[turbofan] Improve codegen for 8- and 16-bit memory comparisons on Intel platforms

test/cctest/test-assembler-x64.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // 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 183 matching lines @@
   assm.GetCode(&desc);
   // Call the function from C++.
   int result =  FUNCTION_CAST<F2>(buffer)(3, 2);
   CHECK_EQ(0, result);
   result =  FUNCTION_CAST<F2>(buffer)(0x100000000l, 0x100000000l);
   CHECK_EQ(1, result);
   result =  FUNCTION_CAST<F2>(buffer)(-0x100000000l, 0x100000000l);
   CHECK_EQ(-1, result);
 }
 
-TEST(AssemblerX64testbwOperation) {
+TEST(AssemblerX64testbwqOperation) {
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());
   // Allocate an executable page of memory.
   size_t actual_size;
   byte* buffer = static_cast<byte*>(v8::base::OS::Allocate(
       Assembler::kMinimalBufferSize, &actual_size, true));
   CHECK(buffer);
   Assembler assm(CcTest::i_isolate(), buffer, static_cast<int>(actual_size));
 
   __ pushq(rbx);
@@ skipping 116 matching lines @@
   __ j(zero, &bad);
   __ testb(r12, r11);
   __ j(zero, &bad);
   __ testb(r11, r12);
   __ j(zero, &bad);
   __ testw(r12, r11);
   __ j(zero, &bad);
   __ testw(r11, r12);
   __ j(zero, &bad);
 
+  // Test sign-extended imediate tests
+  __ movq(r11, Immediate(2));
+  __ shlq(r11, Immediate(32));
+  __ testq(r11, Immediate(-1));
+  __ j(zero, &bad);
+
   // All tests passed
   __ movq(rax, Immediate(1));
   __ jmp(&done);
 
   __ bind(&bad);
   __ movq(rax, Immediate(0));
   __ bind(&done);
 
   __ popq(r15);
   __ popq(r14);
@@ skipping 2156 matching lines @@
 #ifdef OBJECT_PRINT
   OFStream os(stdout);
   code->Print(os);
 #endif
 
   F9 f = FUNCTION_CAST<F9>(code->entry());
   CHECK_EQ(-1.5, f(1.5, -1.5));
 }
 
 #undef __