifdef JS_SMALL_BRANCH
+ size_t jumpTableIndex_;
+#endif
+
+ public:
+
+#ifdef JS_SMALL_BRANCH
+ CodeOffsetJump(size_t offset, size_t jumpTableIndex)
+ : offset_(offset), jumpTableIndex_(jumpTableIndex)
+ {}
+ size_t jumpTableIndex() const {
+ return jumpTableIndex_;
+ }
+#else
+ explicit CodeOffsetJump(size_t offset) : offset_(offset) {}
+#endif
+
+ CodeOffsetJump() {
+ mozilla::PodZero(this);
+ }
+
+ size_t offset() const {
+ return offset_;
+ }
+ void fixup(MacroAssembler* masm);
+};
+
+// Absolute location of a jump or a label in some generated JitCode block.
+// Can also encode a CodeOffset{Jump,Label}, such that the offset is initially
+// set and the absolute location later filled in after the final JitCode is
+// allocated.
+
+class CodeLocationJump
+{
+ uint8_t* raw_;
+#ifdef DEBUG
+ enum State { Uninitialized, Absolute, Relative };
+ State state_;
+ void setUninitialized() {
+ state_ = Uninitialized;
+ }
+ void setAbsolute() {
+ state_ = Absolute;
+ }
+ void setRelative() {
+ state_ = Relative;
+ }
+#else
+ void setUninitialized() const {
+ }
+ void setAbsolute() const {
+ }
+ void setRelative() const {
+ }
+#endif
+
+#ifdef JS_SMALL_BRANCH
+ uint8_t* jumpTableEntry_;
+#endif
+
+ public:
+ CodeLocationJump() {
+ raw_ = nullptr;
+ setUninitialized();
+#ifdef JS_SMALL_BRANCH
+ jumpTableEntry_ = (uint8_t*) uintptr_t(0xdeadab1e);
+#endif
+ }
+ CodeLocationJump(JitCode* code, CodeOffsetJump base) {
+ *this = base;
+ repoint(code);
+ }
+
+ void operator = (CodeOffsetJump base) {
+ raw_ = (uint8_t*) base.offset();
+ setRelative();
+#ifdef JS_SMALL_BRANCH
+ jumpTableEntry_ = (uint8_t*) base.jumpTableIndex();
+#endif
+ }
+
+ void repoint(JitCode* code, MacroAssembler* masm = nullptr);
+
+ uint8_t* raw() const {
+ MOZ_ASSERT(state_ == Absolute);
+ return raw_;
+ }
+ uint8_t* offset() const {
+ MOZ_ASSERT(state_ == Relative);
+ return raw_;
+ }
+
+#ifdef JS_SMALL_BRANCH
+ uint8_t* jumpTableEntry() const {
+ MOZ_ASSERT(state_ == Absolute);
+ return jumpTableEntry_;
+ }
+#endif
+};
+
+class CodeLocationLabel
+{
+ uint8_t* raw_;
+#ifdef DEBUG
+ enum State { Uninitialized, Absolute, Relative };
+ State state_;
+ void setUninitialized() {
+ state_ = Uninitialized;
+ }
+ void setAbsolute() {
+ state_ = Absolute;
+ }
+ void setRelative() {
+ state_ = Relative;
+ }
+#else
+ void setUninitialized() const {
+ }
+ void setAbsolute() const {
+ }
+ void setRelative() const {
+ }
+#endif
+
+ public:
+ CodeLocationLabel() {
+ raw_ = nullptr;
+ setUninitialized();
+ }
+ CodeLocationLabel(JitCode* code, CodeOffset base) {
+ *this = base;
+ repoint(code);
+ }
+ explicit CodeLocationLabel(JitCode* code) {
+ raw_ = code->raw();
+ setAbsolute();
+ }
+ explicit CodeLocationLabel(uint8_t* raw) {
+ raw_ = raw;
+ setAbsolute();
+ }
+
+ void operator = (CodeOffset base) {
+ raw_ = (uint8_t*)base.offset();
+ setRelative();
+ }
+ ptrdiff_t operator - (const CodeLocationLabel& other) {
+ return raw_ - other.raw_;
+ }
+
+ void repoint(JitCode* code, MacroAssembler* masm = nullptr);
+
+#ifdef DEBUG
+ bool isSet() const {
+ return state_ != Uninitialized;
+ }
+#endif
+
+ uint8_t* raw() const {
+ MOZ_ASSERT(state_ == Absolute);
+ return raw_;
+ }
+ uint8_t* offset() const {
+ MOZ_ASSERT(state_ == Relative);
+ return raw_;
+ }
+};
+
+} // namespace jit
+
+namespace wasm {
+
+// As an invariant across architectures, within wasm code:
+// $sp % WasmStackAlignment = (sizeof(wasm::Frame) + masm.framePushed) % WasmStackAlignment
+// Thus, wasm::Frame represents the bytes pushed after the call (which occurred
+// with a WasmStackAlignment-aligned StackPointer) that are not included in
+// masm.framePushed.
+
+struct Frame
+{
+ // The caller's saved frame pointer. In non-profiling mode, internal
+ // wasm-to-wasm calls don't update fp and thus don't save the caller's
+ // frame pointer; the space is reserved, however, so that profiling mode can
+ // reuse the same function body without recompiling.
+ uint8_t* callerFP;
+
+ // The return address pushed by the call (in the case of ARM/MIPS the return
+ // address is pushed by the first instruction of the prologue).
+ void* returnAddress;
+};
+
+static_assert(sizeof(Frame) == 2 * sizeof(void*), "?!");
+static const uint32_t FrameBytesAfterReturnAddress = sizeof(void*);
+
+// Represents an instruction to be patched and the intended pointee. These
+// links are accumulated in the MacroAssembler, but patching is done outside
+// the MacroAssembler (in Module::staticallyLink).
+
+struct SymbolicAccess
+{
+ SymbolicAccess(jit::CodeOffset patchAt, SymbolicAddress target)
+ : patchAt(patchAt), target(target) {}
+
+ jit::CodeOffset patchAt;
+ SymbolicAddress target;
+};
+
+typedef Vector<SymbolicAccess, 0, SystemAllocPolicy> SymbolicAccessVector;
+
+// Describes a single wasm or asm.js memory access for the purpose of generating
+// code and metadata.
+
+class MemoryAccessDesc
+{
+ uint32_t offset_;
+ uint32_t align_;
+ Scalar::Type type_;
+ unsigned numSimdElems_;
+ jit::MemoryBarrierBits barrierBefore_;
+ jit::MemoryBarrierBits barrierAfter_;
+ mozilla::Maybe<wasm::TrapOffset> trapOffset_;
+
+ public:
+ explicit MemoryAccessDesc(Scalar::Type type, uint32_t align, uint32_t offset,
+ mozilla::Maybe<TrapOffset> trapOffset,
+ unsigned numSimdElems = 0,
+ jit::MemoryBarrierBits barrierBefore = jit::MembarNobits,
+ jit::MemoryBarrierBits barrierAfter = jit::MembarNobits)
+ : offset_(offset),
+ align_(align),
+ type_(type),
+ numSimdElems_(numSimdElems),
+ barrierBefore_(barrierBefore),
+ barrierAfter_(barrierAfter),
+ trapOffset_(trapOffset)
+ {
+ MOZ_ASSERT(Scalar::isSimdType(type) == (numSimdElems > 0));
+ MOZ_ASSERT(numSimdElems <= jit::ScalarTypeToLength(type));
+ MOZ_ASSERT(mozilla::IsPowerOfTwo(align));
+ MOZ_ASSERT_IF(isSimd(), hasTrap());
+ MOZ_ASSERT_IF(isAtomic(), hasTrap());
+ }
+
+ uint32_t offset() const { return offset_; }
+ uint32_t align() const { return align_; }
+ Scalar::Type type() const { return type_; }
+ unsigned byteSize() const {
+ return Scalar::isSimdType(type())
+ ? Scalar::scalarByteSize(type()) * numSimdElems()
+ : Scalar::byteSize(type());
+ }
+ unsigned numSimdElems() const { MOZ_ASSERT(isSimd()); return numSimdElems_; }
+ jit::MemoryBarrierBits barrierBefore() const { return barrierBefore_; }
+ jit::MemoryBarrierBits barrierAfter() const { return barrierAfter_; }
+ bool hasTrap() const { return !!trapOffset_; }
+ TrapOffset trapOffset() const { return *trapOffset_; }
+ bool isAtomic() const { return (barrierBefore_ | barrierAfter_) != jit::MembarNobits; }
+ bool isSimd() const { return Scalar::isSimdType(type_); }
+ bool isUnaligned() const { return align() && align() < byteSize(); }
+ bool isPlainAsmJS() const { return !hasTrap(); }
+
+ void clearOffset() { offset_ = 0; }
+};
+
+// Summarizes a global access for a mutable (in asm.js) or immutable value (in
+// asm.js or the wasm MVP) that needs to get patched later.
+
+struct GlobalAccess
+{
+ GlobalAccess(jit::CodeOffset patchAt, unsigned globalDataOffset)
+ : patchAt(patchAt), globalDataOffset(globalDataOffset)
+ {}
+
+ jit::CodeOffset patchAt;
+ unsigned globalDataOffset;
+};
+
+typedef Vector<GlobalAccess, 0, SystemAllocPolicy> GlobalAccessVector;
+
+// The TrapDesc struct describes a wasm trap that is about to be emitted. This
+// includes the logical wasm bytecode offset to report, the kind of instruction
+// causing the trap, and the stack depth right before control is transferred to
+// the trap out-of-line path.
+
+struct TrapDesc : TrapOffset
+{
+ enum Kind { Jump, MemoryAccess };
+ Kind kind;
+ Trap trap;
+ uint32_t framePushed;
+
+ TrapDesc(TrapOffset offset, Trap trap, uint32_t framePushed, Kind kind = Jump)
+ : TrapOffset(offset), kind(kind), trap(trap), framePushed(framePushed)
+ {}
+};
+
+// A TrapSite captures all relevant information at the point of emitting the
+// in-line trapping instruction for the purpose of generating the out-of-line
+// trap code (at the end of the function).
+
+struct TrapSite : TrapDesc
+{
+ uint32_t codeOffset;
+
+ TrapSite(TrapDesc trap, uint32_t codeOffset)
+ : TrapDesc(trap), codeOffset(codeOffset)
+ {}
+};
+
+typedef Vector<TrapSite, 0, SystemAllocPolicy> TrapSiteVector;
+
+// A TrapFarJump records the offset of a jump that needs to be patched to a trap
+// exit at the end of the module when trap exits are emitted.
+
+struct TrapFarJump
+{
+ Trap trap;
+ jit::CodeOffset jump;
+
+ TrapFarJump(Trap trap, jit::CodeOffset jump)
+ : trap(trap), jump(jump)
+ {}
+
+ void offsetBy(size_t delta) {
+ jump.offsetBy(delta);
+ }
+};
+
+typedef Vector<TrapFarJump, 0, SystemAllocPolicy> TrapFarJumpVector;
+
+} // namespace wasm
+
+namespace jit {
+
+// The base class of all Assemblers for all archs.
+class AssemblerShared
+{
+ wasm::CallSiteAndTargetVector callSites_;
+ wasm::TrapSiteVector trapSites_;
+ wasm::TrapFarJumpVector trapFarJumps_;
+ wasm::MemoryAccessVector memoryAccesses_;
+ wasm::MemoryPatchVector memoryPatches_;
+ wasm::BoundsCheckVector boundsChecks_;
+ wasm::GlobalAccessVector globalAccesses_;
+ wasm::SymbolicAccessVector symbolicAccesses_;
+
+ protected:
+ Vector<CodeLabel, 0, SystemAllocPolicy> codeLabels_;
+
+ bool enoughMemory_;
+ bool embedsNurseryPointers_;
+
+ public:
+ AssemblerShared()
+ : enoughMemory_(true),
+ embedsNurseryPointers_(false)
+ {}
+
+ void propagateOOM(bool success) {
+ enoughMemory_ &= success;
+ }
+
+ void setOOM() {
+ enoughMemory_ = false;
+ }
+
+ bool oom() const {
+ return !enoughMemory_;
+ }
+
+ bool embedsNurseryPointers() const {
+ return embedsNurseryPointers_;
+ }
+
+ template <typename... Args>
+ void append(const wasm::CallSiteDesc& desc, CodeOffset retAddr, size_t framePushed,
+ Args&&... args)
+ {
+ // framePushed does not include sizeof(wasm:Frame), so add it in explicitly when
+ // setting the CallSite::stackDepth.
+ wasm::CallSite cs(desc, retAddr.offset(), framePushed + sizeof(wasm::Frame));
+ enoughMemory_ &= callSites_.emplaceBack(cs, mozilla::Forward<Args>(args)...);
+ }
+ wasm::CallSiteAndTargetVector& callSites() { return callSites_; }
+
+ void append(wasm::TrapSite trapSite) {
+ enoughMemory_ &= trapSites_.append(trapSite);
+ }
+ const wasm::TrapSiteVector& trapSites() const { return trapSites_; }
+ void clearTrapSites() { trapSites_.clear(); }
+
+ void append(wasm::TrapFarJump jmp) {
+ enoughMemory_ &= trapFarJumps_.append(jmp);
+ }
+ const wasm::TrapFarJumpVector& trapFarJumps() const { return trapFarJumps_; }
+
+ void append(wasm::MemoryAccess access) { enoughMemory_ &= memoryAccesses_.append(access); }
+ wasm::MemoryAccessVector&& extractMemoryAccesses() { return Move(memoryAccesses_); }
+
+ void append(const wasm::MemoryAccessDesc& access, size_t codeOffset, size_t framePushed) {
+ if (access.hasTrap()) {
+ // If a memory access is trapping (wasm, SIMD.js, Atomics), create a
+ // TrapSite now which will generate a trap out-of-line path at the end
+ // of the function which will *then* append a MemoryAccess.
+ wasm::TrapDesc trap(access.trapOffset(), wasm::Trap::OutOfBounds, framePushed,
+ wasm::TrapSite::MemoryAccess);
+ append(wasm::TrapSite(trap, codeOffset));
+ } else {
+ // Otherwise, this is a plain asm.js access. On WASM_HUGE_MEMORY
+ // platforms, asm.js uses signal handlers to remove bounds checks
+ // and thus requires a MemoryAccess.
+ MOZ_ASSERT(access.isPlainAsmJS());
+#ifdef WASM_HUGE_MEMORY
+ append(wasm::MemoryAccess(codeOffset));
+#endif
+ }
+ }
+
+ void append(wasm::MemoryPatch patch) { enoughMemory_ &= memoryPatches_.append(patch); }
+ wasm::MemoryPatchVector&& extractMemoryPatches() { return Move(memoryPatches_); }
+
+ void append(wasm::BoundsCheck check) { enoughMemory_ &= boundsChecks_.append(check); }
+ wasm::BoundsCheckVector&& extractBoundsChecks() { return Move(boundsChecks_); }
+
+ void append(wasm::GlobalAccess access) { enoughMemory_ &= globalAccesses_.append(access); }
+ const wasm::GlobalAccessVector& globalAccesses() const { return globalAccesses_; }
+
+ void append(wasm::SymbolicAccess access) { enoughMemory_ &= symbolicAccesses_.append(access); }
+ size_t numSymbolicAccesses() const { return symbolicAccesses_.length(); }
+ wasm::SymbolicAccess symbolicAccess(size_t i) const { return symbolicAccesses_[i]; }
+
+ static bool canUseInSingleByteInstruction(Register reg) { return true; }
+
+ void addCodeLabel(CodeLabel label) {
+ propagateOOM(codeLabels_.append(label));
+ }
+ size_t numCodeLabels() const {
+ return codeLabels_.length();
+ }
+ CodeLabel codeLabel(size_t i) {
+ return codeLabels_[i];
+ }
+
+ // Merge this assembler with the other one, invalidating it, by shifting all
+ // offsets by a delta.
+ bool asmMergeWith(size_t delta, const AssemblerShared& other) {
+ size_t i = callSites_.length();
+ enoughMemory_ &= callSites_.appendAll(other.callSites_);
+ for (; i < callSites_.length(); i++)
+ callSites_[i].offsetReturnAddressBy(delta);
+
+ MOZ_ASSERT(other.trapSites_.empty(), "should have been cleared by wasmEmitTrapOutOfLineCode");
+
+ i = trapFarJumps_.length();
+ enoughMemory_ &= trapFarJumps_.appendAll(other.trapFarJumps_);
+ for (; i < trapFarJumps_.length(); i++)
+ trapFarJumps_[i].offsetBy(delta);
+
+ i = memoryAccesses_.length();
+ enoughMemory_ &= memoryAccesses_.appendAll(other.memoryAccesses_);
+ for (; i < memoryAccesses_.length(); i++)
+ memoryAccesses_[i].offsetBy(delta);
+
+ i = memoryPatches_.length();
+ enoughMemory_ &= memoryPatches_.appendAll(other.memoryPatches_);
+ for (; i < memoryPatches_.length(); i++)
+ memoryPatches_[i].offsetBy(delta);
+
+ i = boundsChecks_.length();
+ enoughMemory_ &= boundsChecks_.appendAll(other.boundsChecks_);
+ for (; i < boundsChecks_.length(); i++)
+ boundsChecks_[i].offsetBy(delta);
+
+ i = globalAccesses_.length();
+ enoughMemory_ &= globalAccesses_.appendAll(other.globalAccesses_);
+ for (; i < globalAccesses_.length(); i++)
+ globalAccesses_[i].patchAt.offsetBy(delta);
+
+ i = symbolicAccesses_.length();
+ enoughMemory_ &= symbolicAccesses_.appendAll(other.symbolicAccesses_);
+ for (; i < symbolicAccesses_.length(); i++)
+ symbolicAccesses_[i].patchAt.offsetBy(delta);
+
+ i = codeLabels_.length();
+ enoughMemory_ &= codeLabels_.appendAll(other.codeLabels_);
+ for (; i < codeLabels_.length(); i++)
+ codeLabels_[i].offsetBy(delta);
+
+ return !oom();
+ }
+};
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_shared_Assembler_shared_h */