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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /js/src/jit/arm/Trampoline-arm.cpp
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/jit/arm/Trampoline-arm.cpp')
-rw-r--r--js/src/jit/arm/Trampoline-arm.cpp757
1 files changed, 757 insertions, 0 deletions
diff --git a/js/src/jit/arm/Trampoline-arm.cpp b/js/src/jit/arm/Trampoline-arm.cpp
new file mode 100644
index 0000000000..f389b694a0
--- /dev/null
+++ b/js/src/jit/arm/Trampoline-arm.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * 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/. */
+
+#include "jit/arm/SharedICHelpers-arm.h"
+#include "jit/Bailouts.h"
+#include "jit/BaselineFrame.h"
+#include "jit/CalleeToken.h"
+#include "jit/JitFrames.h"
+#include "jit/JitRuntime.h"
+#include "jit/JitSpewer.h"
+#include "jit/PerfSpewer.h"
+#include "jit/VMFunctions.h"
+#include "vm/JitActivation.h" // js::jit::JitActivation
+#include "vm/JSContext.h"
+#include "vm/Realm.h"
+
+#include "jit/MacroAssembler-inl.h"
+
+using namespace js;
+using namespace js::jit;
+
+static const FloatRegisterSet NonVolatileFloatRegs = FloatRegisterSet(
+ (1ULL << FloatRegisters::d8) | (1ULL << FloatRegisters::d9) |
+ (1ULL << FloatRegisters::d10) | (1ULL << FloatRegisters::d11) |
+ (1ULL << FloatRegisters::d12) | (1ULL << FloatRegisters::d13) |
+ (1ULL << FloatRegisters::d14) | (1ULL << FloatRegisters::d15));
+
+static void GenerateReturn(MacroAssembler& masm, int returnCode) {
+ // Restore non-volatile floating point registers.
+ masm.transferMultipleByRuns(NonVolatileFloatRegs, IsLoad, StackPointer, IA);
+
+ // Get rid of padding word.
+ masm.addPtr(Imm32(sizeof(void*)), sp);
+
+ // Set up return value
+ masm.ma_mov(Imm32(returnCode), r0);
+
+ // Pop and return
+ masm.startDataTransferM(IsLoad, sp, IA, WriteBack);
+ masm.transferReg(r4);
+ masm.transferReg(r5);
+ masm.transferReg(r6);
+ masm.transferReg(r7);
+ masm.transferReg(r8);
+ masm.transferReg(r9);
+ masm.transferReg(r10);
+ masm.transferReg(r11);
+ // r12 isn't saved, so it shouldn't be restored.
+ masm.transferReg(pc);
+ masm.finishDataTransfer();
+ masm.flushBuffer();
+}
+
+struct EnterJITStack {
+ double d8;
+ double d9;
+ double d10;
+ double d11;
+ double d12;
+ double d13;
+ double d14;
+ double d15;
+
+ // Padding.
+ void* padding;
+
+ // Non-volatile registers.
+ void* r4;
+ void* r5;
+ void* r6;
+ void* r7;
+ void* r8;
+ void* r9;
+ void* r10;
+ void* r11;
+ // The abi does not expect r12 (ip) to be preserved
+ void* lr;
+
+ // Arguments.
+ // code == r0
+ // argc == r1
+ // argv == r2
+ // frame == r3
+ CalleeToken token;
+ JSObject* scopeChain;
+ size_t numStackValues;
+ Value* vp;
+};
+
+/*
+ * This method generates a trampoline for a c++ function with the following
+ * signature:
+ * void enter(void* code, int argc, Value* argv, InterpreterFrame* fp,
+ * CalleeToken calleeToken, JSObject* scopeChain, Value* vp)
+ * ...using standard EABI calling convention
+ */
+void JitRuntime::generateEnterJIT(JSContext* cx, MacroAssembler& masm) {
+ AutoCreatedBy acb(masm, "JitRuntime::generateEnterJIT");
+
+ enterJITOffset_ = startTrampolineCode(masm);
+
+ const Address slot_token(sp, offsetof(EnterJITStack, token));
+ const Address slot_vp(sp, offsetof(EnterJITStack, vp));
+
+ static_assert(OsrFrameReg == r3);
+
+ Assembler* aasm = &masm;
+
+ // Save non-volatile registers. These must be saved by the trampoline,
+ // rather than the JIT'd code, because they are scanned by the conservative
+ // scanner.
+ masm.startDataTransferM(IsStore, sp, DB, WriteBack);
+ masm.transferReg(r4); // [sp,0]
+ masm.transferReg(r5); // [sp,4]
+ masm.transferReg(r6); // [sp,8]
+ masm.transferReg(r7); // [sp,12]
+ masm.transferReg(r8); // [sp,16]
+ masm.transferReg(r9); // [sp,20]
+ masm.transferReg(r10); // [sp,24]
+ masm.transferReg(r11); // [sp,28]
+ // The abi does not expect r12 (ip) to be preserved
+ masm.transferReg(lr); // [sp,32]
+ // The 5th argument is located at [sp, 36]
+ masm.finishDataTransfer();
+
+ // Add padding word.
+ masm.subPtr(Imm32(sizeof(void*)), sp);
+
+ // Push the float registers.
+ masm.transferMultipleByRuns(NonVolatileFloatRegs, IsStore, sp, DB);
+
+ // Load calleeToken into r9.
+ masm.loadPtr(slot_token, r9);
+
+ // Save stack pointer.
+ masm.movePtr(sp, r11);
+
+ // Load the number of actual arguments into r10.
+ masm.loadPtr(slot_vp, r10);
+ masm.unboxInt32(Address(r10, 0), r10);
+
+ {
+ Label noNewTarget;
+ masm.branchTest32(Assembler::Zero, r9,
+ Imm32(CalleeToken_FunctionConstructing), &noNewTarget);
+
+ masm.add32(Imm32(1), r1);
+
+ masm.bind(&noNewTarget);
+ }
+
+ // Guarantee stack alignment of Jit frames.
+ //
+ // This code moves the stack pointer to the location where it should be when
+ // we enter the Jit frame. It moves the stack pointer such that we have
+ // enough space reserved for pushing the arguments, and the JitFrameLayout.
+ // The stack pointer is also aligned on the alignment expected by the Jit
+ // frames.
+ //
+ // At the end the register r4, is a pointer to the stack where the first
+ // argument is expected by the Jit frame.
+ //
+ aasm->as_sub(r4, sp, O2RegImmShift(r1, LSL, 3)); // r4 = sp - argc*8
+ aasm->as_bic(r4, r4, Imm8(JitStackAlignment - 1));
+ // r4 is now the aligned on the bottom of the list of arguments.
+ static_assert(
+ sizeof(JitFrameLayout) % JitStackAlignment == 0,
+ "No need to consider the JitFrameLayout for aligning the stack");
+ // sp' = ~(JitStackAlignment - 1) & (sp - argc * sizeof(Value))
+ masm.movePtr(r4, sp);
+
+ // Get a copy of the number of args to use as a decrement counter, also set
+ // the zero condition code.
+ aasm->as_mov(r5, O2Reg(r1), SetCC);
+
+ // Loop over arguments, copying them from an unknown buffer onto the Ion
+ // stack so they can be accessed from JIT'ed code.
+ {
+ Label header, footer;
+ // If there aren't any arguments, don't do anything.
+ aasm->as_b(&footer, Assembler::Zero);
+ // Get the top of the loop.
+ masm.bind(&header);
+ aasm->as_sub(r5, r5, Imm8(1), SetCC);
+ // We could be more awesome, and unroll this, using a loadm
+ // (particularly since the offset is effectively 0) but that seems more
+ // error prone, and complex.
+ // BIG FAT WARNING: this loads both r6 and r7.
+ aasm->as_extdtr(IsLoad, 64, true, PostIndex, r6,
+ EDtrAddr(r2, EDtrOffImm(8)));
+ aasm->as_extdtr(IsStore, 64, true, PostIndex, r6,
+ EDtrAddr(r4, EDtrOffImm(8)));
+ aasm->as_b(&header, Assembler::NonZero);
+ masm.bind(&footer);
+ }
+
+ // Push the callee token.
+ masm.push(r9);
+
+ // Push the frame descriptor.
+ masm.pushFrameDescriptorForJitCall(FrameType::CppToJSJit, r10, r10);
+
+ Label returnLabel;
+ {
+ // Handle Interpreter -> Baseline OSR.
+ AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+ MOZ_ASSERT(!regs.has(r11));
+ regs.take(OsrFrameReg);
+ regs.take(r0); // jitcode
+ MOZ_ASSERT(!regs.has(ReturnReg), "ReturnReg matches r0");
+
+ const Address slot_numStackValues(r11,
+ offsetof(EnterJITStack, numStackValues));
+
+ Label notOsr;
+ masm.branchTestPtr(Assembler::Zero, OsrFrameReg, OsrFrameReg, &notOsr);
+
+ Register scratch = regs.takeAny();
+
+ Register numStackValues = regs.takeAny();
+ masm.load32(slot_numStackValues, numStackValues);
+
+ // Write return address. On ARM, CodeLabel is only used for tableswitch,
+ // so we can't use it here to get the return address. Instead, we use pc
+ // + a fixed offset to a jump to returnLabel. The pc register holds pc +
+ // 8, so we add the size of 2 instructions to skip the instructions
+ // emitted by push and jump(&skipJump).
+ {
+ AutoForbidPoolsAndNops afp(&masm, 5);
+ Label skipJump;
+ masm.mov(pc, scratch);
+ masm.addPtr(Imm32(2 * sizeof(uint32_t)), scratch);
+ masm.push(scratch);
+ masm.jump(&skipJump);
+ masm.jump(&returnLabel);
+ masm.bind(&skipJump);
+ }
+
+ // Frame prologue.
+ masm.push(FramePointer);
+ masm.mov(sp, FramePointer);
+
+ // Reserve frame.
+ masm.subPtr(Imm32(BaselineFrame::Size()), sp);
+
+ Register framePtrScratch = regs.takeAny();
+ masm.touchFrameValues(numStackValues, scratch, framePtrScratch);
+ masm.mov(sp, framePtrScratch);
+
+ // Reserve space for locals and stack values.
+ masm.ma_lsl(Imm32(3), numStackValues, scratch);
+ masm.ma_sub(sp, scratch, sp);
+
+ // Enter exit frame.
+ masm.pushFrameDescriptor(FrameType::BaselineJS);
+ masm.push(Imm32(0)); // Fake return address.
+ masm.push(FramePointer);
+ // No GC things to mark on the stack, push a bare token.
+ masm.loadJSContext(scratch);
+ masm.enterFakeExitFrame(scratch, scratch, ExitFrameType::Bare);
+
+ masm.push(r0); // jitcode
+
+ using Fn = bool (*)(BaselineFrame* frame, InterpreterFrame* interpFrame,
+ uint32_t numStackValues);
+ masm.setupUnalignedABICall(scratch);
+ masm.passABIArg(framePtrScratch); // BaselineFrame
+ masm.passABIArg(OsrFrameReg); // InterpreterFrame
+ masm.passABIArg(numStackValues);
+ masm.callWithABI<Fn, jit::InitBaselineFrameForOsr>(
+ ABIType::General, CheckUnsafeCallWithABI::DontCheckHasExitFrame);
+
+ Register jitcode = regs.takeAny();
+ masm.pop(jitcode);
+
+ MOZ_ASSERT(jitcode != ReturnReg);
+
+ Label error;
+ masm.addPtr(Imm32(ExitFrameLayout::SizeWithFooter()), sp);
+ masm.branchIfFalseBool(ReturnReg, &error);
+
+ // If OSR-ing, then emit instrumentation for setting lastProfilerFrame
+ // if profiler instrumentation is enabled.
+ {
+ Label skipProfilingInstrumentation;
+ AbsoluteAddress addressOfEnabled(
+ cx->runtime()->geckoProfiler().addressOfEnabled());
+ masm.branch32(Assembler::Equal, addressOfEnabled, Imm32(0),
+ &skipProfilingInstrumentation);
+ masm.profilerEnterFrame(FramePointer, scratch);
+ masm.bind(&skipProfilingInstrumentation);
+ }
+
+ masm.jump(jitcode);
+
+ // OOM: frame epilogue, load error value, discard return address and return.
+ masm.bind(&error);
+ masm.mov(FramePointer, sp);
+ masm.pop(FramePointer);
+ masm.addPtr(Imm32(sizeof(uintptr_t)), sp); // Return address.
+ masm.moveValue(MagicValue(JS_ION_ERROR), JSReturnOperand);
+ masm.jump(&returnLabel);
+
+ masm.bind(&notOsr);
+ // Load the scope chain in R1.
+ MOZ_ASSERT(R1.scratchReg() != r0);
+ masm.loadPtr(Address(r11, offsetof(EnterJITStack, scopeChain)),
+ R1.scratchReg());
+ }
+
+ // The callee will push the return address and frame pointer on the stack,
+ // thus we check that the stack would be aligned once the call is complete.
+ masm.assertStackAlignment(JitStackAlignment, 2 * sizeof(uintptr_t));
+
+ // Call the function.
+ masm.callJitNoProfiler(r0);
+
+ // Interpreter -> Baseline OSR will return here.
+ masm.bind(&returnLabel);
+
+ // Discard arguments and padding. Set sp to the address of the EnterJITStack
+ // on the stack.
+ masm.mov(r11, sp);
+
+ // Store the returned value into the slot_vp
+ masm.loadPtr(slot_vp, r5);
+ masm.storeValue(JSReturnOperand, Address(r5, 0));
+
+ // Restore non-volatile registers and return.
+ GenerateReturn(masm, true);
+}
+
+// static
+mozilla::Maybe<::JS::ProfilingFrameIterator::RegisterState>
+JitRuntime::getCppEntryRegisters(JitFrameLayout* frameStackAddress) {
+ // Not supported, or not implemented yet.
+ // TODO: Implement along with the corresponding stack-walker changes, in
+ // coordination with the Gecko Profiler, see bug 1635987 and follow-ups.
+ return mozilla::Nothing{};
+}
+
+void JitRuntime::generateInvalidator(MacroAssembler& masm, Label* bailoutTail) {
+ // See large comment in x86's JitRuntime::generateInvalidator.
+
+ AutoCreatedBy acb(masm, "JitRuntime::generateInvalidator");
+
+ invalidatorOffset_ = startTrampolineCode(masm);
+
+ // At this point, one of two things has happened:
+ // 1) Execution has just returned from C code, which left the stack aligned
+ // 2) Execution has just returned from Ion code, which left the stack
+ // unaligned. The old return address should not matter, but we still want the
+ // stack to be aligned, and there is no good reason to automatically align it
+ // with a call to setupUnalignedABICall.
+ masm.as_bic(sp, sp, Imm8(7));
+ masm.startDataTransferM(IsStore, sp, DB, WriteBack);
+ // We don't have to push everything, but this is likely easier.
+ // Setting regs_.
+ for (uint32_t i = 0; i < Registers::Total; i++) {
+ masm.transferReg(Register::FromCode(i));
+ }
+ masm.finishDataTransfer();
+
+ // Since our datastructures for stack inspection are compile-time fixed,
+ // if there are only 16 double registers, then we need to reserve
+ // space on the stack for the missing 16.
+ if (FloatRegisters::ActualTotalPhys() != FloatRegisters::TotalPhys) {
+ ScratchRegisterScope scratch(masm);
+ int missingRegs =
+ FloatRegisters::TotalPhys - FloatRegisters::ActualTotalPhys();
+ masm.ma_sub(Imm32(missingRegs * sizeof(double)), sp, scratch);
+ }
+
+ masm.startFloatTransferM(IsStore, sp, DB, WriteBack);
+ for (uint32_t i = 0; i < FloatRegisters::ActualTotalPhys(); i++) {
+ masm.transferFloatReg(FloatRegister(i, FloatRegister::Double));
+ }
+ masm.finishFloatTransfer();
+
+ masm.ma_mov(sp, r0);
+ // Reserve 8 bytes for the outparam to ensure alignment for
+ // setupAlignedABICall.
+ masm.reserveStack(sizeof(void*) * 2);
+ masm.mov(sp, r1);
+ using Fn = bool (*)(InvalidationBailoutStack* sp, BaselineBailoutInfo** info);
+ masm.setupAlignedABICall();
+ masm.passABIArg(r0);
+ masm.passABIArg(r1);
+ masm.callWithABI<Fn, InvalidationBailout>(
+ ABIType::General, CheckUnsafeCallWithABI::DontCheckOther);
+
+ masm.pop(r2); // Get bailoutInfo outparam.
+
+ // Pop the machine state and the dead frame.
+ masm.moveToStackPtr(FramePointer);
+
+ // Jump to shared bailout tail. The BailoutInfo pointer has to be in r2.
+ masm.jump(bailoutTail);
+}
+
+void JitRuntime::generateArgumentsRectifier(MacroAssembler& masm,
+ ArgumentsRectifierKind kind) {
+ AutoCreatedBy acb(masm, "JitRuntime::generateArgumentsRectifier");
+
+ switch (kind) {
+ case ArgumentsRectifierKind::Normal:
+ argumentsRectifierOffset_ = startTrampolineCode(masm);
+ break;
+ case ArgumentsRectifierKind::TrialInlining:
+ trialInliningArgumentsRectifierOffset_ = startTrampolineCode(masm);
+ break;
+ }
+ masm.pushReturnAddress();
+
+ // Frame prologue.
+ //
+ // NOTE: if this changes, fix the Baseline bailout code too!
+ // See BaselineStackBuilder::calculatePrevFramePtr and
+ // BaselineStackBuilder::buildRectifierFrame (in BaselineBailouts.cpp).
+ masm.push(FramePointer);
+ masm.mov(StackPointer, FramePointer);
+
+ static_assert(JitStackAlignment == sizeof(Value));
+
+ // Copy number of actual arguments into r0 and r8.
+ masm.loadNumActualArgs(FramePointer, r0);
+ masm.mov(r0, r8);
+
+ // Load the number of |undefined|s to push into r6.
+ masm.loadPtr(
+ Address(FramePointer, RectifierFrameLayout::offsetOfCalleeToken()), r1);
+ {
+ ScratchRegisterScope scratch(masm);
+ masm.ma_and(Imm32(CalleeTokenMask), r1, r6, scratch);
+ }
+ masm.loadFunctionArgCount(r6, r6);
+
+ masm.ma_sub(r6, r8, r2);
+
+ // Get the topmost argument.
+ {
+ ScratchRegisterScope scratch(masm);
+ masm.ma_alu(sp, lsl(r8, 3), r3, OpAdd); // r3 <- sp + nargs * 8
+ masm.ma_add(r3, Imm32(sizeof(RectifierFrameLayout)), r3, scratch);
+ }
+
+ {
+ Label notConstructing;
+
+ masm.branchTest32(Assembler::Zero, r1,
+ Imm32(CalleeToken_FunctionConstructing),
+ &notConstructing);
+
+ // Add sizeof(Value) to overcome |this|
+ masm.as_extdtr(IsLoad, 64, true, Offset, r4, EDtrAddr(r3, EDtrOffImm(8)));
+ masm.as_extdtr(IsStore, 64, true, PreIndex, r4,
+ EDtrAddr(sp, EDtrOffImm(-8)));
+
+ masm.bind(&notConstructing);
+ }
+
+ // Push undefined.
+ masm.moveValue(UndefinedValue(), ValueOperand(r5, r4));
+ {
+ Label undefLoopTop;
+ masm.bind(&undefLoopTop);
+ masm.as_extdtr(IsStore, 64, true, PreIndex, r4,
+ EDtrAddr(sp, EDtrOffImm(-8)));
+ masm.as_sub(r2, r2, Imm8(1), SetCC);
+
+ masm.ma_b(&undefLoopTop, Assembler::NonZero);
+ }
+
+ // Push arguments, |nargs| + 1 times (to include |this|).
+ {
+ Label copyLoopTop;
+ masm.bind(&copyLoopTop);
+ masm.as_extdtr(IsLoad, 64, true, PostIndex, r4,
+ EDtrAddr(r3, EDtrOffImm(-8)));
+ masm.as_extdtr(IsStore, 64, true, PreIndex, r4,
+ EDtrAddr(sp, EDtrOffImm(-8)));
+
+ masm.as_sub(r8, r8, Imm8(1), SetCC);
+ masm.ma_b(&copyLoopTop, Assembler::NotSigned);
+ }
+
+ // Construct JitFrameLayout.
+ masm.ma_push(r1); // callee token
+ masm.pushFrameDescriptorForJitCall(FrameType::Rectifier, r0, r0);
+
+ // Call the target function.
+ masm.andPtr(Imm32(CalleeTokenMask), r1);
+ switch (kind) {
+ case ArgumentsRectifierKind::Normal:
+ masm.loadJitCodeRaw(r1, r3);
+ argumentsRectifierReturnOffset_ = masm.callJitNoProfiler(r3);
+ break;
+ case ArgumentsRectifierKind::TrialInlining:
+ Label noBaselineScript, done;
+ masm.loadBaselineJitCodeRaw(r1, r3, &noBaselineScript);
+ masm.callJitNoProfiler(r3);
+ masm.jump(&done);
+
+ // See BaselineCacheIRCompiler::emitCallInlinedFunction.
+ masm.bind(&noBaselineScript);
+ masm.loadJitCodeRaw(r1, r3);
+ masm.callJitNoProfiler(r3);
+ masm.bind(&done);
+ break;
+ }
+
+ masm.mov(FramePointer, StackPointer);
+ masm.pop(FramePointer);
+ masm.ret();
+}
+
+static void PushBailoutFrame(MacroAssembler& masm, Register spArg) {
+#ifdef ENABLE_WASM_SIMD
+# error "Needs more careful logic if SIMD is enabled"
+#endif
+
+ // STEP 1a: Save our register sets to the stack so Bailout() can read
+ // everything.
+ // sp % 8 == 0
+
+ masm.startDataTransferM(IsStore, sp, DB, WriteBack);
+ // We don't have to push everything, but this is likely easier.
+ // Setting regs_.
+ for (uint32_t i = 0; i < Registers::Total; i++) {
+ masm.transferReg(Register::FromCode(i));
+ }
+ masm.finishDataTransfer();
+
+ ScratchRegisterScope scratch(masm);
+
+ // Since our datastructures for stack inspection are compile-time fixed,
+ // if there are only 16 double registers, then we need to reserve
+ // space on the stack for the missing 16.
+ if (FloatRegisters::ActualTotalPhys() != FloatRegisters::TotalPhys) {
+ int missingRegs =
+ FloatRegisters::TotalPhys - FloatRegisters::ActualTotalPhys();
+ masm.ma_sub(Imm32(missingRegs * sizeof(double)), sp, scratch);
+ }
+ masm.startFloatTransferM(IsStore, sp, DB, WriteBack);
+ for (uint32_t i = 0; i < FloatRegisters::ActualTotalPhys(); i++) {
+ masm.transferFloatReg(FloatRegister(i, FloatRegister::Double));
+ }
+ masm.finishFloatTransfer();
+
+ // The current stack pointer is the first argument to jit::Bailout.
+ masm.ma_mov(sp, spArg);
+}
+
+static void GenerateBailoutThunk(MacroAssembler& masm, Label* bailoutTail) {
+ PushBailoutFrame(masm, r0);
+
+ // Make space for Bailout's bailoutInfo outparam.
+ masm.reserveStack(sizeof(void*));
+ masm.mov(sp, r1);
+ using Fn = bool (*)(BailoutStack* sp, BaselineBailoutInfo** info);
+ masm.setupAlignedABICall();
+
+ masm.passABIArg(r0);
+ masm.passABIArg(r1);
+
+ masm.callWithABI<Fn, Bailout>(ABIType::General,
+ CheckUnsafeCallWithABI::DontCheckOther);
+ masm.pop(r2); // Get the bailoutInfo outparam.
+
+ // Remove both the bailout frame and the topmost Ion frame's stack.
+ masm.moveToStackPtr(FramePointer);
+
+ // Jump to shared bailout tail. The BailoutInfo pointer has to be in r2.
+ masm.jump(bailoutTail);
+}
+
+void JitRuntime::generateBailoutHandler(MacroAssembler& masm,
+ Label* bailoutTail) {
+ AutoCreatedBy acb(masm, "JitRuntime::generateBailoutHandler");
+
+ bailoutHandlerOffset_ = startTrampolineCode(masm);
+
+ GenerateBailoutThunk(masm, bailoutTail);
+}
+
+bool JitRuntime::generateVMWrapper(JSContext* cx, MacroAssembler& masm,
+ VMFunctionId id, const VMFunctionData& f,
+ DynFn nativeFun, uint32_t* wrapperOffset) {
+ AutoCreatedBy acb(masm, "JitRuntime::generateVMWrapper");
+
+ *wrapperOffset = startTrampolineCode(masm);
+
+ AllocatableGeneralRegisterSet regs(Register::Codes::WrapperMask);
+
+ static_assert(
+ (Register::Codes::VolatileMask & ~Register::Codes::WrapperMask) == 0,
+ "Wrapper register set must be a superset of Volatile register set.");
+
+ // The context is the first argument; r0 is the first argument register.
+ Register cxreg = r0;
+ regs.take(cxreg);
+
+ // On link-register platforms, it is the responsibility of the VM *callee* to
+ // push the return address, while the caller must ensure that the address
+ // is stored in lr on entry. This allows the VM wrapper to work with both
+ // direct calls and tail calls.
+ masm.pushReturnAddress();
+
+ // Push the frame pointer to finish the exit frame, then link it up.
+ masm.Push(FramePointer);
+ masm.moveStackPtrTo(FramePointer);
+ masm.loadJSContext(cxreg);
+ masm.enterExitFrame(cxreg, regs.getAny(), id);
+
+ // Reserve space for the outparameter.
+ masm.reserveVMFunctionOutParamSpace(f);
+
+ masm.setupUnalignedABICallDontSaveRestoreSP();
+ masm.passABIArg(cxreg);
+
+ size_t argDisp = ExitFrameLayout::Size();
+
+ // Copy any arguments.
+ for (uint32_t explicitArg = 0; explicitArg < f.explicitArgs; explicitArg++) {
+ switch (f.argProperties(explicitArg)) {
+ case VMFunctionData::WordByValue:
+ masm.passABIArg(MoveOperand(FramePointer, argDisp), ABIType::General);
+ argDisp += sizeof(void*);
+ break;
+ case VMFunctionData::DoubleByValue:
+ // Values should be passed by reference, not by value, so we assert
+ // that the argument is a double-precision float.
+ MOZ_ASSERT(f.argPassedInFloatReg(explicitArg));
+ masm.passABIArg(MoveOperand(FramePointer, argDisp), ABIType::Float64);
+ argDisp += sizeof(double);
+ break;
+ case VMFunctionData::WordByRef:
+ masm.passABIArg(MoveOperand(FramePointer, argDisp,
+ MoveOperand::Kind::EffectiveAddress),
+ ABIType::General);
+ argDisp += sizeof(void*);
+ break;
+ case VMFunctionData::DoubleByRef:
+ masm.passABIArg(MoveOperand(FramePointer, argDisp,
+ MoveOperand::Kind::EffectiveAddress),
+ ABIType::General);
+ argDisp += 2 * sizeof(void*);
+ break;
+ }
+ }
+
+ // Copy the implicit outparam, if any.
+ const int32_t outParamOffset =
+ -int32_t(ExitFooterFrame::Size()) - f.sizeOfOutParamStackSlot();
+ if (f.outParam != Type_Void) {
+ masm.passABIArg(MoveOperand(FramePointer, outParamOffset,
+ MoveOperand::Kind::EffectiveAddress),
+ ABIType::General);
+ }
+
+ masm.callWithABI(nativeFun, ABIType::General,
+ CheckUnsafeCallWithABI::DontCheckHasExitFrame);
+
+ // Test for failure.
+ switch (f.failType()) {
+ case Type_Cell:
+ masm.branchTestPtr(Assembler::Zero, r0, r0, masm.failureLabel());
+ break;
+ case Type_Bool:
+ masm.branchIfFalseBool(r0, masm.failureLabel());
+ break;
+ case Type_Void:
+ break;
+ default:
+ MOZ_CRASH("unknown failure kind");
+ }
+
+ // Load the outparam.
+ masm.loadVMFunctionOutParam(f, Address(FramePointer, outParamOffset));
+
+ // Until C++ code is instrumented against Spectre, prevent speculative
+ // execution from returning any private data.
+ if (f.returnsData() && JitOptions.spectreJitToCxxCalls) {
+ masm.speculationBarrier();
+ }
+
+ // Pop frame and restore frame pointer.
+ masm.moveToStackPtr(FramePointer);
+ masm.pop(FramePointer);
+
+ // Return. Subtract sizeof(void*) for the frame pointer.
+ masm.retn(Imm32(sizeof(ExitFrameLayout) - sizeof(void*) +
+ f.explicitStackSlots() * sizeof(void*) +
+ f.extraValuesToPop * sizeof(Value)));
+
+ return true;
+}
+
+uint32_t JitRuntime::generatePreBarrier(JSContext* cx, MacroAssembler& masm,
+ MIRType type) {
+ AutoCreatedBy acb(masm, "JitRuntime::generatePreBarrier");
+
+ uint32_t offset = startTrampolineCode(masm);
+
+ masm.pushReturnAddress();
+
+ static_assert(PreBarrierReg == r1);
+ Register temp1 = r2;
+ Register temp2 = r3;
+ Register temp3 = r4;
+ masm.push(temp1);
+ masm.push(temp2);
+ masm.push(temp3);
+
+ Label noBarrier;
+ masm.emitPreBarrierFastPath(cx->runtime(), type, temp1, temp2, temp3,
+ &noBarrier);
+
+ // Call into C++ to mark this GC thing.
+ masm.pop(temp3);
+ masm.pop(temp2);
+ masm.pop(temp1);
+
+ LiveRegisterSet save;
+ save.set() =
+ RegisterSet(GeneralRegisterSet(Registers::VolatileMask),
+ FloatRegisterSet(FloatRegisters::VolatileDoubleMask));
+ masm.PushRegsInMask(save);
+
+ masm.movePtr(ImmPtr(cx->runtime()), r0);
+
+ masm.setupUnalignedABICall(r2);
+ masm.passABIArg(r0);
+ masm.passABIArg(r1);
+ masm.callWithABI(JitPreWriteBarrier(type));
+ masm.PopRegsInMask(save);
+ masm.ret();
+
+ masm.bind(&noBarrier);
+ masm.pop(temp3);
+ masm.pop(temp2);
+ masm.pop(temp1);
+ masm.ret();
+
+ return offset;
+}
+
+void JitRuntime::generateBailoutTailStub(MacroAssembler& masm,
+ Label* bailoutTail) {
+ AutoCreatedBy acb(masm, "JitRuntime::generateBailoutTailStub");
+
+ masm.bind(bailoutTail);
+ masm.generateBailoutTail(r1, r2);
+}