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diff --git a/js/src/wasm/WasmBCClass.h b/js/src/wasm/WasmBCClass.h new file mode 100644 index 0000000000..c216d0ffd5 --- /dev/null +++ b/js/src/wasm/WasmBCClass.h @@ -0,0 +1,1806 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * + * Copyright 2016 Mozilla Foundation + * + * 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. + */ + +// This is an INTERNAL header for Wasm baseline compiler: the compiler object +// and its supporting types. + +#ifndef wasm_wasm_baseline_object_h +#define wasm_wasm_baseline_object_h + +#include "wasm/WasmBCDefs.h" +#include "wasm/WasmBCFrame.h" +#include "wasm/WasmBCRegDefs.h" +#include "wasm/WasmBCStk.h" +#include "wasm/WasmConstants.h" + +namespace js { +namespace wasm { + +// Container for a piece of out-of-line code, the slow path that supports an +// operation. +class OutOfLineCode; + +// Part of the inter-bytecode state for the boolean-evaluation-for-control +// optimization. +struct BranchState; + +// Representation of wasm local variables. +using Local = BaseStackFrame::Local; + +// Bitset used for simple bounds check elimination. Capping this at 64 locals +// makes sense; even 32 locals would probably be OK in practice. +// +// For more information about BCE, see the block comment in WasmBCMemory.cpp. +using BCESet = uint64_t; + +// Information stored in the control node for generating exception handling +// landing pads. +struct CatchInfo { + uint32_t tagIndex; // Index for the associated exception. + NonAssertingLabel label; // The entry label for the handler. + + explicit CatchInfo(uint32_t tagIndex_) : tagIndex(tagIndex_) {} +}; + +using CatchInfoVector = Vector<CatchInfo, 1, SystemAllocPolicy>; + +// Control node, representing labels and stack heights at join points. +struct Control { + NonAssertingLabel label; // The "exit" label + NonAssertingLabel otherLabel; // Used for the "else" branch of if-then-else + // and to allow delegate to jump to catches. + StackHeight stackHeight; // From BaseStackFrame + uint32_t stackSize; // Value stack height + BCESet bceSafeOnEntry; // Bounds check info flowing into the item + BCESet bceSafeOnExit; // Bounds check info flowing out of the item + bool deadOnArrival; // deadCode_ was set on entry to the region + bool deadThenBranch; // deadCode_ was set on exit from "then" + size_t tryNoteIndex; // For tracking try branch code ranges. + CatchInfoVector catchInfos; // Used for try-catch handlers. + + Control() + : stackHeight(StackHeight::Invalid()), + stackSize(UINT32_MAX), + bceSafeOnEntry(0), + bceSafeOnExit(~BCESet(0)), + deadOnArrival(false), + deadThenBranch(false), + tryNoteIndex(0) {} + + Control(Control&&) = default; + Control(const Control&) = delete; +}; + +// A vector of Nothing values, used for reading opcodes. +class BaseNothingVector { + Nothing unused_; + + public: + bool reserve(size_t size) { return true; } + bool resize(size_t length) { return true; } + Nothing& operator[](size_t) { return unused_; } + Nothing& back() { return unused_; } + size_t length() const { return 0; } + bool append(Nothing& nothing) { return true; } + void infallibleAppend(Nothing& nothing) {} +}; + +// The baseline compiler tracks values on a stack of its own -- it needs to scan +// that stack for spilling -- and thus has no need for the values maintained by +// the iterator. +struct BaseCompilePolicy { + using Value = Nothing; + using ValueVector = BaseNothingVector; + + // The baseline compiler uses the iterator's control stack, attaching + // its own control information. + using ControlItem = Control; +}; + +using BaseOpIter = OpIter<BaseCompilePolicy>; + +// Latent operation for boolean-evaluation-for-control optimization. +enum class LatentOp { None, Compare, Eqz }; + +// Encapsulate the checking needed for a memory access. +struct AccessCheck { + AccessCheck() + : omitBoundsCheck(false), + omitAlignmentCheck(false), + onlyPointerAlignment(false) {} + + // If `omitAlignmentCheck` is true then we need check neither the + // pointer nor the offset. Otherwise, if `onlyPointerAlignment` is true + // then we need check only the pointer. Otherwise, check the sum of + // pointer and offset. + + bool omitBoundsCheck; + bool omitAlignmentCheck; + bool onlyPointerAlignment; +}; + +// Encapsulate all the information about a function call. +struct FunctionCall { + FunctionCall() + : restoreRegisterStateAndRealm(false), + usesSystemAbi(false), +#ifdef JS_CODEGEN_ARM + hardFP(true), +#endif + frameAlignAdjustment(0), + stackArgAreaSize(0) { + } + + WasmABIArgGenerator abi; + bool restoreRegisterStateAndRealm; + bool usesSystemAbi; +#ifdef JS_CODEGEN_ARM + bool hardFP; +#endif + size_t frameAlignAdjustment; + size_t stackArgAreaSize; +}; + +enum class PreBarrierKind { + // No pre-write barrier is required because the previous value is undefined. + None, + // Perform a pre-write barrier to mark the previous value if an incremental + // GC is underway. + Normal, +}; + +enum class PostBarrierKind { + // Remove an existing store buffer entry if the new value does not require + // one. This is required to preserve invariants with HeapPtr when used for + // movable storage. + Precise, + // Add a store buffer entry if the new value requires it, but do not attempt + // to remove a pre-existing entry. + Imprecise, +}; + +struct BranchIfRefSubtypeRegisters { + RegPtr superSTV; + RegI32 scratch1; + RegI32 scratch2; +}; + +////////////////////////////////////////////////////////////////////////////// +// +// Wasm baseline compiler proper. +// +// This is a struct and not a class because there is no real benefit to hiding +// anything, and because many static functions that are wrappers for masm +// methods need to reach into it and would otherwise have to be declared as +// friends. +// +// (Members generally have a '_' suffix but some don't because they are +// referenced everywhere and it would be tedious to spell that out.) + +struct BaseCompiler final { + /////////////////////////////////////////////////////////////////////////// + // + // Private types + + using LabelVector = Vector<NonAssertingLabel, 8, SystemAllocPolicy>; + + /////////////////////////////////////////////////////////////////////////// + // + // Read-only and write-once members. + + // Static compilation environment. + const ModuleEnvironment& moduleEnv_; + const CompilerEnvironment& compilerEnv_; + const FuncCompileInput& func_; + const ValTypeVector& locals_; + + // Information about the locations of locals, this is set up during + // initialization and read-only after that. + BaseStackFrame::LocalVector localInfo_; + + // On specific platforms we sometimes need to use specific registers. + const SpecificRegs specific_; + + // SigD and SigF are single-entry parameter lists for f64 and f32, these are + // created during initialization. + ValTypeVector SigD_; + ValTypeVector SigF_; + + // Where to go to to return, bound as compilation ends. + NonAssertingLabel returnLabel_; + + // Prologue and epilogue offsets, initialized during prologue and epilogue + // generation and only used by the caller. + FuncOffsets offsets_; + + // We call this address from the breakable point when the breakpoint handler + // is not null. + NonAssertingLabel debugTrapStub_; + uint32_t previousBreakablePoint_; + + // BaselineCompileFunctions() "lends" us the StkVector to use in this + // BaseCompiler object, and that is installed in |stk_| in our constructor. + // This is so as to avoid having to malloc/free the vector's contents at + // each creation/destruction of a BaseCompiler object. It does however mean + // that we need to hold on to a reference to BaselineCompileFunctions()'s + // vector, so we can swap (give) its contents back when this BaseCompiler + // object is destroyed. This significantly reduces the heap turnover of the + // baseline compiler. See bug 1532592. + StkVector& stkSource_; + + /////////////////////////////////////////////////////////////////////////// + // + // Output-only data structures. + + // Bump allocator for temporary memory, used for the value stack and + // out-of-line code blobs. Bump-allocated memory is not freed until the end + // of the compilation. + TempAllocator::Fallible alloc_; + + // Machine code emitter. + MacroAssembler& masm; + + /////////////////////////////////////////////////////////////////////////// + // + // Compilation state. + + // Decoder for this function, used for misc error reporting. + Decoder& decoder_; + + // Opcode reader. + BaseOpIter iter_; + + // Register allocator. + BaseRegAlloc ra; + + // Stack frame abstraction. + BaseStackFrame fr; + + // Latent out of line support code for some operations, code for these will be + // emitted at the end of compilation. + Vector<OutOfLineCode*, 8, SystemAllocPolicy> outOfLine_; + + // Stack map state. This keeps track of live pointer slots and allows precise + // stack maps to be generated at safe points. + StackMapGenerator stackMapGenerator_; + + // Wasm value stack. This maps values on the wasm stack to values in the + // running code and their locations. + // + // The value stack facilitates on-the-fly register allocation and the use of + // immediates in instructions. It tracks latent constants, latent references + // to locals, register contents, and values that have been flushed to the CPU + // stack. + // + // The stack can be flushed to the CPU stack using sync(). + // + // The stack is a StkVector rather than a StkVector& since constantly + // dereferencing a StkVector& has been shown to add 0.5% or more to the + // compiler's dynamic instruction count. + StkVector stk_; + + // Flag indicating that the compiler is currently in a dead code region. + bool deadCode_; + + /////////////////////////////////////////////////////////////////////////// + // + // State for bounds check elimination. + + // Locals that have been bounds checked and not updated since + BCESet bceSafe_; + + /////////////////////////////////////////////////////////////////////////// + // + // State for boolean-evaluation-for-control. + + // Latent operation for branch (seen next) + LatentOp latentOp_; + + // Operand type, if latentOp_ is true + ValType latentType_; + + // Comparison operator, if latentOp_ == Compare, int types + Assembler::Condition latentIntCmp_; + + // Comparison operator, if latentOp_ == Compare, float types + Assembler::DoubleCondition latentDoubleCmp_; + + /////////////////////////////////////////////////////////////////////////// + // + // Main compilation API. + // + // A client will create a compiler object, and then call init(), + // emitFunction(), and finish() in that order. + + BaseCompiler(const ModuleEnvironment& moduleEnv, + const CompilerEnvironment& compilerEnv, + const FuncCompileInput& func, const ValTypeVector& locals, + const RegisterOffsets& trapExitLayout, + size_t trapExitLayoutNumWords, Decoder& decoder, + StkVector& stkSource, TempAllocator* alloc, MacroAssembler* masm, + StackMaps* stackMaps); + ~BaseCompiler(); + + [[nodiscard]] bool init(); + [[nodiscard]] bool emitFunction(); + [[nodiscard]] FuncOffsets finish(); + + ////////////////////////////////////////////////////////////////////////////// + // + // Sundry accessor abstractions and convenience predicates. + // + // WasmBaselineObject-inl.h. + + inline const FuncType& funcType() const; + inline bool usesMemory() const; + inline bool usesSharedMemory(uint32_t memoryIndex) const; + inline bool isMem32(uint32_t memoryIndex) const; + inline bool isMem64(uint32_t memoryIndex) const; + inline bool hugeMemoryEnabled(uint32_t memoryIndex) const; + inline uint32_t instanceOffsetOfMemoryBase(uint32_t memoryIndex) const; + inline uint32_t instanceOffsetOfBoundsCheckLimit(uint32_t memoryIndex) const; + + // The casts are used by some of the ScratchRegister implementations. + operator MacroAssembler&() const { return masm; } + operator BaseRegAlloc&() { return ra; } + + ////////////////////////////////////////////////////////////////////////////// + // + // Locals. + // + // WasmBaselineObject-inl.h. + + // Assert that the local at the given index has the given type, and return a + // reference to the Local. + inline const Local& localFromSlot(uint32_t slot, MIRType type); + + ////////////////////////////////////////////////////////////////////////////// + // + // Out of line code management. + + [[nodiscard]] OutOfLineCode* addOutOfLineCode(OutOfLineCode* ool); + [[nodiscard]] bool generateOutOfLineCode(); + + ///////////////////////////////////////////////////////////////////////////// + // + // Layering in the compiler (briefly). + // + // At the lowest layers are abstractions for registers (managed by the + // BaseRegAlloc and the wrappers below) and the stack frame (managed by the + // BaseStackFrame). + // + // The registers and frame are in turn used by the value abstraction, which is + // implemented by the Stk type and backed by the value stack. Values may be + // stored in registers, in the frame, or may be latent constants, and the + // value stack handles storage mostly transparently in its push and pop + // routines. + // + // In turn, the pop routines bring values into registers so that we can + // compute on them, and the push routines move values to the stack (where they + // may still reside in registers until the registers are needed or the value + // must be in memory). + // + // Routines for managing parameters and results (for blocks or calls) may also + // manipulate the stack directly. + // + // At the top are the code generators: methods that use the poppers and + // pushers and other utilities to move values into place, and that emit code + // to compute on those values or change control flow. + + ///////////////////////////////////////////////////////////////////////////// + // + // Register management. These are simply strongly-typed wrappers that + // delegate to the register allocator. + + inline bool isAvailableI32(RegI32 r); + inline bool isAvailableI64(RegI64 r); + inline bool isAvailableRef(RegRef r); + inline bool isAvailablePtr(RegPtr r); + inline bool isAvailableF32(RegF32 r); + inline bool isAvailableF64(RegF64 r); +#ifdef ENABLE_WASM_SIMD + inline bool isAvailableV128(RegV128 r); +#endif + + // Allocate any register + [[nodiscard]] inline RegI32 needI32(); + [[nodiscard]] inline RegI64 needI64(); + [[nodiscard]] inline RegRef needRef(); + [[nodiscard]] inline RegPtr needPtr(); + [[nodiscard]] inline RegF32 needF32(); + [[nodiscard]] inline RegF64 needF64(); +#ifdef ENABLE_WASM_SIMD + [[nodiscard]] inline RegV128 needV128(); +#endif + + // Allocate a specific register + inline void needI32(RegI32 specific); + inline void needI64(RegI64 specific); + inline void needRef(RegRef specific); + inline void needPtr(RegPtr specific); + inline void needF32(RegF32 specific); + inline void needF64(RegF64 specific); +#ifdef ENABLE_WASM_SIMD + inline void needV128(RegV128 specific); +#endif + + template <typename RegType> + inline RegType need(); + + // Just a shorthand. + inline void need2xI32(RegI32 r0, RegI32 r1); + inline void need2xI64(RegI64 r0, RegI64 r1); + + // Get a register but do not sync the stack to free one up. This will crash + // if no register is available. + inline void needI32NoSync(RegI32 r); + +#if defined(JS_CODEGEN_ARM) + // Allocate a specific register pair (even-odd register numbers). + [[nodiscard]] inline RegI64 needI64Pair(); +#endif + + inline void freeAny(AnyReg r); + inline void freeI32(RegI32 r); + inline void freeI64(RegI64 r); + inline void freeRef(RegRef r); + inline void freePtr(RegPtr r); + inline void freeF32(RegF32 r); + inline void freeF64(RegF64 r); +#ifdef ENABLE_WASM_SIMD + inline void freeV128(RegV128 r); +#endif + + template <typename RegType> + inline void free(RegType r); + + // Free r if it is not invalid. + inline void maybeFree(RegI32 r); + inline void maybeFree(RegI64 r); + inline void maybeFree(RegF32 r); + inline void maybeFree(RegF64 r); + inline void maybeFree(RegRef r); + inline void maybeFree(RegPtr r); +#ifdef ENABLE_WASM_SIMD + inline void maybeFree(RegV128 r); +#endif + + // On 64-bit systems, `except` must equal r and this is a no-op. On 32-bit + // systems, `except` must equal the high or low part of a pair and the other + // part of the pair is freed. + inline void freeI64Except(RegI64 r, RegI32 except); + + // Return the 32-bit low part of the 64-bit register, do not free anything. + inline RegI32 fromI64(RegI64 r); + + // If r is valid, return fromI64(r), otherwise an invalid RegI32. + inline RegI32 maybeFromI64(RegI64 r); + +#ifdef JS_PUNBOX64 + // On 64-bit systems, reinterpret r as 64-bit. + inline RegI64 fromI32(RegI32 r); +#endif + + // Widen r to 64 bits; this may allocate another register to form a pair. + // Note this does not generate code for sign/zero extension. + inline RegI64 widenI32(RegI32 r); + + // Narrow r to 32 bits; this may free part of a pair. Note this does not + // generate code to canonicalize the value on 64-bit systems. + inline RegI32 narrowI64(RegI64 r); + inline RegI32 narrowRef(RegRef r); + + // Return the 32-bit low part of r. + inline RegI32 lowPart(RegI64 r); + + // On 64-bit systems, return an invalid register. On 32-bit systems, return + // the low part of a pair. + inline RegI32 maybeHighPart(RegI64 r); + + // On 64-bit systems, do nothing. On 32-bit systems, clear the high register. + inline void maybeClearHighPart(RegI64 r); + + ////////////////////////////////////////////////////////////////////////////// + // + // Values and value stack: Low-level methods for moving Stk values of specific + // kinds to registers. + + inline void loadConstI32(const Stk& src, RegI32 dest); + inline void loadMemI32(const Stk& src, RegI32 dest); + inline void loadLocalI32(const Stk& src, RegI32 dest); + inline void loadRegisterI32(const Stk& src, RegI32 dest); + inline void loadConstI64(const Stk& src, RegI64 dest); + inline void loadMemI64(const Stk& src, RegI64 dest); + inline void loadLocalI64(const Stk& src, RegI64 dest); + inline void loadRegisterI64(const Stk& src, RegI64 dest); + inline void loadConstRef(const Stk& src, RegRef dest); + inline void loadMemRef(const Stk& src, RegRef dest); + inline void loadLocalRef(const Stk& src, RegRef dest); + inline void loadRegisterRef(const Stk& src, RegRef dest); + inline void loadConstF64(const Stk& src, RegF64 dest); + inline void loadMemF64(const Stk& src, RegF64 dest); + inline void loadLocalF64(const Stk& src, RegF64 dest); + inline void loadRegisterF64(const Stk& src, RegF64 dest); + inline void loadConstF32(const Stk& src, RegF32 dest); + inline void loadMemF32(const Stk& src, RegF32 dest); + inline void loadLocalF32(const Stk& src, RegF32 dest); + inline void loadRegisterF32(const Stk& src, RegF32 dest); +#ifdef ENABLE_WASM_SIMD + inline void loadConstV128(const Stk& src, RegV128 dest); + inline void loadMemV128(const Stk& src, RegV128 dest); + inline void loadLocalV128(const Stk& src, RegV128 dest); + inline void loadRegisterV128(const Stk& src, RegV128 dest); +#endif + + ////////////////////////////////////////////////////////////////////////// + // + // Values and value stack: Mid-level routines for moving Stk values of any + // kind to registers. + + inline void loadI32(const Stk& src, RegI32 dest); + inline void loadI64(const Stk& src, RegI64 dest); +#if !defined(JS_PUNBOX64) + inline void loadI64Low(const Stk& src, RegI32 dest); + inline void loadI64High(const Stk& src, RegI32 dest); +#endif + inline void loadF64(const Stk& src, RegF64 dest); + inline void loadF32(const Stk& src, RegF32 dest); +#ifdef ENABLE_WASM_SIMD + inline void loadV128(const Stk& src, RegV128 dest); +#endif + inline void loadRef(const Stk& src, RegRef dest); + + ////////////////////////////////////////////////////////////////////// + // + // Value stack: stack management. + + // Flush all local and register value stack elements to memory. + inline void sync(); + + // Save a register on the value stack temporarily. + void saveTempPtr(const RegPtr& r); + + // Restore a temporarily saved register from the value stack. + void restoreTempPtr(const RegPtr& r); + + // This is an optimization used to avoid calling sync for setLocal: if the + // local does not exist unresolved on the value stack then we can skip the + // sync. + inline bool hasLocal(uint32_t slot); + + // Sync the local if necessary. (This currently syncs everything if a sync is + // needed at all.) + inline void syncLocal(uint32_t slot); + + // Return the amount of execution stack consumed by the top numval + // values on the value stack. + inline size_t stackConsumed(size_t numval); + + // Drop one value off the stack, possibly also moving the physical stack + // pointer. + inline void dropValue(); + +#ifdef DEBUG + // Check that we're not leaking registers by comparing the + // state of the stack + available registers with the set of + // all available registers. + + // Call this between opcodes. + void performRegisterLeakCheck(); + + // This can be called at any point, really, but typically just after + // performRegisterLeakCheck(). + void assertStackInvariants() const; + + // Count the number of memory references on the value stack. + inline size_t countMemRefsOnStk(); + + // Print the stack to stderr. + void showStack(const char* who) const; +#endif + + ////////////////////////////////////////////////////////////////////// + // + // Value stack: pushers of values. + + // Push a register onto the value stack. + inline void pushAny(AnyReg r); + inline void pushI32(RegI32 r); + inline void pushI64(RegI64 r); + inline void pushRef(RegRef r); + inline void pushPtr(RegPtr r); + inline void pushF64(RegF64 r); + inline void pushF32(RegF32 r); +#ifdef ENABLE_WASM_SIMD + inline void pushV128(RegV128 r); +#endif + + // Template variation of the foregoing, for use by templated emitters. + template <typename RegType> + inline void push(RegType item); + + // Push a constant value onto the stack. pushI32 can also take uint32_t, and + // pushI64 can take uint64_t; the semantics are the same. Appropriate sign + // extension for a 32-bit value on a 64-bit architecture happens when the + // value is popped, see the definition of moveImm32. + inline void pushI32(int32_t v); + inline void pushI64(int64_t v); + inline void pushRef(intptr_t v); + inline void pushPtr(intptr_t v); + inline void pushF64(double v); + inline void pushF32(float v); +#ifdef ENABLE_WASM_SIMD + inline void pushV128(V128 v); +#endif + inline void pushConstRef(intptr_t v); + + // Push the local slot onto the stack. The slot will not be read here; it + // will be read when it is consumed, or when a side effect to the slot forces + // its value to be saved. + inline void pushLocalI32(uint32_t slot); + inline void pushLocalI64(uint32_t slot); + inline void pushLocalRef(uint32_t slot); + inline void pushLocalF64(uint32_t slot); + inline void pushLocalF32(uint32_t slot); +#ifdef ENABLE_WASM_SIMD + inline void pushLocalV128(uint32_t slot); +#endif + + // Push an U32 as an I64, zero-extending it in the process + inline void pushU32AsI64(RegI32 rs); + + ////////////////////////////////////////////////////////////////////// + // + // Value stack: poppers and peekers of values. + + // Pop some value off the stack. + inline AnyReg popAny(); + inline AnyReg popAny(AnyReg specific); + + // Call only from other popI32() variants. v must be the stack top. May pop + // the CPU stack. + inline void popI32(const Stk& v, RegI32 dest); + + [[nodiscard]] inline RegI32 popI32(); + inline RegI32 popI32(RegI32 specific); + +#ifdef ENABLE_WASM_SIMD + // Call only from other popV128() variants. v must be the stack top. May pop + // the CPU stack. + inline void popV128(const Stk& v, RegV128 dest); + + [[nodiscard]] inline RegV128 popV128(); + inline RegV128 popV128(RegV128 specific); +#endif + + // Call only from other popI64() variants. v must be the stack top. May pop + // the CPU stack. + inline void popI64(const Stk& v, RegI64 dest); + + [[nodiscard]] inline RegI64 popI64(); + inline RegI64 popI64(RegI64 specific); + + // Call only from other popRef() variants. v must be the stack top. May pop + // the CPU stack. + inline void popRef(const Stk& v, RegRef dest); + + inline RegRef popRef(RegRef specific); + [[nodiscard]] inline RegRef popRef(); + + // Call only from other popPtr() variants. v must be the stack top. May pop + // the CPU stack. + inline void popPtr(const Stk& v, RegPtr dest); + + inline RegPtr popPtr(RegPtr specific); + [[nodiscard]] inline RegPtr popPtr(); + + // Call only from other popF64() variants. v must be the stack top. May pop + // the CPU stack. + inline void popF64(const Stk& v, RegF64 dest); + + [[nodiscard]] inline RegF64 popF64(); + inline RegF64 popF64(RegF64 specific); + + // Call only from other popF32() variants. v must be the stack top. May pop + // the CPU stack. + inline void popF32(const Stk& v, RegF32 dest); + + [[nodiscard]] inline RegF32 popF32(); + inline RegF32 popF32(RegF32 specific); + + // Templated variation of the foregoing, for use by templated emitters. + template <typename RegType> + inline RegType pop(); + + // Constant poppers will return true and pop the value if the stack top is a + // constant of the appropriate type; otherwise pop nothing and return false. + [[nodiscard]] inline bool hasConst() const; + [[nodiscard]] inline bool popConst(int32_t* c); + [[nodiscard]] inline bool popConst(int64_t* c); + [[nodiscard]] inline bool peekConst(int32_t* c); + [[nodiscard]] inline bool peekConst(int64_t* c); + [[nodiscard]] inline bool peek2xConst(int32_t* c0, int32_t* c1); + [[nodiscard]] inline bool popConstPositivePowerOfTwo(int32_t* c, + uint_fast8_t* power, + int32_t cutoff); + [[nodiscard]] inline bool popConstPositivePowerOfTwo(int64_t* c, + uint_fast8_t* power, + int64_t cutoff); + + // Shorthand: Pop r1, then r0. + inline void pop2xI32(RegI32* r0, RegI32* r1); + inline void pop2xI64(RegI64* r0, RegI64* r1); + inline void pop2xF32(RegF32* r0, RegF32* r1); + inline void pop2xF64(RegF64* r0, RegF64* r1); +#ifdef ENABLE_WASM_SIMD + inline void pop2xV128(RegV128* r0, RegV128* r1); +#endif + inline void pop2xRef(RegRef* r0, RegRef* r1); + + // Pop to a specific register + inline RegI32 popI32ToSpecific(RegI32 specific); + inline RegI64 popI64ToSpecific(RegI64 specific); + +#ifdef JS_CODEGEN_ARM + // Pop an I64 as a valid register pair. + inline RegI64 popI64Pair(); +#endif + + // Pop an I64 but narrow it and return the narrowed part. + inline RegI32 popI64ToI32(); + inline RegI32 popI64ToSpecificI32(RegI32 specific); + + // Pop an I32 or I64 as an I64. The value is zero extended out to 64-bits. + inline RegI64 popIndexToInt64(IndexType indexType); + + // Pop the stack until it has the desired size, but do not move the physical + // stack pointer. + inline void popValueStackTo(uint32_t stackSize); + + // Pop the given number of elements off the value stack, but do not move + // the physical stack pointer. + inline void popValueStackBy(uint32_t items); + + // Peek into the stack at relativeDepth from the top. + inline Stk& peek(uint32_t relativeDepth); + + // Peek the reference value at the specified depth and load it into a + // register. + inline void peekRefAt(uint32_t depth, RegRef dest); + + // Peek at the value on the top of the stack and return true if it is a Local + // of any type. + [[nodiscard]] inline bool peekLocal(uint32_t* local); + + //////////////////////////////////////////////////////////////////////////// + // + // Block parameters and results. + // + // Blocks may have multiple parameters and multiple results. Blocks can also + // be the target of branches: the entry for loops, and the exit for + // non-loops. + // + // Passing multiple values to a non-branch target (i.e., the entry of a + // "block") falls out naturally: any items on the value stack can flow + // directly from one block to another. + // + // However, for branch targets, we need to allocate well-known locations for + // the branch values. The approach taken in the baseline compiler is to + // allocate registers to the top N values (currently N=1), and then stack + // locations for the rest. + // + + // Types of result registers that interest us for result-manipulating + // functions. + enum class ResultRegKind { + // General and floating result registers. + All, + + // General result registers only. + OnlyGPRs + }; + + // This is a flag ultimately intended for popBlockResults() that specifies how + // the CPU stack should be handled after the result values have been + // processed. + enum class ContinuationKind { + // Adjust the stack for a fallthrough: do nothing. + Fallthrough, + + // Adjust the stack for a jump: make the stack conform to the + // expected stack at the target + Jump + }; + + // TODO: It's definitely disputable whether the result register management is + // hot enough to warrant inlining at the outermost level. + + inline void needResultRegisters(ResultType type, ResultRegKind which); +#ifdef JS_64BIT + inline void widenInt32ResultRegisters(ResultType type); +#endif + inline void freeResultRegisters(ResultType type, ResultRegKind which); + inline void needIntegerResultRegisters(ResultType type); + inline void freeIntegerResultRegisters(ResultType type); + inline void needResultRegisters(ResultType type); + inline void freeResultRegisters(ResultType type); + void assertResultRegistersAvailable(ResultType type); + inline void captureResultRegisters(ResultType type); + inline void captureCallResultRegisters(ResultType type); + + void popRegisterResults(ABIResultIter& iter); + void popStackResults(ABIResultIter& iter, StackHeight stackBase); + + void popBlockResults(ResultType type, StackHeight stackBase, + ContinuationKind kind); + + // This function is similar to popBlockResults, but additionally handles the + // implicit exception pointer that is pushed to the value stack on entry to + // a catch handler by dropping it appropriately. + void popCatchResults(ResultType type, StackHeight stackBase); + + Stk captureStackResult(const ABIResult& result, StackHeight resultsBase, + uint32_t stackResultBytes); + + [[nodiscard]] bool pushResults(ResultType type, StackHeight resultsBase); + [[nodiscard]] bool pushBlockResults(ResultType type); + + // A combination of popBlockResults + pushBlockResults, used when entering a + // block with a control-flow join (loops) or split (if) to shuffle the + // fallthrough block parameters into the locations expected by the + // continuation. + // + // This function should only be called when entering a block with a + // control-flow join at the entry, where there are no live temporaries in + // the current block. + [[nodiscard]] bool topBlockParams(ResultType type); + + // A combination of popBlockResults + pushBlockResults, used before branches + // where we don't know the target (br_if / br_table). If and when the branch + // is taken, the stack results will be shuffled down into place. For br_if + // that has fallthrough, the parameters for the untaken branch flow through to + // the continuation. + [[nodiscard]] bool topBranchParams(ResultType type, StackHeight* height); + + // Conditional branches with fallthrough are preceded by a topBranchParams, so + // we know that there are no stack results that need to be materialized. In + // that case, we can just shuffle the whole block down before popping the + // stack. + void shuffleStackResultsBeforeBranch(StackHeight srcHeight, + StackHeight destHeight, ResultType type); + + // If in debug mode, adds LeaveFrame breakpoint. + bool insertDebugCollapseFrame(); + + ////////////////////////////////////////////////////////////////////// + // + // Stack maps + + // Various methods for creating a stackmap. Stackmaps are indexed by the + // lowest address of the instruction immediately *after* the instruction of + // interest. In practice that means either: the return point of a call, the + // instruction immediately after a trap instruction (the "resume" + // instruction), or the instruction immediately following a no-op (when + // debugging is enabled). + + // Create a vanilla stackmap. + [[nodiscard]] bool createStackMap(const char* who); + + // Create a stackmap as vanilla, but for a custom assembler offset. + [[nodiscard]] bool createStackMap(const char* who, + CodeOffset assemblerOffset); + + // Create a stack map as vanilla, and note the presence of a ref-typed + // DebugFrame on the stack. + [[nodiscard]] bool createStackMap( + const char* who, HasDebugFrameWithLiveRefs debugFrameWithLiveRefs); + + // The most general stackmap construction. + [[nodiscard]] bool createStackMap( + const char* who, const ExitStubMapVector& extras, + uint32_t assemblerOffset, + HasDebugFrameWithLiveRefs debugFrameWithLiveRefs); + + //////////////////////////////////////////////////////////// + // + // Control stack + + inline void initControl(Control& item, ResultType params); + inline Control& controlItem(); + inline Control& controlItem(uint32_t relativeDepth); + inline Control& controlOutermost(); + inline LabelKind controlKind(uint32_t relativeDepth); + + //////////////////////////////////////////////////////////// + // + // Debugger API + + // Insert a breakpoint almost anywhere. This will create a call, with all the + // overhead that entails. + void insertBreakablePoint(CallSiteDesc::Kind kind); + + // Insert code at the end of a function for breakpoint filtering. + void insertBreakpointStub(); + + // Debugger API used at the return point: shuffle register return values off + // to memory for the debugger to see; and get them back again. + void saveRegisterReturnValues(const ResultType& resultType); + void restoreRegisterReturnValues(const ResultType& resultType); + + ////////////////////////////////////////////////////////////////////// + // + // Function prologue and epilogue. + + // Set up and tear down frame, execute prologue and epilogue. + [[nodiscard]] bool beginFunction(); + [[nodiscard]] bool endFunction(); + + // Move return values to memory before returning, as appropriate + void popStackReturnValues(const ResultType& resultType); + + ////////////////////////////////////////////////////////////////////// + // + // Calls. + + void beginCall(FunctionCall& call, UseABI useABI, + RestoreRegisterStateAndRealm restoreRegisterStateAndRealm); + void endCall(FunctionCall& call, size_t stackSpace); + void startCallArgs(size_t stackArgAreaSizeUnaligned, FunctionCall* call); + ABIArg reservePointerArgument(FunctionCall* call); + void passArg(ValType type, const Stk& arg, FunctionCall* call); + CodeOffset callDefinition(uint32_t funcIndex, const FunctionCall& call); + CodeOffset callSymbolic(SymbolicAddress callee, const FunctionCall& call); + + // Precondition for the call*() methods: sync() + + bool callIndirect(uint32_t funcTypeIndex, uint32_t tableIndex, + const Stk& indexVal, const FunctionCall& call, + bool tailCall, CodeOffset* fastCallOffset, + CodeOffset* slowCallOffset); + CodeOffset callImport(unsigned instanceDataOffset, const FunctionCall& call); +#ifdef ENABLE_WASM_FUNCTION_REFERENCES + void callRef(const Stk& calleeRef, const FunctionCall& call, + CodeOffset* fastCallOffset, CodeOffset* slowCallOffset); +# ifdef ENABLE_WASM_TAIL_CALLS + void returnCallRef(const Stk& calleeRef, const FunctionCall& call, + const FuncType* funcType); +# endif +#endif + CodeOffset builtinCall(SymbolicAddress builtin, const FunctionCall& call); + CodeOffset builtinInstanceMethodCall(const SymbolicAddressSignature& builtin, + const ABIArg& instanceArg, + const FunctionCall& call); + [[nodiscard]] bool pushCallResults(const FunctionCall& call, ResultType type, + const StackResultsLoc& loc); + + // Helpers to pick up the returned value from the return register. + inline RegI32 captureReturnedI32(); + inline RegI64 captureReturnedI64(); + inline RegF32 captureReturnedF32(const FunctionCall& call); + inline RegF64 captureReturnedF64(const FunctionCall& call); +#ifdef ENABLE_WASM_SIMD + inline RegV128 captureReturnedV128(const FunctionCall& call); +#endif + inline RegRef captureReturnedRef(); + + ////////////////////////////////////////////////////////////////////// + // + // Register-to-register moves. These emit nothing if src == dest. + + inline void moveI32(RegI32 src, RegI32 dest); + inline void moveI64(RegI64 src, RegI64 dest); + inline void moveRef(RegRef src, RegRef dest); + inline void movePtr(RegPtr src, RegPtr dest); + inline void moveF64(RegF64 src, RegF64 dest); + inline void moveF32(RegF32 src, RegF32 dest); +#ifdef ENABLE_WASM_SIMD + inline void moveV128(RegV128 src, RegV128 dest); +#endif + + template <typename RegType> + inline void move(RegType src, RegType dest); + + ////////////////////////////////////////////////////////////////////// + // + // Immediate-to-register moves. + // + // The compiler depends on moveImm32() clearing the high bits of a 64-bit + // register on 64-bit systems except MIPS64 And LoongArch64 where high bits + // are sign extended from lower bits, see doc block "64-bit GPRs carrying + // 32-bit values" in MacroAssembler.h. + + inline void moveImm32(int32_t v, RegI32 dest); + inline void moveImm64(int64_t v, RegI64 dest); + inline void moveImmRef(intptr_t v, RegRef dest); + + ////////////////////////////////////////////////////////////////////// + // + // Sundry low-level code generators. + + // Check the interrupt flag, trap if it is set. + [[nodiscard]] bool addInterruptCheck(); + + // Check that the value is not zero, trap if it is. + void checkDivideByZero(RegI32 rhs); + void checkDivideByZero(RegI64 r); + + // Check that a signed division will not overflow, trap or flush-to-zero if it + // will according to `zeroOnOverflow`. + void checkDivideSignedOverflow(RegI32 rhs, RegI32 srcDest, Label* done, + bool zeroOnOverflow); + void checkDivideSignedOverflow(RegI64 rhs, RegI64 srcDest, Label* done, + bool zeroOnOverflow); + + // Emit a jump table to be used by tableSwitch() + void jumpTable(const LabelVector& labels, Label* theTable); + + // Emit a table switch, `theTable` is the jump table. + void tableSwitch(Label* theTable, RegI32 switchValue, Label* dispatchCode); + + // Compare i64 and set an i32 boolean result according to the condition. + inline void cmp64Set(Assembler::Condition cond, RegI64 lhs, RegI64 rhs, + RegI32 dest); + + // Round floating to integer. + [[nodiscard]] inline bool supportsRoundInstruction(RoundingMode mode); + inline void roundF32(RoundingMode roundingMode, RegF32 f0); + inline void roundF64(RoundingMode roundingMode, RegF64 f0); + + // These are just wrappers around assembler functions, but without + // type-specific names, and using our register abstractions for better type + // discipline. + inline void branchTo(Assembler::DoubleCondition c, RegF64 lhs, RegF64 rhs, + Label* l); + inline void branchTo(Assembler::DoubleCondition c, RegF32 lhs, RegF32 rhs, + Label* l); + inline void branchTo(Assembler::Condition c, RegI32 lhs, RegI32 rhs, + Label* l); + inline void branchTo(Assembler::Condition c, RegI32 lhs, Imm32 rhs, Label* l); + inline void branchTo(Assembler::Condition c, RegI64 lhs, RegI64 rhs, + Label* l); + inline void branchTo(Assembler::Condition c, RegI64 lhs, Imm64 rhs, Label* l); + inline void branchTo(Assembler::Condition c, RegRef lhs, ImmWord rhs, + Label* l); + + // Helpers for accessing Instance::baselineScratchWords_. Note that Word + // and I64 versions of these routines access the same area and it is up to + // the caller to use it in some way which makes sense. + + // Store/load `r`, a machine word, to/from the `index`th scratch storage + // slot in the current Instance. `instancePtr` must point at the current + // Instance; it will not be modified. For ::stashWord, `r` must not be the + // same as `instancePtr`. + void stashWord(RegPtr instancePtr, size_t index, RegPtr r); + void unstashWord(RegPtr instancePtr, size_t index, RegPtr r); + +#ifdef JS_CODEGEN_X86 + // Store r in instance scratch storage after first loading the instance from + // the frame into the regForInstance. regForInstance must be neither of the + // registers in r. + void stashI64(RegPtr regForInstance, RegI64 r); + + // Load r from the instance scratch storage after first loading the instance + // from the frame into the regForInstance. regForInstance can be one of the + // registers in r. + void unstashI64(RegPtr regForInstance, RegI64 r); +#endif + + ////////////////////////////////////////////////////////////////////// + // + // Code generators for actual operations. + + template <typename RegType, typename IntType> + void quotientOrRemainder(RegType rs, RegType rsd, RegType reserved, + IsUnsigned isUnsigned, ZeroOnOverflow zeroOnOverflow, + bool isConst, IntType c, + void (*operate)(MacroAssembler&, RegType, RegType, + RegType, IsUnsigned)); + + [[nodiscard]] bool truncateF32ToI32(RegF32 src, RegI32 dest, + TruncFlags flags); + [[nodiscard]] bool truncateF64ToI32(RegF64 src, RegI32 dest, + TruncFlags flags); + +#ifndef RABALDR_FLOAT_TO_I64_CALLOUT + [[nodiscard]] RegF64 needTempForFloatingToI64(TruncFlags flags); + [[nodiscard]] bool truncateF32ToI64(RegF32 src, RegI64 dest, TruncFlags flags, + RegF64 temp); + [[nodiscard]] bool truncateF64ToI64(RegF64 src, RegI64 dest, TruncFlags flags, + RegF64 temp); +#endif // RABALDR_FLOAT_TO_I64_CALLOUT + +#ifndef RABALDR_I64_TO_FLOAT_CALLOUT + [[nodiscard]] RegI32 needConvertI64ToFloatTemp(ValType to, bool isUnsigned); + void convertI64ToF32(RegI64 src, bool isUnsigned, RegF32 dest, RegI32 temp); + void convertI64ToF64(RegI64 src, bool isUnsigned, RegF64 dest, RegI32 temp); +#endif // RABALDR_I64_TO_FLOAT_CALLOUT + + ////////////////////////////////////////////////////////////////////// + // + // Global variable access. + + Address addressOfGlobalVar(const GlobalDesc& global, RegPtr tmp); + + ////////////////////////////////////////////////////////////////////// + // + // Table access. + + Address addressOfTableField(uint32_t tableIndex, uint32_t fieldOffset, + RegPtr instance); + void loadTableLength(uint32_t tableIndex, RegPtr instance, RegI32 length); + void loadTableElements(uint32_t tableIndex, RegPtr instance, RegPtr elements); + + ////////////////////////////////////////////////////////////////////// + // + // Heap access. + + void bceCheckLocal(MemoryAccessDesc* access, AccessCheck* check, + uint32_t local); + void bceLocalIsUpdated(uint32_t local); + + // Fold offsets into ptr and bounds check as necessary. The instance will be + // valid in cases where it's needed. + template <typename RegIndexType> + void prepareMemoryAccess(MemoryAccessDesc* access, AccessCheck* check, + RegPtr instance, RegIndexType ptr); + + void branchAddNoOverflow(uint64_t offset, RegI32 ptr, Label* ok); + void branchTestLowZero(RegI32 ptr, Imm32 mask, Label* ok); + void boundsCheck4GBOrLargerAccess(uint32_t memoryIndex, RegPtr instance, + RegI32 ptr, Label* ok); + void boundsCheckBelow4GBAccess(uint32_t memoryIndex, RegPtr instance, + RegI32 ptr, Label* ok); + + void branchAddNoOverflow(uint64_t offset, RegI64 ptr, Label* ok); + void branchTestLowZero(RegI64 ptr, Imm32 mask, Label* ok); + void boundsCheck4GBOrLargerAccess(uint32_t memoryIndex, RegPtr instance, + RegI64 ptr, Label* ok); + void boundsCheckBelow4GBAccess(uint32_t memoryIndex, RegPtr instance, + RegI64 ptr, Label* ok); + + // Some consumers depend on the returned Address not incorporating instance, + // as instance may be the scratch register. + template <typename RegIndexType> + Address prepareAtomicMemoryAccess(MemoryAccessDesc* access, + AccessCheck* check, RegPtr instance, + RegIndexType ptr); + + template <typename RegIndexType> + void computeEffectiveAddress(MemoryAccessDesc* access); + + [[nodiscard]] bool needInstanceForAccess(const MemoryAccessDesc* access, + const AccessCheck& check); + + // ptr and dest may be the same iff dest is I32. + // This may destroy ptr even if ptr and dest are not the same. + void executeLoad(MemoryAccessDesc* access, AccessCheck* check, + RegPtr instance, RegPtr memoryBase, RegI32 ptr, AnyReg dest, + RegI32 temp); + void load(MemoryAccessDesc* access, AccessCheck* check, RegPtr instance, + RegPtr memoryBase, RegI32 ptr, AnyReg dest, RegI32 temp); +#ifdef ENABLE_WASM_MEMORY64 + void load(MemoryAccessDesc* access, AccessCheck* check, RegPtr instance, + RegPtr memoryBase, RegI64 ptr, AnyReg dest, RegI64 temp); +#endif + + template <typename RegType> + void doLoadCommon(MemoryAccessDesc* access, AccessCheck check, ValType type); + + void loadCommon(MemoryAccessDesc* access, AccessCheck check, ValType type); + + // ptr and src must not be the same register. + // This may destroy ptr and src. + void executeStore(MemoryAccessDesc* access, AccessCheck* check, + RegPtr instance, RegPtr memoryBase, RegI32 ptr, AnyReg src, + RegI32 temp); + void store(MemoryAccessDesc* access, AccessCheck* check, RegPtr instance, + RegPtr memoryBase, RegI32 ptr, AnyReg src, RegI32 temp); +#ifdef ENABLE_WASM_MEMORY64 + void store(MemoryAccessDesc* access, AccessCheck* check, RegPtr instance, + RegPtr memoryBase, RegI64 ptr, AnyReg src, RegI64 temp); +#endif + + template <typename RegType> + void doStoreCommon(MemoryAccessDesc* access, AccessCheck check, + ValType resultType); + + void storeCommon(MemoryAccessDesc* access, AccessCheck check, + ValType resultType); + + void atomicLoad(MemoryAccessDesc* access, ValType type); +#if !defined(JS_64BIT) + template <typename RegIndexType> + void atomicLoad64(MemoryAccessDesc* desc); +#endif + + void atomicStore(MemoryAccessDesc* access, ValType type); + + void atomicRMW(MemoryAccessDesc* access, ValType type, AtomicOp op); + template <typename RegIndexType> + void atomicRMW32(MemoryAccessDesc* access, ValType type, AtomicOp op); + template <typename RegIndexType> + void atomicRMW64(MemoryAccessDesc* access, ValType type, AtomicOp op); + + void atomicXchg(MemoryAccessDesc* access, ValType type); + template <typename RegIndexType> + void atomicXchg64(MemoryAccessDesc* access, WantResult wantResult); + template <typename RegIndexType> + void atomicXchg32(MemoryAccessDesc* access, ValType type); + + void atomicCmpXchg(MemoryAccessDesc* access, ValType type); + template <typename RegIndexType> + void atomicCmpXchg32(MemoryAccessDesc* access, ValType type); + template <typename RegIndexType> + void atomicCmpXchg64(MemoryAccessDesc* access, ValType type); + + template <typename RegType> + RegType popConstMemoryAccess(MemoryAccessDesc* access, AccessCheck* check); + template <typename RegType> + RegType popMemoryAccess(MemoryAccessDesc* access, AccessCheck* check); + + void pushHeapBase(uint32_t memoryIndex); + + //////////////////////////////////////////////////////////////////////////// + // + // Platform-specific popping and register targeting. + + // The simple popping methods pop values into targeted registers; the caller + // can free registers using standard functions. These are always called + // popXForY where X says something about types and Y something about the + // operation being targeted. + + RegI32 needRotate64Temp(); + void popAndAllocateForDivAndRemI32(RegI32* r0, RegI32* r1, RegI32* reserved); + void popAndAllocateForMulI64(RegI64* r0, RegI64* r1, RegI32* temp); +#ifndef RABALDR_INT_DIV_I64_CALLOUT + void popAndAllocateForDivAndRemI64(RegI64* r0, RegI64* r1, RegI64* reserved, + IsRemainder isRemainder); +#endif + RegI32 popI32RhsForShift(); + RegI32 popI32RhsForShiftI64(); + RegI64 popI64RhsForShift(); + RegI32 popI32RhsForRotate(); + RegI64 popI64RhsForRotate(); + void popI32ForSignExtendI64(RegI64* r0); + void popI64ForSignExtendI64(RegI64* r0); + + //////////////////////////////////////////////////////////// + // + // Sundry helpers. + + // Retrieve the current bytecodeOffset. + inline BytecodeOffset bytecodeOffset() const; + + // Generate a trap instruction for the current bytecodeOffset. + inline void trap(Trap t) const; + + // Abstracted helper for throwing, used for throw, rethrow, and rethrowing + // at the end of a series of catch blocks (if none matched the exception). + [[nodiscard]] bool throwFrom(RegRef exn); + + // Load the specified tag object from the Instance. + void loadTag(RegPtr instance, uint32_t tagIndex, RegRef tagDst); + + // Load the pending exception state from the Instance and then reset it. + void consumePendingException(RegPtr instance, RegRef* exnDst, RegRef* tagDst); + + [[nodiscard]] bool startTryNote(size_t* tryNoteIndex); + void finishTryNote(size_t tryNoteIndex); + + //////////////////////////////////////////////////////////// + // + // Barriers support. + + // This emits a GC pre-write barrier. The pre-barrier is needed when we + // replace a member field with a new value, and the previous field value + // might have no other referents, and incremental GC is ongoing. The field + // might belong to an object or be a stack slot or a register or a heap + // allocated value. + // + // let obj = { field: previousValue }; + // obj.field = newValue; // previousValue must be marked with a pre-barrier. + // + // The `valueAddr` is the address of the location that we are about to + // update. This function preserves that register. + void emitPreBarrier(RegPtr valueAddr); + + // This emits a GC post-write barrier. The post-barrier is needed when we + // replace a member field with a new value, the new value is in the nursery, + // and the containing object is a tenured object. The field must then be + // added to the store buffer so that the nursery can be correctly collected. + // The field might belong to an object or be a stack slot or a register or a + // heap allocated value. + // + // For the difference between 'precise' and 'imprecise', look at the + // documentation on PostBarrierKind. + // + // `object` is a pointer to the object that contains the field. It is used, if + // present, to skip adding a store buffer entry when the containing object is + // in the nursery. This register is preserved by this function. + // `valueAddr` is the address of the location that we are writing to. This + // register is consumed by this function. + // `prevValue` is the value that existed in the field before `value` was + // stored. This register is consumed by this function. + // `value` is the value that was stored in the field. This register is + // preserved by this function. + [[nodiscard]] bool emitPostBarrierImprecise(const Maybe<RegRef>& object, + RegPtr valueAddr, RegRef value); + [[nodiscard]] bool emitPostBarrierPrecise(const Maybe<RegRef>& object, + RegPtr valueAddr, RegRef prevValue, + RegRef value); + + // Emits a store to a JS object pointer at the address `valueAddr`, which is + // inside the GC cell `object`. + // + // Preserves `object` and `value`. Consumes `valueAddr`. + [[nodiscard]] bool emitBarrieredStore(const Maybe<RegRef>& object, + RegPtr valueAddr, RegRef value, + PreBarrierKind preBarrierKind, + PostBarrierKind postBarrierKind); + + // Emits a store of nullptr to a JS object pointer at the address valueAddr. + // Preserves `valueAddr`. + void emitBarrieredClear(RegPtr valueAddr); + + //////////////////////////////////////////////////////////// + // + // Machinery for optimized conditional branches. See comments in the + // implementation. + + void setLatentCompare(Assembler::Condition compareOp, ValType operandType); + void setLatentCompare(Assembler::DoubleCondition compareOp, + ValType operandType); + void setLatentEqz(ValType operandType); + bool hasLatentOp() const; + void resetLatentOp(); + // Jump to the given branch, passing results, if the condition, `cond` + // matches between `lhs` and `rhs. + template <typename Cond, typename Lhs, typename Rhs> + [[nodiscard]] bool jumpConditionalWithResults(BranchState* b, Cond cond, + Lhs lhs, Rhs rhs); +#ifdef ENABLE_WASM_GC + // Jump to the given branch, passing results, if the WasmGcObject, `object`, + // is a subtype of `destType`. + [[nodiscard]] bool jumpConditionalWithResults(BranchState* b, RegRef object, + RefType sourceType, + RefType destType, + bool onSuccess); +#endif + template <typename Cond> + [[nodiscard]] bool sniffConditionalControlCmp(Cond compareOp, + ValType operandType); + [[nodiscard]] bool sniffConditionalControlEqz(ValType operandType); + void emitBranchSetup(BranchState* b); + [[nodiscard]] bool emitBranchPerform(BranchState* b); + + ////////////////////////////////////////////////////////////////////// + + [[nodiscard]] bool emitBody(); + [[nodiscard]] bool emitBlock(); + [[nodiscard]] bool emitLoop(); + [[nodiscard]] bool emitIf(); + [[nodiscard]] bool emitElse(); + // Used for common setup for catch and catch_all. + void emitCatchSetup(LabelKind kind, Control& tryCatch, + const ResultType& resultType); + // Helper function used to generate landing pad code for the special + // case in which `delegate` jumps to a function's body block. + [[nodiscard]] bool emitBodyDelegateThrowPad(); + + [[nodiscard]] bool emitTry(); + [[nodiscard]] bool emitTryTable(); + [[nodiscard]] bool emitCatch(); + [[nodiscard]] bool emitCatchAll(); + [[nodiscard]] bool emitDelegate(); + [[nodiscard]] bool emitThrow(); + [[nodiscard]] bool emitThrowRef(); + [[nodiscard]] bool emitRethrow(); + [[nodiscard]] bool emitEnd(); + [[nodiscard]] bool emitBr(); + [[nodiscard]] bool emitBrIf(); + [[nodiscard]] bool emitBrTable(); + [[nodiscard]] bool emitDrop(); + [[nodiscard]] bool emitReturn(); + + // A flag passed to emitCallArgs, describing how the value stack is laid out. + enum class CalleeOnStack { + // After the arguments to the call, there is a callee pushed onto value + // stack. This is only the case for callIndirect. To get the arguments to + // the call, emitCallArgs has to reach one element deeper into the value + // stack, to skip the callee. + True, + + // No callee on the stack. + False + }; + + // The typename T for emitCallArgs can be one of the following: + // NormalCallResults, TailCallResults, or NoCallResults. + template <typename T> + [[nodiscard]] bool emitCallArgs(const ValTypeVector& argTypes, T results, + FunctionCall* baselineCall, + CalleeOnStack calleeOnStack); + + [[nodiscard]] bool emitCall(); + [[nodiscard]] bool emitReturnCall(); + [[nodiscard]] bool emitCallIndirect(); + [[nodiscard]] bool emitReturnCallIndirect(); + [[nodiscard]] bool emitUnaryMathBuiltinCall(SymbolicAddress callee, + ValType operandType); + [[nodiscard]] bool emitGetLocal(); + [[nodiscard]] bool emitSetLocal(); + [[nodiscard]] bool emitTeeLocal(); + [[nodiscard]] bool emitGetGlobal(); + [[nodiscard]] bool emitSetGlobal(); + [[nodiscard]] RegPtr maybeLoadMemoryBaseForAccess( + RegPtr instance, const MemoryAccessDesc* access); + [[nodiscard]] RegPtr maybeLoadInstanceForAccess( + const MemoryAccessDesc* access, const AccessCheck& check); + [[nodiscard]] RegPtr maybeLoadInstanceForAccess( + const MemoryAccessDesc* access, const AccessCheck& check, + RegPtr specific); + [[nodiscard]] bool emitLoad(ValType type, Scalar::Type viewType); + [[nodiscard]] bool emitStore(ValType resultType, Scalar::Type viewType); + [[nodiscard]] bool emitSelect(bool typed); + + template <bool isSetLocal> + [[nodiscard]] bool emitSetOrTeeLocal(uint32_t slot); + + [[nodiscard]] bool endBlock(ResultType type); + [[nodiscard]] bool endIfThen(ResultType type); + [[nodiscard]] bool endIfThenElse(ResultType type); + [[nodiscard]] bool endTryCatch(ResultType type); + [[nodiscard]] bool endTryTable(ResultType type); + + void doReturn(ContinuationKind kind); + void pushReturnValueOfCall(const FunctionCall& call, MIRType type); + + [[nodiscard]] bool pushStackResultsForCall(const ResultType& type, + RegPtr temp, StackResultsLoc* loc); + void popStackResultsAfterCall(const StackResultsLoc& results, + uint32_t stackArgBytes); + + void emitCompareI32(Assembler::Condition compareOp, ValType compareType); + void emitCompareI64(Assembler::Condition compareOp, ValType compareType); + void emitCompareF32(Assembler::DoubleCondition compareOp, + ValType compareType); + void emitCompareF64(Assembler::DoubleCondition compareOp, + ValType compareType); + void emitCompareRef(Assembler::Condition compareOp, ValType compareType); + + template <typename CompilerType> + inline CompilerType& selectCompiler(); + + template <typename SourceType, typename DestType> + inline void emitUnop(void (*op)(MacroAssembler& masm, SourceType rs, + DestType rd)); + + template <typename SourceType, typename DestType, typename TempType> + inline void emitUnop(void (*op)(MacroAssembler& masm, SourceType rs, + DestType rd, TempType temp)); + + template <typename SourceType, typename DestType, typename ImmType> + inline void emitUnop(ImmType immediate, void (*op)(MacroAssembler&, ImmType, + SourceType, DestType)); + + template <typename CompilerType, typename RegType> + inline void emitUnop(void (*op)(CompilerType& compiler, RegType rsd)); + + template <typename RegType, typename TempType> + inline void emitUnop(void (*op)(BaseCompiler& bc, RegType rsd, TempType rt), + TempType (*getSpecializedTemp)(BaseCompiler& bc)); + + template <typename CompilerType, typename RhsType, typename LhsDestType> + inline void emitBinop(void (*op)(CompilerType& masm, RhsType src, + LhsDestType srcDest)); + + template <typename RhsDestType, typename LhsType> + inline void emitBinop(void (*op)(MacroAssembler& masm, RhsDestType src, + LhsType srcDest, RhsDestOp)); + + template <typename RhsType, typename LhsDestType, typename TempType> + inline void emitBinop(void (*)(MacroAssembler& masm, RhsType rs, + LhsDestType rsd, TempType temp)); + + template <typename RhsType, typename LhsDestType, typename TempType1, + typename TempType2> + inline void emitBinop(void (*)(MacroAssembler& masm, RhsType rs, + LhsDestType rsd, TempType1 temp1, + TempType2 temp2)); + + template <typename RhsType, typename LhsDestType, typename ImmType> + inline void emitBinop(ImmType immediate, void (*op)(MacroAssembler&, ImmType, + RhsType, LhsDestType)); + + template <typename RhsType, typename LhsDestType, typename ImmType, + typename TempType1, typename TempType2> + inline void emitBinop(ImmType immediate, + void (*op)(MacroAssembler&, ImmType, RhsType, + LhsDestType, TempType1 temp1, + TempType2 temp2)); + + template <typename CompilerType1, typename CompilerType2, typename RegType, + typename ImmType> + inline void emitBinop(void (*op)(CompilerType1& compiler1, RegType rs, + RegType rd), + void (*opConst)(CompilerType2& compiler2, ImmType c, + RegType rd), + RegType (BaseCompiler::*rhsPopper)() = nullptr); + + template <typename CompilerType, typename ValType> + inline void emitTernary(void (*op)(CompilerType&, ValType src0, ValType src1, + ValType srcDest)); + + template <typename CompilerType, typename ValType> + inline void emitTernary(void (*op)(CompilerType&, ValType src0, ValType src1, + ValType srcDest, ValType temp)); + + template <typename CompilerType, typename ValType> + inline void emitTernaryResultLast(void (*op)(CompilerType&, ValType src0, + ValType src1, ValType srcDest)); + + template <typename R> + [[nodiscard]] inline bool emitInstanceCallOp( + const SymbolicAddressSignature& fn, R reader); + + template <typename A1, typename R> + [[nodiscard]] inline bool emitInstanceCallOp( + const SymbolicAddressSignature& fn, R reader); + + template <typename A1, typename A2, typename R> + [[nodiscard]] inline bool emitInstanceCallOp( + const SymbolicAddressSignature& fn, R reader); + + void emitMultiplyI64(); + void emitQuotientI32(); + void emitQuotientU32(); + void emitRemainderI32(); + void emitRemainderU32(); +#ifdef RABALDR_INT_DIV_I64_CALLOUT + [[nodiscard]] bool emitDivOrModI64BuiltinCall(SymbolicAddress callee, + ValType operandType); +#else + void emitQuotientI64(); + void emitQuotientU64(); + void emitRemainderI64(); + void emitRemainderU64(); +#endif + void emitRotrI64(); + void emitRotlI64(); + void emitEqzI32(); + void emitEqzI64(); + template <TruncFlags flags> + [[nodiscard]] bool emitTruncateF32ToI32(); + template <TruncFlags flags> + [[nodiscard]] bool emitTruncateF64ToI32(); +#ifdef RABALDR_FLOAT_TO_I64_CALLOUT + [[nodiscard]] bool emitConvertFloatingToInt64Callout(SymbolicAddress callee, + ValType operandType, + ValType resultType); +#else + template <TruncFlags flags> + [[nodiscard]] bool emitTruncateF32ToI64(); + template <TruncFlags flags> + [[nodiscard]] bool emitTruncateF64ToI64(); +#endif + void emitExtendI64_8(); + void emitExtendI64_16(); + void emitExtendI64_32(); + void emitExtendI32ToI64(); + void emitExtendU32ToI64(); +#ifdef RABALDR_I64_TO_FLOAT_CALLOUT + [[nodiscard]] bool emitConvertInt64ToFloatingCallout(SymbolicAddress callee, + ValType operandType, + ValType resultType); +#else + void emitConvertU64ToF32(); + void emitConvertU64ToF64(); +#endif + void emitRound(RoundingMode roundingMode, ValType operandType); + + // Generate a call to the instance function denoted by `builtin`, passing as + // args the top elements of the compiler's value stack and optionally an + // Instance* too. The relationship between the top of stack and arg + // ordering is as follows. If the value stack looks like this: + // + // A <- least recently pushed + // B + // C <- most recently pushed + // + // then the called function is expected to have signature [if an Instance* + // is also to be passed]: + // + // static Instance::foo(Instance*, A, B, C) + // + // and the SymbolicAddressSignature::argTypes array will be + // + // {_PTR, _A, _B, _C, _END} // _PTR is for the Instance* + // + // (see WasmBuiltins.cpp). In short, the most recently pushed value is the + // rightmost argument to the function. + [[nodiscard]] bool emitInstanceCall(const SymbolicAddressSignature& builtin); + + [[nodiscard]] bool emitMemoryGrow(); + [[nodiscard]] bool emitMemorySize(); + + [[nodiscard]] bool emitRefFunc(); + [[nodiscard]] bool emitRefNull(); + [[nodiscard]] bool emitRefIsNull(); +#ifdef ENABLE_WASM_FUNCTION_REFERENCES + [[nodiscard]] bool emitRefAsNonNull(); + [[nodiscard]] bool emitBrOnNull(); + [[nodiscard]] bool emitBrOnNonNull(); + [[nodiscard]] bool emitCallRef(); + [[nodiscard]] bool emitReturnCallRef(); +#endif + + [[nodiscard]] bool emitAtomicCmpXchg(ValType type, Scalar::Type viewType); + [[nodiscard]] bool emitAtomicLoad(ValType type, Scalar::Type viewType); + [[nodiscard]] bool emitAtomicRMW(ValType type, Scalar::Type viewType, + AtomicOp op); + [[nodiscard]] bool emitAtomicStore(ValType type, Scalar::Type viewType); + [[nodiscard]] bool emitWait(ValType type, uint32_t byteSize); + [[nodiscard]] bool atomicWait(ValType type, MemoryAccessDesc* access); + [[nodiscard]] bool emitWake(); + [[nodiscard]] bool atomicWake(MemoryAccessDesc* access); + [[nodiscard]] bool emitFence(); + [[nodiscard]] bool emitAtomicXchg(ValType type, Scalar::Type viewType); + [[nodiscard]] bool emitMemInit(); + [[nodiscard]] bool emitMemCopy(); + [[nodiscard]] bool memCopyCall(uint32_t dstMemIndex, uint32_t srcMemIndex); + void memCopyInlineM32(); + [[nodiscard]] bool emitTableCopy(); + [[nodiscard]] bool emitDataOrElemDrop(bool isData); + [[nodiscard]] bool emitMemFill(); + [[nodiscard]] bool memFillCall(uint32_t memoryIndex); + void memFillInlineM32(); + [[nodiscard]] bool emitTableInit(); + [[nodiscard]] bool emitTableFill(); + [[nodiscard]] bool emitMemDiscard(); + [[nodiscard]] bool emitTableGet(); + [[nodiscard]] bool emitTableGrow(); + [[nodiscard]] bool emitTableSet(); + [[nodiscard]] bool emitTableSize(); + + void emitTableBoundsCheck(uint32_t tableIndex, RegI32 index, RegPtr instance); + [[nodiscard]] bool emitTableGetAnyRef(uint32_t tableIndex); + [[nodiscard]] bool emitTableSetAnyRef(uint32_t tableIndex); + +#ifdef ENABLE_WASM_GC + [[nodiscard]] bool emitStructNew(); + [[nodiscard]] bool emitStructNewDefault(); + [[nodiscard]] bool emitStructGet(FieldWideningOp wideningOp); + [[nodiscard]] bool emitStructSet(); + [[nodiscard]] bool emitArrayNew(); + [[nodiscard]] bool emitArrayNewFixed(); + [[nodiscard]] bool emitArrayNewDefault(); + [[nodiscard]] bool emitArrayNewData(); + [[nodiscard]] bool emitArrayNewElem(); + [[nodiscard]] bool emitArrayInitData(); + [[nodiscard]] bool emitArrayInitElem(); + [[nodiscard]] bool emitArrayGet(FieldWideningOp wideningOp); + [[nodiscard]] bool emitArraySet(); + [[nodiscard]] bool emitArrayLen(); + [[nodiscard]] bool emitArrayCopy(); + [[nodiscard]] bool emitArrayFill(); + [[nodiscard]] bool emitRefI31(); + [[nodiscard]] bool emitI31Get(FieldWideningOp wideningOp); + [[nodiscard]] bool emitRefTest(bool nullable); + [[nodiscard]] bool emitRefCast(bool nullable); + [[nodiscard]] bool emitBrOnCastCommon(bool onSuccess, + uint32_t labelRelativeDepth, + const ResultType& labelType, + RefType sourceType, RefType destType); + [[nodiscard]] bool emitBrOnCast(bool onSuccess); + [[nodiscard]] bool emitAnyConvertExtern(); + [[nodiscard]] bool emitExternConvertAny(); + + // Utility classes/methods to add trap information related to + // null pointer dereferences/accesses. + struct NoNullCheck { + static void emitNullCheck(BaseCompiler* bc, RegRef rp) {} + static void emitTrapSite(BaseCompiler* bc, FaultingCodeOffset fco, + TrapMachineInsn tmi) {} + }; + struct SignalNullCheck { + static void emitNullCheck(BaseCompiler* bc, RegRef rp); + static void emitTrapSite(BaseCompiler* bc, FaultingCodeOffset fco, + TrapMachineInsn tmi); + }; + + // Load a pointer to the TypeDefInstanceData for a given type index + RegPtr loadTypeDefInstanceData(uint32_t typeIndex); + // Load a pointer to the SuperTypeVector for a given type index + RegPtr loadSuperTypeVector(uint32_t typeIndex); + + // Emits allocation code for a GC struct. The struct may have an out-of-line + // data area; if so, `isOutlineStruct` will be true and `outlineBase` will be + // allocated and must be freed. + template <bool ZeroFields> + bool emitStructAlloc(uint32_t typeIndex, RegRef* object, + bool* isOutlineStruct, RegPtr* outlineBase); + // Emits allocation code for a dynamically-sized GC array. + template <bool ZeroFields> + bool emitArrayAlloc(uint32_t typeIndex, RegRef object, RegI32 numElements, + uint32_t elemSize); + // Emits allocation code for a fixed-size GC array. + template <bool ZeroFields> + bool emitArrayAllocFixed(uint32_t typeIndex, RegRef object, + uint32_t numElements, uint32_t elemSize); + + template <typename NullCheckPolicy> + RegPtr emitGcArrayGetData(RegRef rp); + template <typename NullCheckPolicy> + RegI32 emitGcArrayGetNumElements(RegRef rp); + void emitGcArrayBoundsCheck(RegI32 index, RegI32 numElements); + template <typename T, typename NullCheckPolicy> + void emitGcGet(StorageType type, FieldWideningOp wideningOp, const T& src); + template <typename T, typename NullCheckPolicy> + void emitGcSetScalar(const T& dst, StorageType type, AnyReg value); + + BranchIfRefSubtypeRegisters allocRegistersForBranchIfRefSubtype( + RefType destType); + void freeRegistersForBranchIfRefSubtype( + const BranchIfRefSubtypeRegisters& regs); + + // Write `value` to wasm struct `object`, at `areaBase + areaOffset`. The + // caller must decide on the in- vs out-of-lineness before the call and set + // the latter two accordingly; this routine does not take that into account. + // The value in `object` is unmodified, but `areaBase` and `value` may get + // trashed. + template <typename NullCheckPolicy> + [[nodiscard]] bool emitGcStructSet(RegRef object, RegPtr areaBase, + uint32_t areaOffset, StorageType type, + AnyReg value, + PreBarrierKind preBarrierKind); + + [[nodiscard]] bool emitGcArraySet(RegRef object, RegPtr data, RegI32 index, + const ArrayType& array, AnyReg value, + PreBarrierKind preBarrierKind); +#endif // ENABLE_WASM_GC + +#ifdef ENABLE_WASM_SIMD + void emitVectorAndNot(); +# ifdef ENABLE_WASM_RELAXED_SIMD + void emitDotI8x16I7x16AddS(); +# endif + + void loadSplat(MemoryAccessDesc* access); + void loadZero(MemoryAccessDesc* access); + void loadExtend(MemoryAccessDesc* access, Scalar::Type viewType); + void loadLane(MemoryAccessDesc* access, uint32_t laneIndex); + void storeLane(MemoryAccessDesc* access, uint32_t laneIndex); + + [[nodiscard]] bool emitLoadSplat(Scalar::Type viewType); + [[nodiscard]] bool emitLoadZero(Scalar::Type viewType); + [[nodiscard]] bool emitLoadExtend(Scalar::Type viewType); + [[nodiscard]] bool emitLoadLane(uint32_t laneSize); + [[nodiscard]] bool emitStoreLane(uint32_t laneSize); + [[nodiscard]] bool emitVectorShuffle(); + [[nodiscard]] bool emitVectorLaneSelect(); +# if defined(JS_CODEGEN_X86) || defined(JS_CODEGEN_X64) + [[nodiscard]] bool emitVectorShiftRightI64x2(); +# endif +#endif + [[nodiscard]] bool emitCallBuiltinModuleFunc(); +}; + +} // namespace wasm +} // namespace js + +#endif // wasm_wasm_baseline_object_h |