[LLVMbugs] [Bug 17539] New: mips disassembly does not sign-extend immediate operand (daddiu, others?)

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=17539

            Bug ID: 17539
           Summary: mips disassembly does not sign-extend immediate
                    operand (daddiu, others?)
           Product: new-bugs
           Version: trunk
          Hardware: PC
                OS: FreeBSD
            Status: NEW
          Severity: normal
          Priority: P
         Component: new bugs
          Assignee: unassignedbugs at nondot.org
          Reporter: emaste at freebsd.org
                CC: llvmbugs at cs.uiuc.edu
    Classification: Unclassified

I'm adding MIPS support to LLDB and see that daddiu's 16-bit immediate operand
is not interpreted properly:

(lldb) disass
libc.so.7`__raise:
   0x16019e8e0:  daddiu $sp, $sp, 65504
   0x16019e8e4:  sd     $ra, 16($sp)
...

it is a 16-bit signed value; 65504 should be -32

Mips64InstrInfo.td
def DADDiu  : ArithLogicI<"daddiu", simm16_64, GPR64Opnd, IIArith,              
                          immSExt16, add>,                                      
              ADDI_FM<0x19>, IsAsCheapAsAMove;                                  

MipsGenDisassemblerTables.inc
  case 159:
    tmp = fieldFromInstruction(insn, 16, 5);
    if (DecodeGPR64RegisterClass(MI, tmp, Address, Decoder) ==
MCDisassembler::Fail) return MCDisassembler::Fail;
    tmp = fieldFromInstruction(insn, 21, 5);
    if (DecodeGPR64RegisterClass(MI, tmp, Address, Decoder) ==
MCDisassembler::Fail) return MCDisassembler::Fail;
    tmp = fieldFromInstruction(insn, 0, 16);
    MI.addOperand(MCOperand::CreateImm(tmp));
    return S;

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20131010/6bd1d5e0/attachment.html>