[valgrind] [Bug 406674] False positive when reading bitfield value on code compiled with clang 7.0

[Julian Seward]

https://bugs.kde.org/show_bug.cgi?id=406674

--- Comment #2 from Julian Seward <jsew...@acm.org> ---
Sigh.  Looks like we need yet another spec rule, for this:

  4005e2:       c0 e0 04                shl    $0x4,%al
  4005e5:       74 19                   je     400600 <main+0x30>

I'll try to hack one up later, but if you want to try now, in the
function guest_amd64_spechelper(), find this

      if (isU64(cc_op, AMD64G_CC_OP_SHRL) && isU64(cond, AMD64CondZ)) {
         /* SHRL, then Z --> test dep1 == 0 */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpEQ32, unop(Iop_64to32, cc_dep1),
                           mkU32(0)));
      }

and add an 8-bit version of it (the above example is for shrl; je/jz).

-- 
You are receiving this mail because:
You are watching all bug changes.