+static unsigned int branchTargetOperand(MachineInstr *MI) {
+ switch (MI->getOpcode()) {
+ case Mips::Bimm16:
+ case Mips::BimmX16:
+ case Mips::Bteqz16:
+ case Mips::BteqzX16:
+ case Mips::Btnez16:
+ case Mips::BtnezX16:
+ case Mips::JalB16:
+ return 0;
+ case Mips::BeqzRxImm16:
+ case Mips::BeqzRxImmX16:
+ case Mips::BnezRxImm16:
+ case Mips::BnezRxImmX16:
+ return 1;
+ }
+ llvm_unreachable("Unknown branch type");
+}
+
+static bool isUnconditionalBranch(unsigned int Opcode) {
+ switch (Opcode) {
+ default: return false;
+ case Mips::Bimm16:
+ case Mips::BimmX16:
+ case Mips::JalB16:
+ return true;
+ }
+}
+
+static unsigned int longformBranchOpcode(unsigned int Opcode) {
+ switch (Opcode) {
+ case Mips::Bimm16:
+ case Mips::BimmX16:
+ return Mips::BimmX16;
+ case Mips::Bteqz16:
+ case Mips::BteqzX16:
+ return Mips::BteqzX16;
+ case Mips::Btnez16:
+ case Mips::BtnezX16:
+ return Mips::BtnezX16;
+ case Mips::JalB16:
+ return Mips::JalB16;
+ case Mips::BeqzRxImm16:
+ case Mips::BeqzRxImmX16:
+ return Mips::BeqzRxImmX16;
+ case Mips::BnezRxImm16:
+ case Mips::BnezRxImmX16:
+ return Mips::BnezRxImmX16;
+ }
+ llvm_unreachable("Unknown branch type");
+}
+
+//
+// FIXME: need to go through this whole constant islands port and check the math
+// for branch ranges and clean this up and make some functions to calculate things
+// that are done many times identically.
+// Need to refactor some of the code to call this routine.
+//
+static unsigned int branchMaxOffsets(unsigned int Opcode) {
+ unsigned Bits, Scale;
+ switch (Opcode) {
+ case Mips::Bimm16:
+ Bits = 11;
+ Scale = 2;
+ break;
+ case Mips::BimmX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ case Mips::BeqzRxImm16:
+ Bits = 8;
+ Scale = 2;
+ break;
+ case Mips::BeqzRxImmX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ case Mips::BnezRxImm16:
+ Bits = 8;
+ Scale = 2;
+ break;
+ case Mips::BnezRxImmX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ case Mips::Bteqz16:
+ Bits = 8;
+ Scale = 2;
+ break;
+ case Mips::BteqzX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ case Mips::Btnez16:
+ Bits = 8;
+ Scale = 2;
+ break;
+ case Mips::BtnezX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ default:
+ llvm_unreachable("Unknown branch type");
+ }
+ unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale;
+ return MaxOffs;
+}