The compiler options for -mmmx, -msse, etc, serve two purposes:
1. They allow the programmer to use the compiler built-ins for easily
writing MMX/SSE code.
2. They allow the compiler to use MMX/SSE instructions in generated code.
However, the documentation does not explicitly state the second point, only
the first. This had caused much confusion in the development community, as
programmers using the MMX/SSE intrinsics often use runtime CPU detection.
The attached patch updates the documentation to be more explicit about the
effect of these options.
--
Summary: Misleading documentation for -mmmx/msse/...
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: billy dot biggs at gmail dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23809
