diff --git a/src/app/test/genopcode.h b/src/app/test/genopcode.h
index 16c6b65..408e858 100644
--- a/src/app/test/genopcode.h
+++ b/src/app/test/genopcode.h
@@ -13,7 +13,7 @@
 
 namespace asmgen {
 
-enum { kGenOpCodeInstCount = 2656 };
+enum { kGenOpCodeInstCount = 2670 };
 
 // Generate all instructions asmjit can emit.
 static void opcode(asmjit::X86Assembler& a) {
@@ -50,7 +50,9 @@ static void opcode(asmjit::X86Assembler& a) {
 
   // Base.
   a.adc(al, 1);
+  a.adc(ah, 1);
   a.adc(bl, 1);
+  a.adc(bh, 1);
   a.adc(ax, 1);
   a.adc(bx, 1);
   a.adc(eax, 1);
@@ -61,7 +63,9 @@ static void opcode(asmjit::X86Assembler& a) {
   a.adc(intptr_gp0, gp1);
   a.adc(intptr_gp0, 0);
   a.add(al, 1);
+  a.add(ah, 1);
   a.add(bl, 1);
+  a.add(bh, 1);
   a.add(ax, 1);
   a.add(bx, 1);
   a.add(eax, 1);
@@ -72,7 +76,9 @@ static void opcode(asmjit::X86Assembler& a) {
   a.add(intptr_gp0, gp1);
   a.add(intptr_gp0, 0);
   a.and_(al, 1);
+  a.and_(ah, 1);
   a.and_(bl, 1);
+  a.and_(bh, 1);
   a.and_(ax, 1);
   a.and_(bx, 1);
   a.and_(eax, 1);
@@ -107,7 +113,9 @@ static void opcode(asmjit::X86Assembler& a) {
   a.cld();
   a.cmc();
   a.cmp(al, 1);
+  a.cmp(ah, 1);
   a.cmp(bl, 1);
+  a.cmp(bh, 1);
   a.cmp(ax, 1);
   a.cmp(bx, 1);
   a.cmp(eax, 1);
@@ -158,7 +166,9 @@ static void opcode(asmjit::X86Assembler& a) {
   a.not_(gp0);
   a.not_(intptr_gp0);
   a.or_(al, 1);
+  a.or_(ah, 1);
   a.or_(bl, 1);
+  a.or_(bh, 1);
   a.or_(ax, 1);
   a.or_(bx, 1);
   a.or_(eax, 1);
@@ -202,7 +212,9 @@ static void opcode(asmjit::X86Assembler& a) {
   a.ror(intptr_gp0, 0);
   a.ror(intptr_gp0, 1);
   a.sbb(al, 1);
+  a.sbb(ah, 1);
   a.sbb(bl, 1);
+  a.sbb(bh, 1);
   a.sbb(ax, 1);
   a.sbb(bx, 1);
   a.sbb(eax, 1);
@@ -247,7 +259,9 @@ static void opcode(asmjit::X86Assembler& a) {
   a.stc();
   a.std();
   a.sub(al, 1);
+  a.sub(ah, 1);
   a.sub(bl, 1);
+  a.sub(bh, 1);
   a.sub(ax, 1);
   a.sub(bx, 1);
   a.sub(eax, 1);
@@ -268,7 +282,9 @@ static void opcode(asmjit::X86Assembler& a) {
   a.xchg(intptr_gp0, gp1);
   a.xchg(gp0, intptr_gp1);
   a.xor_(al, 1);
+  a.xor_(ah, 1);
   a.xor_(bl, 1);
+  a.xor_(bh, 1);
   a.xor_(ax, 1);
   a.xor_(bx, 1);
   a.xor_(eax, 1);
diff --git a/src/asmjit/x86/x86assembler.cpp b/src/asmjit/x86/x86assembler.cpp
index b100c99..f402264 100644
--- a/src/asmjit/x86/x86assembler.cpp
+++ b/src/asmjit/x86/x86assembler.cpp
@@ -1192,7 +1192,7 @@ _Prepare:
 
     case kX86InstEncodingIdX86Arith:
       if (encoded == ENC_OPS(Reg, Reg, None)) {
-        opCode +=(o0->getSize() != 1) + 2;
+        opCode += (o0->getSize() != 1) + 2;
         ADD_66H_P_BY_SIZE(o0->getSize());
         ADD_REX_W_BY_SIZE(o0->getSize());
 
@@ -1202,7 +1202,7 @@ _Prepare:
       }
 
       if (encoded == ENC_OPS(Reg, Mem, None)) {
-        opCode +=(o0->getSize() != 1) + 2;
+        opCode += (o0->getSize() != 1) + 2;
         ADD_66H_P_BY_SIZE(o0->getSize());
         ADD_REX_W_BY_SIZE(o0->getSize());
 
@@ -3480,7 +3480,7 @@ _EmitX86Op:
   if (Arch == kArchX64) {
     uint32_t rex = x86RexFromOpCodeAndOptions(opCode, options);
 
-    if (rex) {
+    if (rex & ~static_cast<uint32_t>(_kX86InstOptionNoRex)) {
       rex |= kX86ByteRex;
       EMIT_BYTE(rex);
 
@@ -3508,7 +3508,7 @@ _EmitX86OpWithOpReg:
 
     rex += (opReg >> 3); // Rex.B (0x01).
 
-    if (rex) {
+    if (rex & ~static_cast<uint32_t>(_kX86InstOptionNoRex)) {
       rex |= kX86ByteRex;
       opReg &= 0x7;
       EMIT_BYTE(rex);
@@ -3539,7 +3539,7 @@ _EmitX86R:
     rex += static_cast<uint32_t>(opReg & 0x08) >> 1; // Rex.R (0x04).
     rex += static_cast<uint32_t>(rmReg) >> 3;        // Rex.B (0x01).
 
-    if (rex) {
+    if (rex & ~static_cast<uint32_t>(_kX86InstOptionNoRex)) {
       rex |= kX86ByteRex;
       opReg &= 0x7;
       rmReg &= 0x7;
@@ -3597,7 +3597,7 @@ _EmitX86M:
     rex += static_cast<uint32_t>(mIndex - 8 < 8) << 1; // Rex.X (0x02).
     rex += static_cast<uint32_t>(mBase  - 8 < 8);      // Rex.B (0x01).
 
-    if (rex) {
+    if (rex & ~static_cast<uint32_t>(_kX86InstOptionNoRex)) {
       rex |= kX86ByteRex;
       opReg &= 0x7;
       EMIT_BYTE(rex);
diff --git a/src/asmjit/x86/x86operand.h b/src/asmjit/x86/x86operand.h
index 1faed37..124cd6f 100644
--- a/src/asmjit/x86/x86operand.h
+++ b/src/asmjit/x86/x86operand.h
@@ -666,7 +666,7 @@ struct X86Reg : public Reg {
   //! Get whether the register is Gp register.
   ASMJIT_INLINE bool isGp() const { return _vreg.type <= kX86RegTypeGpq; }
   //! Get whether the register is Gp byte (8-bit) register.
-  ASMJIT_INLINE bool isGpb() const { return _vreg.type <= kX86RegTypeGpbHi; }
+  ASMJIT_INLINE bool isGpb() const { return _vreg.type <= _kX86RegTypePatchedGpbHi; }
   //! Get whether the register is Gp lo-byte (8-bit) register.
   ASMJIT_INLINE bool isGpbLo() const { return _vreg.type == kX86RegTypeGpbLo; }
   //! Get whether the register is Gp hi-byte (8-bit) register.