MIPS64: Replace JR/JALR with JIC/JIALC for r6.

src/full-codegen/mips64/full-codegen-mips64.cc

Index: src/full-codegen/mips64/full-codegen-mips64.cc
diff --git a/src/full-codegen/mips64/full-codegen-mips64.cc b/src/full-codegen/mips64/full-codegen-mips64.cc
index a37586440af0f588195d2c061c91a64324cadbbc..07471a0e1c89d0fe7532f50a7e24031682aa847d 100644
--- a/src/full-codegen/mips64/full-codegen-mips64.cc
+++ b/src/full-codegen/mips64/full-codegen-mips64.cc
@@ -4062,7 +4062,12 @@ void BackEdgeTable::PatchAt(Code* unoptimized_code,
                             BackEdgeState target_state,
                             Code* replacement_code) {
   static const int kInstrSize = Assembler::kInstrSize;
-  Address branch_address = pc - 8 * kInstrSize;
+  Address branch_address;
+  if (kArchVariant == kMips64r6) {
+    branch_address = pc - 7 * kInstrSize;
+  } else {
+    branch_address = pc - 8 * kInstrSize;
+  }

[balazs.kilvady, 2016/03/24 17:03:10]

Could you use the same constant-based solution here as on 32-bit part 2 CL? And
for the all of the other pc +/- <magic value> part. Do you plan to create a
separated 64 version of the ... part 2 CL?

[miran.karic, 2016/03/25 09:30:09]

Yes, I was planing to do that the same way as for mips32. When I finish testing
I will upload the CL. These are all the changes I plan to do, the rest of the
code uses j/jal in mips64 so I won't change it. 

   Isolate* isolate = unoptimized_code->GetIsolate();
   CodePatcher patcher(isolate, branch_address, 1);
 
@@ -4092,7 +4097,12 @@ void BackEdgeTable::PatchAt(Code* unoptimized_code,
       patcher.masm()->daddiu(at, zero_reg, 1);
       break;
   }
-  Address pc_immediate_load_address = pc - 6 * kInstrSize;
+  Address pc_immediate_load_address;
+  if (kArchVariant == kMips64r6) {
+    pc_immediate_load_address = pc - 5 * kInstrSize;
+  } else {
+    pc_immediate_load_address = pc - 6 * kInstrSize;
+  }
   // Replace the stack check address in the load-immediate (6-instr sequence)
   // with the entry address of the replacement code.
   Assembler::set_target_address_at(isolate, pc_immediate_load_address,
@@ -4108,12 +4118,24 @@ BackEdgeTable::BackEdgeState BackEdgeTable::GetBackEdgeState(
     Code* unoptimized_code,
     Address pc) {
   static const int kInstrSize = Assembler::kInstrSize;
-  Address branch_address = pc - 8 * kInstrSize;
+  Address branch_address;
+#ifdef DEBUG
+  Address pc_immediate_load_address;
+#endif
+  if (kArchVariant == kMips64r6) {
+    branch_address = pc - 7 * kInstrSize;
 #ifdef DEBUG
-  Address pc_immediate_load_address = pc - 6 * kInstrSize;
+    pc_immediate_load_address = pc - 5 * kInstrSize;
 #endif
+    DCHECK(Assembler::IsBeq(Assembler::instr_at(pc - 6 * kInstrSize)));
+  } else {
+    branch_address = pc - 8 * kInstrSize;
+#ifdef DEBUG
+    pc_immediate_load_address = pc - 6 * kInstrSize;
+#endif
+    DCHECK(Assembler::IsBeq(Assembler::instr_at(pc - 7 * kInstrSize)));
+  }
 
-  DCHECK(Assembler::IsBeq(Assembler::instr_at(pc - 7 * kInstrSize)));
   if (!Assembler::IsAddImmediate(Assembler::instr_at(branch_address))) {
     DCHECK(reinterpret_cast<uint64_t>(
         Assembler::target_address_at(pc_immediate_load_address)) ==