[mips][wasm][liftoff] Allow loads from negative indices

Port commit 4765c70f

Change-Id: I1149eb3317613627e2cef4e6c9ad38f044e96fe0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2576444Reviewed-by: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Auto-Submit: Liu yu <liuyu@loongson.cn>
Cr-Commit-Position: refs/heads/master@{#71633}

src/wasm/baseline/mips/liftoff-assembler-mips.h

@@ -415,7 +415,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
                                          Register offset_reg,
                                          int32_t offset_imm,
                                          LiftoffRegList pinned) {
-  DCHECK_GE(offset_imm, 0);
   STATIC_ASSERT(kTaggedSize == kInt32Size);
   Load(LiftoffRegister(dst), src_addr, offset_reg,
        static_cast<uint32_t>(offset_imm), LoadType::kI32Load, pinned);

src/wasm/baseline/mips64/liftoff-assembler-mips64.h

@@ -73,9 +73,10 @@ inline MemOperand GetStackSlot(int offset) { return MemOperand(fp, -offset); }
 
 inline MemOperand GetInstanceOperand() { return GetStackSlot(kInstanceOffset); }
 
+template <typename T>
 inline MemOperand GetMemOp(LiftoffAssembler* assm, Register addr,
-                           Register offset, uintptr_t offset_imm) {
-  if (is_uint31(offset_imm)) {
+                           Register offset, T offset_imm) {
+  if (is_int32(offset_imm)) {
     int32_t offset_imm32 = static_cast<int32_t>(offset_imm);
     if (offset == no_reg) return MemOperand(addr, offset_imm32);
     assm->daddu(kScratchReg, addr, offset);
@@ -401,18 +402,15 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
                                          Register offset_reg,
                                          int32_t offset_imm,
                                          LiftoffRegList pinned) {
-  DCHECK_GE(offset_imm, 0);
   STATIC_ASSERT(kTaggedSize == kInt64Size);
-  Load(LiftoffRegister(dst), src_addr, offset_reg,
-       static_cast<uint32_t>(offset_imm), LoadType::kI64Load, pinned);
+  MemOperand src_op = liftoff::GetMemOp(this, src_addr, offset_reg, offset_imm);
+  Ld(dst, src_op);
 }
 
 void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                                           int32_t offset_imm,
                                           LiftoffRegister src,
                                           LiftoffRegList pinned) {
-  DCHECK_GE(offset_imm, 0);
-  DCHECK_LE(offset_imm, std::numeric_limits<int32_t>::max());
   STATIC_ASSERT(kTaggedSize == kInt64Size);
   Register scratch = pinned.set(GetUnusedRegister(kGpReg, pinned)).gp();
   Sd(src.gp(), MemOperand(dst_addr, offset_imm));