Bug 1287349 - wasm: MIPS: Implement WasmBoundsCheck/Load/Store in Codegen. r=luke

---
 .../jit/mips-shared/CodeGenerator-mips-shared.cpp  | 130 +++++++++++++++++++++
 js/src/jit/mips-shared/CodeGenerator-mips-shared.h |   3 +
 2 files changed, 133 insertions(+)

js/src/jit/mips-shared/CodeGenerator-mips-shared.cpp

@@ -1654,6 +1654,136 @@ CodeGeneratorMIPSShared::visitAsmJSCall(LAsmJSCall* ins)
     emitAsmJSCall(ins);
 }
 
+void
+CodeGeneratorMIPSShared::visitWasmBoundsCheck(LWasmBoundsCheck* ins)
+{
+    MWasmBoundsCheck* mir = ins->mir();
+
+    uint32_t offset = mir->offset();
+    if (offset > INT32_MAX) {
+        masm.jump(wasm::JumpTarget::OutOfBounds);
+        return;
+    }
+
+    uint32_t endOffset = mir->endOffset();
+    Register ptr = ToRegister(ins->ptr());
+
+    masm.move32(Imm32(endOffset), SecondScratchReg);
+    masm.addPtr(ptr, SecondScratchReg);
+
+    // Detect unsigned overflow.
+    masm.ma_b(SecondScratchReg, ptr, wasm::JumpTarget::OutOfBounds, Assembler::LessThan);
+
+    BufferOffset bo = masm.ma_BoundsCheck(ScratchRegister);
+    masm.ma_b(SecondScratchReg, ScratchRegister, wasm::JumpTarget::OutOfBounds, Assembler::Above);
+    masm.append(wasm::BoundsCheck(bo.getOffset()));
+}
+
+void
+CodeGeneratorMIPSShared::visitWasmLoad(LWasmLoad* lir)
+{
+    const MWasmLoad* mir = lir->mir();
+
+    MOZ_ASSERT(!mir->barrierBefore() && !mir->barrierAfter(), "atomics NYI");
+
+    uint32_t offset = mir->offset();
+    if (offset > INT32_MAX) {
+        // This is unreachable because of bounds checks.
+        masm.breakpoint();
+        return;
+    }
+
+    Register ptr = ToRegister(lir->ptr());
+
+    // Maybe add the offset.
+    if (offset) {
+        Register ptrPlusOffset = ToRegister(lir->ptrCopy());
+        masm.addPtr(Imm32(offset), ptrPlusOffset);
+        ptr = ptrPlusOffset;
+    } else {
+        MOZ_ASSERT(lir->ptrCopy()->isBogusTemp());
+    }
+
+    unsigned byteSize = mir->byteSize();
+    bool isSigned;
+    bool isFloat = false;
+
+    switch (mir->accessType()) {
+      case Scalar::Int8:    isSigned = true;  break;
+      case Scalar::Uint8:   isSigned = false; break;
+      case Scalar::Int16:   isSigned = true;  break;
+      case Scalar::Uint16:  isSigned = false; break;
+      case Scalar::Int32:   isSigned = true;  break;
+      case Scalar::Uint32:  isSigned = false; break;
+      case Scalar::Float64: isFloat  = true;  break;
+      case Scalar::Float32: isFloat  = true;  break;
+      default: MOZ_CRASH("unexpected array type");
+    }
+
+    if (isFloat) {
+        if (byteSize == 4) {
+            masm.loadFloat32(BaseIndex(HeapReg, ptr, TimesOne), ToFloatRegister(lir->output()));
+        } else
+            masm.loadDouble(BaseIndex(HeapReg, ptr, TimesOne), ToFloatRegister(lir->output()));
+    } else {
+        masm.ma_load(ToRegister(lir->output()), BaseIndex(HeapReg, ptr, TimesOne),
+                      static_cast<LoadStoreSize>(8 * byteSize), isSigned ? SignExtend : ZeroExtend);
+    }
+}
+
+void
+CodeGeneratorMIPSShared::visitWasmStore(LWasmStore* lir)
+{
+    const MWasmStore* mir = lir->mir();
+
+    MOZ_ASSERT(!mir->barrierBefore() && !mir->barrierAfter(), "atomics NYI");
+
+    uint32_t offset = mir->offset();
+    if (offset > INT32_MAX) {
+        // This is unreachable because of bounds checks.
+        masm.breakpoint();
+        return;
+    }
+
+    Register ptr = ToRegister(lir->ptr());
+
+    // Maybe add the offset.
+    if (offset) {
+        Register ptrPlusOffset = ToRegister(lir->ptrCopy());
+        masm.addPtr(Imm32(offset), ptrPlusOffset);
+        ptr = ptrPlusOffset;
+    } else {
+        MOZ_ASSERT(lir->ptrCopy()->isBogusTemp());
+    }
+
+    unsigned byteSize = mir->byteSize();
+    bool isSigned;
+    bool isFloat = false;
+
+    switch (mir->accessType()) {
+      case Scalar::Int8:    isSigned = true;  break;
+      case Scalar::Uint8:   isSigned = false; break;
+      case Scalar::Int16:   isSigned = true;  break;
+      case Scalar::Uint16:  isSigned = false; break;
+      case Scalar::Int32:   isSigned = true;  break;
+      case Scalar::Uint32:  isSigned = false; break;
+      case Scalar::Int64:   isSigned = true;  break;
+      case Scalar::Float64: isFloat  = true;  break;
+      case Scalar::Float32: isFloat  = true;  break;
+      default: MOZ_CRASH("unexpected array type");
+    }
+
+    if (isFloat) {
+        if (byteSize == 4) {
+            masm.storeFloat32(ToFloatRegister(lir->value()), BaseIndex(HeapReg, ptr, TimesOne));
+        } else
+            masm.storeDouble(ToFloatRegister(lir->value()), BaseIndex(HeapReg, ptr, TimesOne));
+    } else {
+        masm.ma_store(ToRegister(lir->value()), BaseIndex(HeapReg, ptr, TimesOne),
+                      static_cast<LoadStoreSize>(8 * byteSize), isSigned ? SignExtend : ZeroExtend);
+    }
+}
+
 void
 CodeGeneratorMIPSShared::visitAsmJSLoadHeap(LAsmJSLoadHeap* ins)
 {

js/src/jit/mips-shared/CodeGenerator-mips-shared.h

@@ -193,6 +193,9 @@ class CodeGeneratorMIPSShared : public CodeGeneratorShared
     void visitLoadTypedArrayElementStatic(LLoadTypedArrayElementStatic* ins);
     void visitStoreTypedArrayElementStatic(LStoreTypedArrayElementStatic* ins);
     void visitAsmJSCall(LAsmJSCall* ins);
+    void visitWasmBoundsCheck(LWasmBoundsCheck* ins);
+    void visitWasmLoad(LWasmLoad* ins);
+    void visitWasmStore(LWasmStore* ins);
     void visitAsmJSLoadHeap(LAsmJSLoadHeap* ins);
     void visitAsmJSStoreHeap(LAsmJSStoreHeap* ins);
     void visitAsmJSCompareExchangeHeap(LAsmJSCompareExchangeHeap* ins);