Merge "Add cmpb instruction to x86 and x86_64 assembler"

compiler/utils/x86/assembler_x86.cc

@@ -1030,6 +1030,14 @@ void X86Assembler::xchgl(Register reg, const Address& address) {
 }
 
 
+void X86Assembler::cmpb(const Address& address, const Immediate& imm) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0x80);
+  EmitOperand(7, address);
+  EmitUint8(imm.value() & 0xFF);
+}
+
+
 void X86Assembler::cmpw(const Address& address, const Immediate& imm) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0x66);

compiler/utils/x86/assembler_x86.h

@@ -479,6 +479,7 @@ class X86Assembler FINAL : public Assembler {
   void xchgl(Register dst, Register src);
   void xchgl(Register reg, const Address& address);
 
+  void cmpb(const Address& address, const Immediate& imm);
   void cmpw(const Address& address, const Immediate& imm);
 
   void cmpl(Register reg, const Immediate& imm);

compiler/utils/x86/assembler_x86_test.cc

@@ -389,4 +389,10 @@ TEST_F(AssemblerX86Test, NearLabel) {
   DriverStr(expected, "near_label");
 }
 
+TEST_F(AssemblerX86Test, Cmpb) {
+  GetAssembler()->cmpb(x86::Address(x86::EDI, 128), x86::Immediate(0));
+  const char* expected = "cmpb $0, 128(%EDI)\n";
+  DriverStr(expected, "cmpb");
+}
+
 }  // namespace art

compiler/utils/x86_64/assembler_x86_64.cc

@@ -1224,6 +1224,16 @@ void X86_64Assembler::xchgl(CpuRegister reg, const Address& address) {
 }
 
 
+void X86_64Assembler::cmpb(const Address& address, const Immediate& imm) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  CHECK(imm.is_int32());
+  EmitOptionalRex32(address);
+  EmitUint8(0x80);
+  EmitOperand(7, address);
+  EmitUint8(imm.value() & 0xFF);
+}
+
+
 void X86_64Assembler::cmpw(const Address& address, const Immediate& imm) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   CHECK(imm.is_int32());

compiler/utils/x86_64/assembler_x86_64.h

@@ -506,6 +506,7 @@ class X86_64Assembler FINAL : public Assembler {
   void xchgq(CpuRegister dst, CpuRegister src);
   void xchgl(CpuRegister reg, const Address& address);
 
+  void cmpb(const Address& address, const Immediate& imm);
   void cmpw(const Address& address, const Immediate& imm);
 
   void cmpl(CpuRegister reg, const Immediate& imm);

compiler/utils/x86_64/assembler_x86_64_test.cc

@@ -1637,4 +1637,11 @@ TEST_F(AssemblerX86_64Test, Repecmpsq) {
   DriverStr(expected, "Repecmpsq");
 }
 
+TEST_F(AssemblerX86_64Test, Cmpb) {
+  GetAssembler()->cmpb(x86_64::Address(x86_64::CpuRegister(x86_64::RDI), 128),
+                       x86_64::Immediate(0));
+  const char* expected = "cmpb $0, 128(%RDI)\n";
+  DriverStr(expected, "cmpb");
+}
+
 }  // namespace art