ASM with other compilers

Torbjorn Granlund tg at
Mon Mar 7 21:21:02 CET 2011

Marc Glisse <marc.glisse at> writes:

  currently, clang refuses to compile jb,pt (x86_64/mod_34lsub1.asm) (it
  understands jb without ,pt)

Does "clang" come with its own assembler?

(I am not sure any x86 processor actually uses pt/pn.)

  and Oracle refuses movzb
  (x86_64/gcd_1.asm) (it knows the ...w and ...l versions though).

Does Oracle accept 'movzbl'?
  Are those horrible bugs that should absolutely be reported to the
  compiler vendors, or are there more portable versions of the

We should check the critical processors (K8, K10, Core2, NHM, SBR) for
any slowdowns wrt removing ',pt'.  The insn itself might not be
affected, but the alignment on subsequent instructions might result in
unexpected slowdowns.


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