1 files changed, 265 insertions, 0 deletions
diff --git a/js/src/jit/mips32/Assembler-mips32.h b/js/src/jit/mips32/Assembler-mips32.h
new file mode 100644
index 0000000000..496c382590
--- /dev/null
+++ b/js/src/jit/mips32/Assembler-mips32.h
@@ -0,0 +1,265 @@
+/* -*- 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/. */
+
+#ifndef jit_mips32_Assembler_mips32_h
+#define jit_mips32_Assembler_mips32_h
+
+#include <iterator>
+
+#include "jit/mips-shared/Assembler-mips-shared.h"
+
+#include "jit/mips32/Architecture-mips32.h"
+
+namespace js {
+namespace jit {
+
+static constexpr Register CallTempReg4 = t4;
+static constexpr Register CallTempReg5 = t5;
+
+static constexpr Register CallTempNonArgRegs[] = {t0, t1, t2, t3, t4};
+static const uint32_t NumCallTempNonArgRegs = std::size(CallTempNonArgRegs);
+
+class ABIArgGenerator {
+  unsigned usedArgSlots_;
+  unsigned firstArgFloatSize_;
+  // Note: This is not compliant with the system ABI.  The Lowering phase
+  // expects to lower an MWasmParameter to only one register.
+  bool useGPRForFloats_;
+  ABIArg current_;
+
+ public:
+  ABIArgGenerator();
+  ABIArg next(MIRType argType);
+  ABIArg& current() { return current_; }
+
+  void enforceO32ABI() { useGPRForFloats_ = true; }
+
+  uint32_t stackBytesConsumedSoFar() const {
+    if (usedArgSlots_ <= 4) {
+      return ShadowStackSpace;
+    }
+
+    return usedArgSlots_ * sizeof(intptr_t);
+  }
+
+  void increaseStackOffset(uint32_t bytes) { MOZ_CRASH("NYI"); }
+};
+
+// These registers may be volatile or nonvolatile.
+static constexpr Register ABINonArgReg0 = t0;
+static constexpr Register ABINonArgReg1 = t1;
+static constexpr Register ABINonArgReg2 = t2;
+static constexpr Register ABINonArgReg3 = t3;
+
+// This register may be volatile or nonvolatile. Avoid f18 which is the
+// ScratchDoubleReg.
+static constexpr FloatRegister ABINonArgDoubleReg{FloatRegisters::f16,
+                                                  FloatRegister::Double};
+
+// These registers may be volatile or nonvolatile.
+// Note: these three registers are all guaranteed to be different
+static constexpr Register ABINonArgReturnReg0 = t0;
+static constexpr Register ABINonArgReturnReg1 = t1;
+static constexpr Register ABINonVolatileReg = s0;
+
+// This register is guaranteed to be clobberable during the prologue and
+// epilogue of an ABI call which must preserve both ABI argument, return
+// and non-volatile registers.
+static constexpr Register ABINonArgReturnVolatileReg = t0;
+
+// TLS pointer argument register for WebAssembly functions. This must not alias
+// any other register used for passing function arguments or return values.
+// Preserved by WebAssembly functions.
+static constexpr Register InstanceReg = s5;
+
+// Registers used for asm.js/wasm table calls. These registers must be disjoint
+// from the ABI argument registers, InstanceReg and each other.
+static constexpr Register WasmTableCallScratchReg0 = ABINonArgReg0;
+static constexpr Register WasmTableCallScratchReg1 = ABINonArgReg1;
+static constexpr Register WasmTableCallSigReg = ABINonArgReg2;
+static constexpr Register WasmTableCallIndexReg = ABINonArgReg3;
+
+// Registers used for ref calls.
+static constexpr Register WasmCallRefCallScratchReg0 = ABINonArgReg0;
+static constexpr Register WasmCallRefCallScratchReg1 = ABINonArgReg1;
+static constexpr Register WasmCallRefReg = ABINonArgReg3;
+
+// Register used as a scratch along the return path in the fast js -> wasm stub
+// code. This must not overlap ReturnReg, JSReturnOperand, or InstanceReg.
+// It must be a volatile register.
+static constexpr Register WasmJitEntryReturnScratch = t1;
+
+static constexpr Register InterpreterPCReg = t5;
+
+static constexpr Register JSReturnReg_Type = a3;
+static constexpr Register JSReturnReg_Data = a2;
+static constexpr Register64 ReturnReg64(v1, v0);
+static constexpr FloatRegister ReturnFloat32Reg = {FloatRegisters::f0,
+                                                   FloatRegister::Single};
+static constexpr FloatRegister ReturnDoubleReg = {FloatRegisters::f0,
+                                                  FloatRegister::Double};
+static constexpr FloatRegister ScratchFloat32Reg = {FloatRegisters::f18,
+                                                    FloatRegister::Single};
+static constexpr FloatRegister ScratchDoubleReg = {FloatRegisters::f18,
+                                                   FloatRegister::Double};
+
+struct ScratchFloat32Scope : public AutoFloatRegisterScope {
+  explicit ScratchFloat32Scope(MacroAssembler& masm)
+      : AutoFloatRegisterScope(masm, ScratchFloat32Reg) {}
+};
+
+struct ScratchDoubleScope : public AutoFloatRegisterScope {
+  explicit ScratchDoubleScope(MacroAssembler& masm)
+      : AutoFloatRegisterScope(masm, ScratchDoubleReg) {}
+};
+
+static constexpr FloatRegister f0 = {FloatRegisters::f0, FloatRegister::Double};
+static constexpr FloatRegister f2 = {FloatRegisters::f2, FloatRegister::Double};
+static constexpr FloatRegister f4 = {FloatRegisters::f4, FloatRegister::Double};
+static constexpr FloatRegister f6 = {FloatRegisters::f6, FloatRegister::Double};
+static constexpr FloatRegister f8 = {FloatRegisters::f8, FloatRegister::Double};
+static constexpr FloatRegister f10 = {FloatRegisters::f10,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f12 = {FloatRegisters::f12,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f14 = {FloatRegisters::f14,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f16 = {FloatRegisters::f16,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f18 = {FloatRegisters::f18,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f20 = {FloatRegisters::f20,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f22 = {FloatRegisters::f22,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f24 = {FloatRegisters::f24,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f26 = {FloatRegisters::f26,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f28 = {FloatRegisters::f28,
+                                      FloatRegister::Double};
+static constexpr FloatRegister f30 = {FloatRegisters::f30,
+                                      FloatRegister::Double};
+
+// MIPS CPUs can only load multibyte data that is "naturally"
+// four-byte-aligned, sp register should be eight-byte-aligned.
+static constexpr uint32_t ABIStackAlignment = 8;
+static constexpr uint32_t JitStackAlignment = 8;
+
+static constexpr uint32_t JitStackValueAlignment =
+    JitStackAlignment / sizeof(Value);
+static_assert(JitStackAlignment % sizeof(Value) == 0 &&
+                  JitStackValueAlignment >= 1,
+              "Stack alignment should be a non-zero multiple of sizeof(Value)");
+
+// TODO this is just a filler to prevent a build failure. The MIPS SIMD
+// alignment requirements still need to be explored.
+// TODO Copy the static_asserts from x64/x86 assembler files.
+static constexpr uint32_t SimdMemoryAlignment = 8;
+static constexpr uint32_t WasmStackAlignment = SimdMemoryAlignment;
+static const uint32_t WasmTrapInstructionLength = 4;
+
+// See comments in wasm::GenerateFunctionPrologue.  The difference between these
+// is the size of the largest callable prologue on the platform.
+static constexpr uint32_t WasmCheckedCallEntryOffset = 0u;
+
+static constexpr Scale ScalePointer = TimesFour;
+
+class Assembler : public AssemblerMIPSShared {
+ public:
+  Assembler() : AssemblerMIPSShared() {}
+
+  static Condition UnsignedCondition(Condition cond);
+  static Condition ConditionWithoutEqual(Condition cond);
+
+  static uintptr_t GetPointer(uint8_t*);
+
+ protected:
+  // This is used to access the odd register form the pair of single
+  // precision registers that make one double register.
+  FloatRegister getOddPair(FloatRegister reg) {
+    MOZ_ASSERT(reg.isDouble());
+    MOZ_ASSERT(reg.id() % 2 == 0);
+    FloatRegister odd(reg.id() | 1, FloatRegister::Single);
+    return odd;
+  }
+
+ public:
+  using AssemblerMIPSShared::bind;
+
+  static void Bind(uint8_t* rawCode, const CodeLabel& label);
+
+  void processCodeLabels(uint8_t* rawCode);
+
+  static void TraceJumpRelocations(JSTracer* trc, JitCode* code,
+                                   CompactBufferReader& reader);
+  static void TraceDataRelocations(JSTracer* trc, JitCode* code,
+                                   CompactBufferReader& reader);
+
+  void bind(InstImm* inst, uintptr_t branch, uintptr_t target);
+
+  // Copy the assembly code to the given buffer, and perform any pending
+  // relocations relying on the target address.
+  void executableCopy(uint8_t* buffer);
+
+  static uint32_t PatchWrite_NearCallSize();
+
+  static uint32_t ExtractLuiOriValue(Instruction* inst0, Instruction* inst1);
+  static void WriteLuiOriInstructions(Instruction* inst, Instruction* inst1,
+                                      Register reg, uint32_t value);
+
+  static void PatchWrite_NearCall(CodeLocationLabel start,
+                                  CodeLocationLabel toCall);
+  static void PatchDataWithValueCheck(CodeLocationLabel label, ImmPtr newValue,
+                                      ImmPtr expectedValue);
+  static void PatchDataWithValueCheck(CodeLocationLabel label,
+                                      PatchedImmPtr newValue,
+                                      PatchedImmPtr expectedValue);
+
+  static uint32_t ExtractInstructionImmediate(uint8_t* code);
+
+  static void ToggleCall(CodeLocationLabel inst_, bool enabled);
+};  // Assembler
+
+static const uint32_t NumIntArgRegs = 4;
+
+static inline bool GetIntArgReg(uint32_t usedArgSlots, Register* out) {
+  if (usedArgSlots < NumIntArgRegs) {
+    *out = Register::FromCode(a0.code() + usedArgSlots);
+    return true;
+  }
+  return false;
+}
+
+// Get a register in which we plan to put a quantity that will be used as an
+// integer argument. This differs from GetIntArgReg in that if we have no more
+// actual argument registers to use we will fall back on using whatever
+// CallTempReg* don't overlap the argument registers, and only fail once those
+// run out too.
+static inline bool GetTempRegForIntArg(uint32_t usedIntArgs,
+                                       uint32_t usedFloatArgs, Register* out) {
+  // NOTE: We can't properly determine which regs are used if there are
+  // float arguments. If this is needed, we will have to guess.
+  MOZ_ASSERT(usedFloatArgs == 0);
+
+  if (GetIntArgReg(usedIntArgs, out)) {
+    return true;
+  }
+  // Unfortunately, we have to assume things about the point at which
+  // GetIntArgReg returns false, because we need to know how many registers it
+  // can allocate.
+  usedIntArgs -= NumIntArgRegs;
+  if (usedIntArgs >= NumCallTempNonArgRegs) {
+    return false;
+  }
+  *out = CallTempNonArgRegs[usedIntArgs];
+  return true;
+}
+
+}  // namespace jit
+}  // namespace js
+
+#endif /* jit_mips32_Assembler_mips32_h */