MIPS: Fix dd() implementations for compact branches.

test/cctest/test-macro-assembler-mips.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 243 matching lines @@
   F1 f = FUNCTION_CAST<F1>(code->entry());
   for (int i = 0; i < kNumCases; ++i) {
     int res =
         reinterpret_cast<int>(CALL_GENERATED_CODE(isolate, f, i, 0, 0, 0, 0));
     ::printf("f(%d) = %d\n", i, res);
     CHECK_EQ(values[i], res);
   }
 }
 
 
+TEST(jump_tables5) {
+  if (IsMipsArchVariant(kMips32r6)) return;

[paul.l..., 2016/01/12 01:13:40]

I suspect this should be ! IsMipsArchVariant(kMips32r6)

You use a bc() instruction below which is only r6.

[balazs.kilvady, 2016/01/12 16:32:11]

Done.

+
+  // Similar to test-assembler-mips jump_tables1, with extra test for branch
+  // trampoline required before emission of the dd table (where trampolines are
+  // blocked), and proper transition to long-branch mode.
+  // Regression test for v8:4294.

[paul.l..., 2016/01/12 01:13:40]

Is this still a regression for that issue? Or was this just cut/paste from
above?

[balazs.kilvady, 2016/01/12 16:32:11]

Done.

+  CcTest::InitializeVM();
+  Isolate* isolate = CcTest::i_isolate();
+  HandleScope scope(isolate);
+  MacroAssembler assembler(isolate, nullptr, 0,
+                           v8::internal::CodeObjectRequired::kYes);
+  MacroAssembler* masm = &assembler;
+
+  const int kNumCases = 512;
+  int values[kNumCases];
+  isolate->random_number_generator()->NextBytes(values, sizeof(values));
+  Label labels[kNumCases];
+  Label done;
+
+  __ addiu(sp, sp, -4);
+  __ sw(ra, MemOperand(sp));
+
+  __ Align(8);
+  {
+    __ BlockTrampolinePoolFor(kNumCases * 2 + 7 + 1);
+    PredictableCodeSizeScope predictable(
+        masm, kNumCases * kPointerSize + ((7 + 1) * Assembler::kInstrSize));
+    Label here;
+
+    __ bal(&here);
+    __ sll(at, a0, 3);  // In delay slot.
+    __ bind(&here);
+    __ addu(at, at, ra);
+    __ lw(at, MemOperand(at, 6 * Assembler::kInstrSize));
+    __ jalr(at);
+    __ nop();  // Branch delay slot nop.
+    __ bc(&done);
+    for (int i = 0; i < kNumCases; ++i) {
+      __ dd(&labels[i]);
+    }
+  }
+
+  for (int i = 0; i < kNumCases; ++i) {
+    __ bind(&labels[i]);
+    __ lui(v0, (values[i] >> 16) & 0xffff);
+    __ ori(v0, v0, values[i] & 0xffff);
+    __ jr(ra);
+    __ nop();
+  }
+
+  __ bind(&done);
+  __ lw(ra, MemOperand(sp));
+  __ addiu(sp, sp, 4);
+  __ jr(ra);
+  __ nop();
+
+  CodeDesc desc;
+  masm->GetCode(&desc);
+  Handle<Code> code = isolate->factory()->NewCode(
+      desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
+#ifdef OBJECT_PRINT
+  code->Print(std::cout);
+#endif
+  F1 f = FUNCTION_CAST<F1>(code->entry());
+  for (int i = 0; i < kNumCases; ++i) {
+    int64_t res = reinterpret_cast<int64_t>(
+        CALL_GENERATED_CODE(isolate, f, i, 0, 0, 0, 0));
+    ::printf("f(%d) = %" PRId64 "\n", i, res);
+    CHECK_EQ(values[i], res);
+  }
+}
+
+
 static uint32_t run_lsa(uint32_t rt, uint32_t rs, int8_t sa) {
   Isolate* isolate = CcTest::i_isolate();
   HandleScope scope(isolate);
   MacroAssembler assembler(isolate, nullptr, 0,
                            v8::internal::CodeObjectRequired::kYes);
   MacroAssembler* masm = &assembler;
 
   __ Lsa(v0, a0, a1, sa);
   __ jr(ra);
   __ nop();
@@ skipping 62 matching lines @@
   size_t nr_test_cases = sizeof(tc) / sizeof(TestCaseLsa);
   for (size_t i = 0; i < nr_test_cases; ++i) {
     uint32_t res = run_lsa(tc[i].rt, tc[i].rs, tc[i].sa);
     PrintF("0x%x =? 0x%x == lsa(v0, %x, %x, %hhu)\n", tc[i].expected_res, res,
            tc[i].rt, tc[i].rs, tc[i].sa);
     CHECK_EQ(tc[i].expected_res, res);
   }
 }
 
 #undef __