diff --git a/InstructionSets/PowerPC/Instruction.hpp b/InstructionSets/PowerPC/Instruction.hpp
index a0694d74c..b0b742791 100644
--- a/InstructionSets/PowerPC/Instruction.hpp
+++ b/InstructionSets/PowerPC/Instruction.hpp
@@ -56,6 +56,14 @@ enum class BranchOption: uint32_t {
 	Always 				= 0b1010,
 };
 
+
+/// @returns @c 0 if reg == 0; @c ~0 otherwise.
+/// @discussion Provides a branchless way to substitute the value 0 for the value of r0
+/// in affected instructions.
+template <typename IntT> constexpr IntT is_zero_mask(uint32_t reg) {
+	return ~IntT((reg - 1) >> 5);
+}
+
 enum class Operation: uint8_t {
 	Undefined,
 
@@ -632,7 +640,30 @@ enum class Operation: uint8_t {
 	/// rD()
 	mfcr,
 
-	mffsx, mfmsr, mfspr, mfsr, mfsrin,
+	/// Move from FPSCR.
+	/// mffs mffs.
+	/// frD()	[rc()]
+	mffsx,
+
+	/// Move from machine state register.
+	/// mfmsr
+	/// rD()
+	mfmsr,
+
+	/// Move from special purpose record.
+	/// mfmsr
+	/// rD(), spr()
+	mfspr,
+
+	/// Move from segment register.
+	/// mfsr
+	/// rD(), sr()
+	mfsr,
+
+	/// Move from segment register indirect.
+	/// mfsrin
+	/// rD(), rB()
+	mfsrin,
 
 	/// Move to condition register fields.
 	/// mtcrf
@@ -659,7 +690,25 @@ enum class Operation: uint8_t {
 	/// crfD(), imm()
 	mtfsfix,
 
-	mtmsr, mtspr, mtsr, mtsrin,
+	/// Move to FPSCR.
+	/// mtfs
+	/// frS()
+	mtmsr,
+
+	/// Move to special purpose record.
+	/// mtmsr
+	/// rD(), spr()
+	mtspr,
+
+	/// Move to segment register.
+	/// mfsr
+	/// sr(), rS()
+	mtsr,
+
+	/// Move to segment register indirect.
+	/// mtsrin
+	/// rD(), rB()
+	mtsrin,
 
 	/// Multiply high word.
 	/// mulhw mulgw.
@@ -895,7 +944,19 @@ enum class Operation: uint8_t {
 	//
 	// MARK: - Supervisor, optional.
 	//
-	tlbia, tlbie, tlbsync,
+
+	/// Translation lookaside buffer invalidate all.
+	/// tlbia
+	tlbia,
+
+	/// Translation lookaside buffer invalidate entry.
+	/// tlbie
+	/// rB()
+	tlbie,
+
+	/// Translation lookaside buffer synchronise.
+	/// tlbsync
+	tlbsync,
 
 	//
 	// MARK: - Optional.
@@ -1155,6 +1216,12 @@ struct Instruction {
 	uint32_t l() const	{	return opcode & 0x200000;	}
 	/// Enables setting of OV and SO in the XER; @c 0 or @c non-0.
 	uint32_t oe() const	{	return opcode & 0x400;		}
+
+
+	/// Identifies a special purpose register.
+	uint32_t spr() const 	{	return (opcode >> 11) & 0x3ff;		}
+	/// Identifies a time base register.
+	uint32_t tbr() const 	{	return (opcode >> 11) & 0x3ff;		}
 };
 
 // Sanity check on Instruction size.
diff --git a/OSBindings/Mac/Clock SignalTests/DingusdevPowerPCTests.mm b/OSBindings/Mac/Clock SignalTests/DingusdevPowerPCTests.mm
index f1450ad0c..1452b3dee 100644
--- a/OSBindings/Mac/Clock SignalTests/DingusdevPowerPCTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/DingusdevPowerPCTests.mm	
@@ -315,6 +315,33 @@ NSString *offset(Instruction instruction) {
 				XCTAssertEqualObjects(columns[3], conditionreg(instruction.crfD()));
 			break;
 
+			case Operation::mffsx:
+				AssertEqualOperationNameE(operation, @"mffsx", instruction);
+				AssertEqualFR(columns[3], instruction.frD());
+			break;
+
+			case Operation::mtmsr:
+				AssertEqualOperationName(operation, @"mtmsr");
+				AssertEqualR(columns[3], instruction.rS());
+			break;
+
+			case Operation::mtsrin:
+				AssertEqualOperationName(operation, @"mtsrin");
+				AssertEqualR(columns[3], instruction.rD());
+				AssertEqualR(columns[4], instruction.rB());
+			break;
+
+			case Operation::mtsr:
+				AssertEqualOperationName(operation, @"mtsr");
+				XCTAssertEqual([columns[3] intValue], instruction.sr());
+				AssertEqualR(columns[4], instruction.rS());
+			break;
+
+			case Operation::tlbie:
+				AssertEqualOperationName(operation, @"tlbie");
+				AssertEqualR(columns[3], instruction.rB());
+			break;
+
 			case Operation::icbi:
 				AssertEqualOperationName(operation, @"icbi");
 				AssertEqualR(columns[3], instruction.rA(), false);
@@ -398,12 +425,24 @@ NSString *offset(Instruction instruction) {
 				AssertEqualOperationName(operation, @#x);	\
 			break;
 
-				NoArg(isync);
-				NoArg(sync);
-				NoArg(eieio);
+			NoArg(isync);
+			NoArg(sync);
+			NoArg(eieio);
+			NoArg(tlbia);
 
 #undef NoArg
 
+#define D(x)	\
+			case Operation::x:	\
+				AssertEqualOperationName(operation, @#x);	\
+				AssertEqualR(columns[3], instruction.rD());	\
+			break;
+
+			D(mfcr);
+			D(mfmsr);
+
+#undef D
+
 #define Shift(x)	\
 			case Operation::x:	\
 				AssertEqualOperationNameE(operation, @#x, instruction);	\
@@ -412,9 +451,9 @@ NSString *offset(Instruction instruction) {
 				AssertEqualR(columns[5], instruction.rB());				\
 			break;
 
-				Shift(slwx);
-				Shift(srwx);
-				Shift(srawx);
+			Shift(slwx);
+			Shift(srwx);
+			Shift(srawx);
 
 #undef Shift
 
@@ -500,21 +539,13 @@ NSString *offset(Instruction instruction) {
 			ABCz(lwzux);
 			ABCz(lbzx);
 			ABCz(lbzux);
-			ABCz(stwx);
-			ABCz(stwux);
-			ABCz(stbx);
-			ABCz(stbux);
 			ABCz(lhzx);
 			ABCz(lhzux);
 			ABCz(lhax);
 			ABCz(lhaux);
-			ABCz(sthx);
-			ABCz(sthux);
 			ABCz(lhbrx);
 			ABCz(lwbrx);
 			ABCz(lwarx);
-			ABCz(stwbrx);
-			ABCz(sthbrx);
 			ABCz(eciwx);
 			ABCz(lswx);
 			ABCz(lwa);
@@ -582,7 +613,20 @@ NSString *offset(Instruction instruction) {
 				AssertEqualR(columns[5], instruction.rB());	\
 			break;
 
+			SAB(ecowx);
+			SAB(stbux);
+			SAB(stbx);
+			SAB(sthbrx);
+			SAB(sthux);
+			SAB(sthx);
+			SAB(stswx);
+			SAB(stwbrx);
 			SAB(stwcx_);
+			SAB(stwux);
+			SAB(stwx);
+			SAB(stdcx_);
+			SAB(stdux);
+			SAB(stdx);
 
 #undef SAB