MIPS: Fix trampoline pool handling in MacroAssembler::BranchShort() for r6.

src/mips64/assembler-mips64.cc

Index: src/mips64/assembler-mips64.cc
diff --git a/src/mips64/assembler-mips64.cc b/src/mips64/assembler-mips64.cc
index 91594d3dd342adbfd27d157ffe45f134de157b20..e0f12ed020f54f3102e95c73acfb599816adff98 100644
--- a/src/mips64/assembler-mips64.cc
+++ b/src/mips64/assembler-mips64.cc
@@ -1344,9 +1344,11 @@ void Assembler::bgezalc(Register rt, int16_t offset) {
 
 
 void Assembler::bgezall(Register rs, int16_t offset) {
-  DCHECK(kArchVariant == kMips64r6);
+  DCHECK(kArchVariant != kMips64r6);
   DCHECK(!(rs.is(zero_reg)));
+  BlockTrampolinePoolScope block_trampoline_pool(this);
   GenInstrImmediate(REGIMM, rs, BGEZALL, offset);
+  BlockTrampolinePoolFor(1);  // For associated delay slot.
 }
 
 
@@ -1409,15 +1411,19 @@ void Assembler::bnezc(Register rs, int32_t offset) {
 
 
 void Assembler::j(int64_t target) {
+  BlockTrampolinePoolScope block_trampoline_pool(this);
   GenInstrJump(J, static_cast<uint32_t>(target >> 2) & kImm26Mask);
+  BlockTrampolinePoolFor(1);  // For associated delay slot.
 }
 
 
 void Assembler::j(Label* target) {
   uint64_t imm = jump_offset(target);
   if (target->is_bound()) {
+    BlockTrampolinePoolScope block_trampoline_pool(this);
     GenInstrJump(static_cast<Opcode>(kJRawMark),
                  static_cast<uint32_t>(imm >> 2) & kImm26Mask);
+    BlockTrampolinePoolFor(1);  // For associated delay slot.
   } else {
     j(imm);

[paul.l..., 2015/11/17 19:59:45]

Doesn't this unbound case also need to be protected? Also for jal and jr below.
If so, these could be moved outside the if block, so they only appear once.

[balazs.kilvady, 2015/11/18 12:22:53]

We should not add protection here as implementation of j() contains protection.

Other thing: I checked that parameter of j should be int32_t, not 64 bits. I did
not put that changes into this CL but would be fine to fix it.

   }
@@ -1427,8 +1433,11 @@ void Assembler::j(Label* target) {
 void Assembler::jal(Label* target) {
   uint64_t imm = jump_offset(target);
   if (target->is_bound()) {
+    BlockTrampolinePoolScope block_trampoline_pool(this);
+    positions_recorder()->WriteRecordedPositions();
     GenInstrJump(static_cast<Opcode>(kJalRawMark),
                  static_cast<uint32_t>(imm >> 2) & kImm26Mask);
+    BlockTrampolinePoolFor(1);  // For associated delay slot.
   } else {
     jal(imm);
   }
@@ -1450,8 +1459,10 @@ void Assembler::jr(Register rs) {
 
 
 void Assembler::jal(int64_t target) {
+  BlockTrampolinePoolScope block_trampoline_pool(this);
   positions_recorder()->WriteRecordedPositions();
   GenInstrJump(JAL, static_cast<uint32_t>(target >> 2) & kImm26Mask);
+  BlockTrampolinePoolFor(1);  // For associated delay slot.
 }