Revert "tcg/i386: Rely on undefined/undocumented behaviour of BSF/BSR"
commit9bf38308f603680ca9b8d9a71e954d4c8a982d0c
authorRichard Henderson <rth@twiddle.net>
Tue, 17 Jan 2017 19:38:22 +0000 (17 11:38 -0800)
committerRichard Henderson <rth@twiddle.net>
Tue, 17 Jan 2017 19:59:13 +0000 (17 11:59 -0800)
tree1d6bf5bc6f1b280dc54b6003f1203c46d8c4ab0c
parent23eb9e6b6d5315171cc15969bbc755f258004df0
Revert "tcg/i386: Rely on undefined/undocumented behaviour of BSF/BSR"

This reverts commit 4ac76910734209dab83ddd3795f08fc7889ef463.

This fixes
  http://lists.nongnu.org/archive/html/qemu-devel/2017-01/msg03062.html

While I think we could get away with relying on the undocumented
behaviour, the tcg constraint system isn't powerful enough to
properly describe the required (non-)overlap conditions.

Reported-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
tcg/i386/tcg-target.inc.c