[PATCH, committed] xl-compat documentation

[David Edelsohn]

	I was alerted that the documentation for -mxl-compat did not
mention long double conversion and long double support routine names.
This patch extends the documentation to list all of the effects of the
option.

David


	* doc/invoke.texi (xl-compat): Document conversion and support
	routine names.

Index: invoke.texi
===================================================================
*** invoke.texi	(revision 110704)
--- invoke.texi	(working copy)
*************** implies @option{-mno-powerpc64}.  GCC de
*** 11247,11266 ****
  @itemx -mno-xl-compat
  @opindex mxl-compat
  @opindex mno-xl-compat
! Produce code that conforms more closely to IBM XLC semantics when using
! AIX-compatible ABI.  Pass floating-point arguments to prototyped
! functions beyond the register save area (RSA) on the stack in addition
! to argument FPRs.  Do not assume that most significant double in 128
! bit long double value is properly rounded when comparing values.
  
  The AIX calling convention was extended but not initially documented to
  handle an obscure K&R C case of calling a function that takes the
! address of its arguments with fewer arguments than declared.  AIX XL
  compilers access floating point arguments which do not fit in the
  RSA from the stack when a subroutine is compiled without
  optimization.  Because always storing floating-point arguments on the
  stack is inefficient and rarely needed, this option is not enabled by
! default and only is necessary when calling subroutines compiled by AIX
  XL compilers without optimization.
  
  @item -mpe
--- 11247,11268 ----
  @itemx -mno-xl-compat
  @opindex mxl-compat
  @opindex mno-xl-compat
! Produce code that conforms more closely to IBM XL compiler semantics
! when using AIX-compatible ABI.  Pass floating-point arguments to
! prototyped functions beyond the register save area (RSA) on the stack
! in addition to argument FPRs.  Do not assume that most significant
! double in 128-bit long double value is properly rounded when comparing
! values and converting to double.  Use XL symbol names for long double
! support routines.
  
  The AIX calling convention was extended but not initially documented to
  handle an obscure K&R C case of calling a function that takes the
! address of its arguments with fewer arguments than declared.  IBM XL
  compilers access floating point arguments which do not fit in the
  RSA from the stack when a subroutine is compiled without
  optimization.  Because always storing floating-point arguments on the
  stack is inefficient and rarely needed, this option is not enabled by
! default and only is necessary when calling subroutines compiled by IBM
  XL compilers without optimization.
  
  @item -mpe