Ramana Radhakrishnan <ramana....@googlemail.com> writes: > On Thu, Dec 13, 2018 at 10:15 AM Richard Sandiford > <richard.sandif...@arm.com> wrote: >> >> Thanks for doing this. >> >> "Kyrill Tkachov" <kyrylo.tkac...@foss.arm.com> writes: >> > @@ -15716,16 +15716,19 @@ an effect when SVE is enabled. >> > >> > GCC supports two forms of SVE code generation: ``vector-length >> > agnostic'' output that works with any size of vector register and >> > -``vector-length specific'' output that only works when the vector >> > -registers are a particular size. Replacing @var{bits} with >> > -@samp{scalable} selects vector-length agnostic output while >> > -replacing it with a number selects vector-length specific output. >> > -The possible lengths in the latter case are: 128, 256, 512, 1024 >> > -and 2048. @samp{scalable} is the default. >> > - >> > -At present, @samp{-msve-vector-bits=128} produces the same output >> > -as @samp{-msve-vector-bits=scalable}. >> > - >> > +``vector-length specific'' output that allows GCC to make assumptions >> > +about the vector length when it is useful for optimization reasons. >> > +The possible values of @samp{bits} are: @samp{scalable}, @samp{128}, >> > +@samp{256}, @samp{512}, @samp{1024} and @samp{2048}. >> > +Specifying @samp{scalable} selects vector-length agnostic >> > +output. At present @samp{-msve-vector-bits=128} also generates >> > vector-length >> > +agnostic output. All other values generate vector-length specific code. >> > +The behavior of these values may change in future releases and no value >> > except >> > +@samp{scalable} should be relied on for producing code that is portable >> > across >> > +different hardware SVE vector lengths. >> > + >> > +The default is @samp{-msve-vector-bits=scalable} which produces >> > +vector-length agnostic code. >> >> Think we should have a comma before "which" in the last sentence. >> OK with that change. > > And backport to GCC-8 ?
Yeah, OK for the backport too.