Re: [Xen-devel] [PATCH v2] x86emul: simplify asm() constraints

2015-03-12 Thread Andrew Cooper
On 12/03/15 13:13, Jan Beulich wrote: > Use + on outputs instead of = and a matching input. Allow not just > memory for the _eflags operand (it turns out that recent gcc produces > worse code when also doing this for _dst.val, so the latter is being > avoided). > > Signed-off-by: Jan Beulich Revi

Re: [Xen-devel] [PATCH v2] x86emul: simplify asm() constraints

2015-03-12 Thread Tim Deegan
At 13:13 + on 12 Mar (1426162439), Jan Beulich wrote: > Use + on outputs instead of = and a matching input. Allow not just > memory for the _eflags operand (it turns out that recent gcc produces > worse code when also doing this for _dst.val, so the latter is being > avoided). > > Signed-off-b

[Xen-devel] [PATCH v2] x86emul: simplify asm() constraints

2015-03-12 Thread Jan Beulich
Use + on outputs instead of = and a matching input. Allow not just memory for the _eflags operand (it turns out that recent gcc produces worse code when also doing this for _dst.val, so the latter is being avoided). Signed-off-by: Jan Beulich --- v2: Extend simplification in {,i}mul_dbl(), as sug