MIPS[64] Port "[wasm] Introduce jump table"

Port of 733b7c82

Original description:
> [wasm] Introduce jump table
>
> This introduces the concept of a jump table for WebAssembly, which is
> used for every direct and indirect call to any WebAssembly function.
> For lazy compilation, it will initially contain code to call the
> WasmCompileLazy builtin, where it passes the function index to be
> called.
> For non-lazy-compilation, it will contain a jump to the actual code.
> The jump table allows to easily redirect functions for lazy
> compilation, tier-up, debugging and (in the future) code aging. After
> this CL, we will not need to patch existing code any more for any of
> these operations.
>
> R=mstarzinger@chromium.org, titzer@chromium.org
>
> Bug: v8:7758
> Change-Id: I45f9983c2b06ae81bf5ce9847f4542fb48844a4f
> Reviewed-on: https://chromium-review.googlesource.com/1097075
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Reviewed-by: Ben Titzer <titzer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#53805}

Change-Id: Ifa7c2abe89a6dc5dbb03a547db2fab68e292f344
Reviewed-on: https://chromium-review.googlesource.com/1107630
Commit-Queue: Sreten Kovacevic <sreten.kovacevic@mips.com>
Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53893}

src/builtins/mips/builtins-mips.cc

@@ -2351,6 +2351,9 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
+  // The function index was put in t0 by the jump table trampoline.
+  // Convert to Smi for the runtime call.
+  __ SmiTag(t0);
   {
     TrapOnAbortScope trap_on_abort_scope(masm);  // Avoid calls to Abort.
     FrameScope scope(masm, StackFrame::WASM_COMPILE_LAZY);
@@ -2364,8 +2367,9 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     __ MultiPush(gp_regs);
     __ MultiPushFPU(fp_regs);
 
-    // Pass the WASM instance as an explicit argument to WasmCompileLazy.
-    __ push(kWasmInstanceRegister);
+    // Pass instance and function index as an explicit arguments to the runtime
+    // function.
+    __ Push(kWasmInstanceRegister, t0);
     // Load the correct CEntry builtin from the instance object.
     __ lw(a2, FieldMemOperand(kWasmInstanceRegister,
                               WasmInstanceObject::kCEntryStubOffset));

src/builtins/mips64/builtins-mips64.cc

@@ -2368,6 +2368,9 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
+  // The function index was put in t0 by the jump table trampoline.
+  // Convert to Smi for the runtime call
+  __ SmiTag(t0);
   {
     TrapOnAbortScope trap_on_abort_scope(masm);  // Avoid calls to Abort.
     FrameScope scope(masm, StackFrame::WASM_COMPILE_LAZY);
@@ -2382,8 +2385,9 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     __ MultiPush(gp_regs);
     __ MultiPushFPU(fp_regs);
 
-    // Pass the WASM instance as an explicit argument to WasmCompileLazy.
-    __ push(kWasmInstanceRegister);
+    // Pass instance and function index as an explicit arguments to the runtime
+    // function.
+    __ Push(kWasmInstanceRegister, t0);
     // Load the correct CEntry builtin from the instance object.
     __ Ld(a2, FieldMemOperand(kWasmInstanceRegister,
                               WasmInstanceObject::kCEntryStubOffset));

src/wasm/jump-table-assembler.cc

@@ -161,6 +161,27 @@ void JumpTableAssembler::NopBytes(int bytes) {
   }
 }
 
+#elif V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
+void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
+                                                 Address lazy_compile_target) {
+  li(t0, func_index);  // max. 2 instr
+  // Jump produces max. 4 instructions for 32-bit platform
+  // and max. 6 instructions for 64-bit platform.
+  Jump(lazy_compile_target, RelocInfo::NONE);
+}
+
+void JumpTableAssembler::EmitJumpSlot(Address target) {
+  Jump(target, RelocInfo::NONE);
+}
+
+void JumpTableAssembler::NopBytes(int bytes) {
+  DCHECK_LE(0, bytes);
+  DCHECK_EQ(0, bytes % kInstrSize);
+  for (; bytes > 0; bytes -= kInstrSize) {
+    nop();
+  }
+}
+
 #elif V8_TARGET_ARCH_PPC
 void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
                                                  Address lazy_compile_target) {

src/wasm/jump-table-assembler.h

@@ -46,6 +46,10 @@ class JumpTableAssembler : public TurboAssembler {
   static constexpr int kJumpTableSlotSize = 48;
 #elif V8_TARGET_ARCH_PPC
   static constexpr int kJumpTableSlotSize = 24;
+#elif V8_TARGET_ARCH_MIPS
+  static constexpr int kJumpTableSlotSize = 6 * kInstrSize;
+#elif V8_TARGET_ARCH_MIPS64
+  static constexpr int kJumpTableSlotSize = 8 * kInstrSize;
 #else
   static constexpr int kJumpTableSlotSize = 1;
 #endif