static DecodeStatus
DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
uint64_t Address, const void *Decoder) {
- DecodeStatus S = MCDisassembler::Success;
- unsigned imm = (fieldFromInstruction(Insn, 0, 11) << 0) |
- (fieldFromInstruction(Insn, 11, 1) << 18) |
- (fieldFromInstruction(Insn, 13, 1) << 17) |
- (fieldFromInstruction(Insn, 16, 6) << 11) |
- (fieldFromInstruction(Insn, 26, 1) << 19);
- if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<20>(imm<<1) + 4,
+ DecodeStatus Status = MCDisassembler::Success;
+
+ // Note the J1 and J2 values are from the encoded instruction. So here
+ // change them to I1 and I2 values via as documented:
+ // I1 = NOT(J1 EOR S);
+ // I2 = NOT(J2 EOR S);
+ // and build the imm32 with one trailing zero as documented:
+ // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
+ unsigned S = fieldFromInstruction(Insn, 26, 1);
+ unsigned J1 = fieldFromInstruction(Insn, 13, 1);
+ unsigned J2 = fieldFromInstruction(Insn, 11, 1);
+ unsigned I1 = !(J1 ^ S);
+ unsigned I2 = !(J2 ^ S);
+ unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
+ unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
+ unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
+ int imm32 = SignExtend32<24>(tmp << 1);
+ if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
true, 4, Inst, Decoder))
- Inst.addOperand(MCOperand::CreateImm(SignExtend32<20>(imm << 1)));
- return S;
+ Inst.addOperand(MCOperand::CreateImm(imm32));
+
+ return Status;
}
static DecodeStatus
--- /dev/null
+@ RUN: llvm-mc -triple=thumbv7-apple-darwin -mcpu=cortex-a8 -show-encoding < %s | FileCheck %s
+ .syntax unified
+ .globl _func
+.thumb_func _foo
+.space 0x37c6
+_foo:
+@------------------------------------------------------------------------------
+@ B (thumb2 b.w encoding T4) rdar://12585795
+@------------------------------------------------------------------------------
+ b.w 0x3680c
+
+@ CHECK: b.w #223244 @ encoding: [0x6d,0xf0,0x0c,0xb0]