MIPS: pre-crankshaft updates to code-stubs and stub-cache (3/3)

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 4c48ef183c2c7789ea2618865f03be5894eae7d4..5fd95645068bdaf69acd1f5a0def08e02ee4f2b8 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -814,6 +814,20 @@ void MacroAssembler::MultiPopReversedFPU(RegList regs) {
 }
 
 
+void MacroAssembler::FlushICache(Register address, unsigned instructions) {
+  RegList saved_regs = kJSCallerSaved | ra.bit();
+  MultiPush(saved_regs);
+
+  // Save to a0 in case address == t0.
+  Move(a0, address);
+  PrepareCallCFunction(2, t0);
+
+  li(a1, instructions * kInstrSize);
+  CallCFunction(ExternalReference::flush_icache_function(isolate()), 2);
+  MultiPop(saved_regs);
+}
+
+
 void MacroAssembler::Ext(Register rt,
                          Register rs,
                          uint16_t pos,
@@ -4342,6 +4356,37 @@ void MacroAssembler::CallCFunctionHelper(Register function,
 #undef BRANCH_ARGS_CHECK
 
 
+void MacroAssembler::PatchRelocatedValue(Register li_location,
+                                         Register scratch,
+                                         Register new_value) {
+  lw(scratch, MemOperand(li_location));
+  // At this point scratch is a lui(at, ...) instruction.
+  if (emit_debug_code()) {
+    And(scratch, scratch, kOpcodeMask);
+    Check(eq, "The instruction to patch should be a lui.",
+        scratch, Operand(LUI));
+    lw(scratch, MemOperand(li_location));
+  }
+  srl(t9, new_value, kImm16Bits);
+  Ins(scratch, t9, 0, kImm16Bits);
+  sw(scratch, MemOperand(li_location));
+
+  lw(scratch, MemOperand(li_location, kInstrSize));
+  // scratch is now ori(at, ...).
+  if (emit_debug_code()) {
+    And(scratch, scratch, kOpcodeMask);
+    Check(eq, "The instruction to patch should be an ori.",
+        scratch, Operand(ORI));
+    lw(scratch, MemOperand(li_location, kInstrSize));
+  }
+  Ins(scratch, new_value, 0, kImm16Bits);
+  sw(scratch, MemOperand(li_location, kInstrSize));
+
+  // Update the I-cache so the new lui and ori can be executed.
+  FlushICache(li_location, 2);
+}
+
+
 void MacroAssembler::LoadInstanceDescriptors(Register map,
                                              Register descriptors) {
   lw(descriptors,