PATCH to invoke.texi: document -fssa

[Alex Samuel]

This patch describes the -fssa optimization flag in the invocation
documentation.

	* invoke.texi: Document -fssa flag.


Index: invoke.texi
===================================================================
RCS file: /cvs/gcc/egcs/gcc/invoke.texi,v
retrieving revision 1.186
diff -c -p -r1.186 invoke.texi
*** invoke.texi	2000/04/24 18:03:42	1.186
--- invoke.texi	2000/04/27 06:47:37
*************** in the following sections.
*** 166,172 ****
  -fno-function-cse  -fno-inline  -fno-peephole
  -fomit-frame-pointer  -foptimize-register-moves -foptimize-sibling-calls
  -fregmove -frerun-cse-after-loop  -frerun-loop-opt  -freduce-all-givs
! -fschedule-insns  -fschedule-insns2  -fstrength-reduce
  -fstrict-aliasing  -fthread-jumps  -funroll-all-loops
  -funroll-loops
  -O  -O0  -O1  -O2  -O3 -Os
--- 166,172 ----
  -fno-function-cse  -fno-inline  -fno-peephole
  -fomit-frame-pointer  -foptimize-register-moves -foptimize-sibling-calls
  -fregmove -frerun-cse-after-loop  -frerun-loop-opt  -freduce-all-givs
! -fschedule-insns  -fschedule-insns2  -fssa -fstrength-reduce
  -fstrict-aliasing  -fthread-jumps  -funroll-all-loops
  -funroll-loops
  -O  -O0  -O1  -O2  -O3 -Os
*************** bytes like @samp{-falign-functions}.  In
*** 2831,2836 ****
--- 2831,2843 ----
  need be executed.
  
  If @var{n} is not specified, use a machine-dependent default.
+ 
+ @item -fssa
+ Perform optimizations in static single assignment form.  Each function's
+ flow graph is translated into SSA form, optimizations are performed, and
+ the flow graph is translated back from SSA form.  (Currently, no
+ SSA-based optimizations are implemented, but converting into and out of
+ SSA form is not an invariant operation, and generated code may differ.)
  
  @end table