| Message ID | 20110603184102.54707571@rex.config |
|---|---|
| State | New |
| Headers | show |
On 06/03/11 18:41, Julian Brown wrote: > On Thu, 02 Jun 2011 16:35:01 +0100 > Richard Earnshaw<rearnsha@arm.com> wrote: > > >> I see Paul has already approved this, but I've just spotted one >> potential problem that might cause latent bugs sometime in the future. >> >> The code to register the libcalls is only run once, the first time we >> try to look up a libcall. If we ever end up allowing dynamic changing >> of CPU and optimization options, not registering the other libcalls >> will lead to subtle problems at run time. I suggest that these >> functions be unconditionally added along with the other libcalls. >> > Done. > > >> I also don't understand why all the tests are needed in >> arm_init_cumulative_args? Surely arm_libcall_uses_aapcs_base() will >> already have run that test. >> > I did some archaeology to try to figure out why things were like that > (the patch was written a while ago) -- and yeah, it looks like it's > completely unnecessary to have those tests in arm_init_cumulative_args. > That bit of code was refactored a while ago, and it looks like the > patch wasn't ever updated properly. My mistake! > > I'm re-testing the attached version. > > Thanks, > > Julian > > ChangeLog > > gcc/ > * config/arm/arm.c (arm_libcall_uses_aapcs_base): Use correct ABI > for double-precision helper functions in hard-float mode if only > single-precision arithmetic is supported in hardware. OK. R.
> > I'm re-testing the attached version. Shouldn't this be backported to release branches - specifically 4.6 (and 4.5 since this is where TARGET_VFP_SINGLE was introduced) ? cheers Ramana
commit 8084eeee248e648e3276b91a957f667c299f84e1
Author: Julian Brown <julian@henry7.codesourcery.com>
Date: Fri Jun 3 04:34:23 2011 -0700
VFP ABI fix for double-precision helpers on single-only processors.
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 057f9ba..a1d009b 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -3345,6 +3345,28 @@ arm_libcall_uses_aapcs_base (const_rtx libcall)
convert_optab_libfunc (sfix_optab, DImode, SFmode));
add_libcall (libcall_htab,
convert_optab_libfunc (ufix_optab, DImode, SFmode));
+
+ /* Values from double-precision helper functions are returned in core
+ registers if the selected core only supports single-precision
+ arithmetic, even if we are using the hard-float ABI. The same is
+ true for single-precision helpers, but we will never be using the
+ hard-float ABI on a CPU which doesn't support single-precision
+ operations in hardware. */
+ add_libcall (libcall_htab, optab_libfunc (add_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (sdiv_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (smul_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (neg_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (sub_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (eq_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (lt_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (le_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (ge_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (gt_optab, DFmode));
+ add_libcall (libcall_htab, optab_libfunc (unord_optab, DFmode));
+ add_libcall (libcall_htab, convert_optab_libfunc (sext_optab, DFmode,
+ SFmode));
+ add_libcall (libcall_htab, convert_optab_libfunc (trunc_optab, SFmode,
+ DFmode));
}
return libcall && htab_find (libcall_htab, libcall) != NULL;