r267081 - in /trunk/gcc: ChangeLog doc/invoke.texi

[ktkachov at gcc dot gnu dot org]

Author: ktkachov
Date: Thu Dec 13 10:37:15 2018
New Revision: 267081

URL: https://gcc.gnu.org/viewcvs?rev=267081&root=gcc&view=rev
Log:
[AArch64][doc] Clarify -msve-vector-bits=128 behaviour

We've received reports about the -msve-vector-bits=128 bits being somewhat ambiguous.
It isn't clear whether -msve-vector-bits=128 forces vector-length-agnostic code or whether
-msve-vector-bits=scalable forces 128-bit vector-lengh-specific code.
The latter is a, perhaps unintuitive, reading that we want to exclude.

This patch makes it more explicit that -msve-vector-bits=128 is special and produces
vector-length *agnostic* code. In the end, I've rewritten the whole option documentation.

Checked make pdf that the output looks reasonable.

    * doc/invoke.texi (-msve-vector-bits): Clarify -msve-vector-bits=128
    behavior.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/doc/invoke.texi