1 files changed, 207 insertions, 3 deletions
diff --git a/js/src/jit/mips-shared/Assembler-mips-shared.cpp b/js/src/jit/mips-shared/Assembler-mips-shared.cpp
index f813eb946..97f27c2e6 100644
--- a/js/src/jit/mips-shared/Assembler-mips-shared.cpp
+++ b/js/src/jit/mips-shared/Assembler-mips-shared.cpp
@@ -92,6 +92,7 @@ void
 AssemblerMIPSShared::finish()
 {
     MOZ_ASSERT(!isFinished);
+    GenerateMixedJumps();
     isFinished = true;
 }
 
@@ -100,13 +101,26 @@ AssemblerMIPSShared::asmMergeWith(const AssemblerMIPSShared& other)
 {
     if (!AssemblerShared::asmMergeWith(size(), other))
         return false;
-    for (size_t i = 0; i < other.numLongJumps(); i++) {
-        size_t off = other.longJumps_[i];
-        addLongJump(BufferOffset(size() + off));
+    for (size_t i = 0; i < other.numMixedJumps(); i++) {
+        const MixedJumpPatch& mjp = other.mixedJumps_[i];
+        addMixedJump(BufferOffset(size() + mjp.src.getOffset()),
+                     size() + mjp.target, mjp.kind);
     }
     return m_buffer.appendBuffer(other.m_buffer);
 }
 
+void
+AssemblerMIPSShared::executableCopy(uint8_t* buffer)
+{
+    MOZ_ASSERT(isFinished);
+    m_buffer.executableCopy(buffer);
+
+    // Patch all mixed jumps during code copy.
+    PatchMixedJumps(buffer);
+
+    AutoFlushICache::setRange(uintptr_t(buffer), m_buffer.size());
+}
+
 uint32_t
 AssemblerMIPSShared::actualIndex(uint32_t idx_) const
 {
@@ -1588,6 +1602,92 @@ AssemblerMIPSShared::bindLater(Label* label, wasm::TrapDesc target)
 }
 
 void
+AssemblerMIPSShared::bind(InstImm* inst, uintptr_t branch, uintptr_t target)
+{
+    intptr_t offset = target - branch;
+
+    // Generate the patchable mixed jump for call.
+    if (inst->extractOpcode() == ((uint32_t)op_jal >> OpcodeShift)) {
+        addMixedJump(BufferOffset(branch), target);
+        return;
+    }
+
+    // If encoded offset is 4, then the jump must be short
+    if (BOffImm16(inst[0]).decode() == 4) {
+        MOZ_ASSERT(BOffImm16::IsInRange(offset));
+        inst[0].setBOffImm16(BOffImm16(offset));
+        inst[1].makeNop();
+        return;
+    }
+
+    if (BOffImm16::IsInRange(offset)) {
+        inst[0].setBOffImm16(BOffImm16(offset));
+        inst[1].makeNop();
+        return;
+    }
+
+    MixedJumpPatch::Kind kind = MixedJumpPatch::NONE;
+    InstImm inst_beq = InstImm(op_beq, zero, zero, BOffImm16(0));
+    if (inst[0].encode() != inst_beq.encode())
+        kind = MixedJumpPatch::CONDITIONAL;
+
+    addMixedJump(BufferOffset(branch), target, kind);
+}
+
+void
+AssemblerMIPSShared::bind(RepatchLabel* label)
+{
+    BufferOffset dest = nextOffset();
+    if (label->used() && !oom()) {
+        // If the label has a use, then change this use to refer to
+        // the bound label;
+        BufferOffset b(label->offset());
+        InstImm* inst = (InstImm*)editSrc(b);
+        InstImm inst_beq = InstImm(op_beq, zero, zero, BOffImm16(0));
+        intptr_t offset = dest.getOffset() - label->offset();
+
+        // If first instruction is j, then this is a mixed jump.
+        // If second instruction is lui, then this is a loop backedge.
+        if (inst[0].extractOpcode() == (uint32_t(op_j) >> OpcodeShift)) {
+            // For unconditional mixed branches generated by jumpWithPatch
+            addMixedJump(b, dest.getOffset(), MixedJumpPatch::PATCHABLE);
+        } else if (inst[1].extractOpcode() == (uint32_t(op_lui) >> OpcodeShift) ||
+                   BOffImm16::IsInRange(offset))
+        {
+            // Handle code produced by:
+            //     backedgeJump
+            MOZ_ASSERT(BOffImm16::IsInRange(offset));
+            MOZ_ASSERT(inst[0].extractOpcode() == (uint32_t(op_beq) >> OpcodeShift) ||
+                       inst[0].extractOpcode() == (uint32_t(op_bne) >> OpcodeShift) ||
+                       inst[0].extractOpcode() == (uint32_t(op_blez) >> OpcodeShift) ||
+                       inst[0].extractOpcode() == (uint32_t(op_bgtz) >> OpcodeShift));
+            inst[0].setBOffImm16(BOffImm16(offset));
+        } else if (inst[0].encode() == inst_beq.encode()) {
+            // Handle open mixed unconditional jumps created by
+            // MacroAssemblerMIPSShared::ma_b(..., wasm::Trap, ...).
+            // We need to add it to mixed jumps array here.
+            // See MacroAssemblerMIPS::branchWithCode().
+            MOZ_ASSERT(inst[1].encode() == NopInst);
+            addMixedJump(b, dest.getOffset(), MixedJumpPatch::PATCHABLE);
+            inst[0] = InstJump(op_j, JOffImm26(0)).encode();
+        } else {
+            // Handle open mixed conditional jumps created by
+            // MacroAssemblerMIPSShared::ma_b(..., wasm::Trap, ...).
+            inst[0] = invertBranch(inst[0], BOffImm16(4 * sizeof(uint32_t)));
+            // No need for a "nop" here because we can clobber scratch.
+            // We need to add it to mixed jumps array here.
+            // See MacroAssemblerMIPS::branchWithCode().
+            MOZ_ASSERT(inst[1].encode() == NopInst);
+            MOZ_ASSERT(inst[2].encode() == NopInst);
+            MOZ_ASSERT(inst[3].encode() == NopInst);
+            addMixedJump(b, dest.getOffset(), MixedJumpPatch::PATCHABLE);
+            inst[2] = InstJump(op_j, JOffImm26(0)).encode();
+        }
+    }
+    label->bind(dest.getOffset());
+}
+
+void
 AssemblerMIPSShared::retarget(Label* label, Label* target)
 {
     if (label->used() && !oom()) {
@@ -1653,6 +1753,25 @@ AssemblerMIPSShared::PatchWrite_Imm32(CodeLocationLabel label, Imm32 imm)
     *(raw - 1) = imm.value;
 }
 
+uint32_t
+AssemblerMIPSShared::PatchWrite_NearCallSize()
+{
+    return 2 * sizeof(uint32_t);
+}
+
+void
+AssemblerMIPSShared::PatchWrite_NearCall(CodeLocationLabel start, CodeLocationLabel toCall)
+{
+    Instruction* inst = (Instruction*) start.raw();
+
+    // Overwrite whatever instruction used to be here with a call.
+    inst[0] = InstJump(op_jal, JOffImm26(uintptr_t(toCall.raw())));
+    inst[1] = InstNOP();
+
+    // Ensure everyone sees the code that was just written into memory.
+    AutoFlushICache::flush(uintptr_t(inst), PatchWrite_NearCallSize());
+}
+
 uint8_t*
 AssemblerMIPSShared::NextInstruction(uint8_t* inst_, uint32_t* count)
 {
@@ -1662,6 +1781,82 @@ AssemblerMIPSShared::NextInstruction(uint8_t* inst_, uint32_t* count)
     return reinterpret_cast<uint8_t*>(inst->next());
 }
 
+Instruction*
+AssemblerMIPSShared::GetInstructionImmediateFromJump(Instruction* jump)
+{
+    if (jump->extractOpcode() == ((uint32_t)op_j >> OpcodeShift) ||
+        jump->extractOpcode() == ((uint32_t)op_jal >> OpcodeShift))
+    {
+        InstJump* j = (InstJump*) jump;
+        uintptr_t base = (uintptr_t(j) >> Imm28Bits) << Imm28Bits;
+        uint32_t index = j->extractImm26Value() << 2;
+
+        jump = (Instruction*)(base | index);
+        if (jump->extractOpcode() != ((uint32_t)op_lui >> OpcodeShift))
+            jump = jump->next();
+    }
+
+    return jump;
+}
+
+void
+AssemblerMIPSShared::PatchMixedJump(uint8_t* src, uint8_t* mid, uint8_t* target)
+{
+    InstImm* b = (InstImm*)src;
+    uint32_t opcode = b->extractOpcode();
+    int offset;
+
+    if (mid) {
+        int o = 0;
+        InstImm* insn = (InstImm*)mid;
+
+        offset = intptr_t(mid);
+        if (insn->extractOpcode() != ((uint32_t)op_lui >> OpcodeShift)) {
+            o = 1 * sizeof(uint32_t);
+            Assembler::PatchInstructionImmediate(mid + Assembler::InstructionImmediateSize() +
+                                                 2 * sizeof(uint32_t), PatchedImmPtr(&b[2]));
+        }
+        Assembler::PatchInstructionImmediate(mid + o, PatchedImmPtr(target));
+    } else {
+        offset = intptr_t(target);
+    }
+
+    if (((uint32_t)op_j >> OpcodeShift) == opcode ||
+        ((uint32_t)op_jal >> OpcodeShift) == opcode)
+    {
+        InstJump* j = (InstJump*)b;
+
+        j->setJOffImm26(JOffImm26(offset));
+    } else {
+        b[0] = InstJump(op_j, JOffImm26(offset)).encode();
+    }
+}
+
+void
+AssemblerMIPSShared::PatchMixedJumps(uint8_t* buffer)
+{
+    // Patch all mixed jumps.
+    for (size_t i = 0; i < numMixedJumps(); i++) {
+        MixedJumpPatch& mjp = mixedJump(i);
+        uint8_t* src = buffer + mjp.src.getOffset();
+        uint8_t* mid = nullptr;
+        uint8_t* target = buffer + mjp.target;
+        InstImm* b = (InstImm*)src;
+
+        if (mjp.mid.assigned()) {
+            mid = buffer + mjp.mid.getOffset();
+            if (MixedJumpPatch::CONDITIONAL & mjp.kind) {
+                InstImm* bc = (InstImm*)(buffer + mjp.mid.getOffset());
+                BOffImm16 offset(Assembler::InstructionImmediateSize() + 2 * sizeof(uint32_t));
+                bc[0] = invertBranch(b[0], offset);
+            }
+        }
+
+        PatchMixedJump(src, mid, target);
+        b[1].makeNop();
+    }
+}
+
 // Since there are no pools in MIPS implementation, this should be simple.
 Instruction*
 Instruction::next()
@@ -1744,3 +1939,12 @@ AssemblerMIPSShared::ToggleToCmp(CodeLocationLabel inst_)
     AutoFlushICache::flush(uintptr_t(inst), 4);
 }
 
+void
+AssemblerMIPSShared::UpdateLuiOriValue(Instruction* inst0, Instruction* inst1, uint32_t value)
+{
+    MOZ_ASSERT(inst0->extractOpcode() == ((uint32_t)op_lui >> OpcodeShift));
+    MOZ_ASSERT(inst1->extractOpcode() == ((uint32_t)op_ori >> OpcodeShift));
+
+    ((InstImm*) inst0)->setImm16(Imm16::Upper(Imm32(value)));
+    ((InstImm*) inst1)->setImm16(Imm16::Lower(Imm32(value)));
+}