Hi guys,
I am trying to compile some files using clang + llvm and I am
encountering the following error during the linking step:
<inline asm>:1:2: error: ambiguous instructions require an explicit
suffix (could be 'btsw', 'btsl', or 'btsq')
bts $14,(%eax)
Which basically does not make any sense, because I don't have the
mentioned inline assembly in any of the C files, and furthermore even
if I did, that is completely valid inline assembly (BTS as per x86
assembly reference does not need w,l or q modifiers)
N.B.:
The command that triggers the error is something along the lines of:
ld.gold -plugin LLVMgold.so -m elf_i386 -r -o final.o part1.o part2.o
@char:~/workspace$ clang -v
clang version 3.3.1
Target: x86_64-unknown-linux-gnu
Thread model: posix
@char:~/workspace$ ld.gold -v
GNU gold (Linux/GNU Binutils 2.24.51.0.1.20131106) 1.11
--
Sincerely,
Razvan Ghitulete
On Nov 20, 2013, at 10:04 AM, Ghitulete Razvan <razvan.ghitulete at gmail.com> wrote:> <inline asm>:1:2: error: ambiguous instructions require an explicit > suffix (could be 'btsw', 'btsl', or 'btsq') > bts $14,(%eax)This has come up before <https://groups.google.com/forum/#!topic/llvm-dev/vomnIQjefzA>. I don't recall if there was a resolution. -- Stephen Checkoway
On Wed, Nov 20, 2013 at 8:55 PM, Stephen Checkoway <s at pahtak.org> wrote:> > This has come up before <https://groups.google.com/forum/#!topic/llvm-dev/vomnIQjefzA>. I don't recall if there was a resolution. >Thanks for the link, completely missed when googled the issue. I think no consensus was reached (I cannot find any commit in the repository addressing such issues). I will try and search for the culprit of the inline assembly and replace it with btsl. As for the issue at hand, although after carefully reading both the thread and re-reading the sections from the instructions set reference it is a rather unpleasant behavior, the error thrown by the toolchain. Since Intel is nowadays by far the biggest vendor for x86/x86_64 hardware and they do not mention a single thing about the existence of suffixes for this instruction, it could be accommodated (maybe with a warning though) and take the second option from the 3 you provided. P.S. : after searching a bit more, it seems that llvm is in fact the only toolchain that rejects/complains about the bts ambiguity, or at least people using llvm get annoyed more easily and start spamming mailing lists :). -- Sincerely, Razvan Ghitulete