[ARM] Resurrect VxWorks port

[Eric Botcazou]

Hi,

as diagnosed by Doug, the VxWorks port cannot be built since:

2011-05-18  Joseph Myers  <jos...@codesourcery.com>

which reorganized the ARM options and turned arm_fp16_format from a global 
variable defined in arm.c into an option variable, leading to:

In file included from ../../.././gcc/tm.h:20:0,
                 from /home/eric/svn/gcc/libgcc/fp-bit.c:38:
/home/eric/svn/gcc/libgcc/fp-bit.c: In function '__pack_f':
/home/eric/svn/gcc/libgcc/../gcc/config/arm/arm.h:426:22: error: 
'arm_fp16_format' undeclared (first use in this function)
     ((bits) == 16 && arm_fp16_format == ARM_FP16_FORMAT_ALTERNATIVE)
                      ^
/home/eric/svn/gcc/libgcc/fp-bit.c:205:7: note: in expansion of macro 
'LARGEST_EXPONENT_IS_NORMAL'
   if (LARGEST_EXPONENT_IS_NORMAL (FRAC_NBITS) && (isnan (src) || isinf 
(src)))
       ^
/home/eric/svn/gcc/libgcc/../gcc/config/arm/arm.h:426:22: note: each 
undeclared identifier is reported only once for each function it appears in
     ((bits) == 16 && arm_fp16_format == ARM_FP16_FORMAT_ALTERNATIVE)
                      ^
/home/eric/svn/gcc/libgcc/fp-bit.c:205:7: note: in expansion of macro 
'LARGEST_EXPONENT_IS_NORMAL'
   if (LARGEST_EXPONENT_IS_NORMAL (FRAC_NBITS) && (isnan (src) || isinf 
(src)))
       ^
make[3]: *** [_pack_sf.o] Error 1

Because fp-bit.c references macro
LARGEST_EXPONENT_IS_NORMAL (FRAC_NBITS)
which is defined in arm.h and references arm_fp16_format
which in turn is now a macro defined in options.h:
#define arm_fp16_format global_options.x_arm_fp16_format.

Furthermore

2011-08-05  Rainer Orth  <r...@cebitec.uni-bielefeld.de>

moved fp-bit.c into libgcc, making it more convoluted to fix it.

So we are proposing to switch the VxWorks port over to the soft-fp emulation 
instead of the fp-bit one, like most of the other ARM ports.

Tested on ARM/VxWorks, OK for all active branches (they are all broken)?


2013-05-31  Douglas B Rupp  <r...@adacore.com>

        * config.host (arm-wrs-vxworks): Configure with other soft float.


-- 
Eric Botcazou
Index: config.host
===================================================================
--- config.host	(revision 199343)
+++ config.host	(working copy)
@@ -316,7 +316,7 @@ alpha*-dec-*vms*)
 	md_unwind_header=alpha/vms-unwind.h
 	;;
 arm-wrs-vxworks)
-	tmake_file="$tmake_file arm/t-arm arm/t-vxworks t-fdpbit"
+	tmake_file="$tmake_file arm/t-arm arm/t-vxworks t-softfp-sfdf t-softfp-excl arm/t-softfp t-softfp"
 	extra_parts="$extra_parts crti.o crtn.o"
 	;;
 arm*-*-netbsdelf*)