[Bug c/47751] New: Wrong code with -mcpu=8540 -mfloat-gprs=double -mspe -Os on PowerPC

[Bug c/47751] New: Wrong code with -mcpu=8540 -mfloat-gprs=double -mspe -Os on PowerPC

[sebastian.huber@embedded-brains.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47751

           Summary: Wrong code with -mcpu=8540 -mfloat-gprs=double -mspe
                    -Os on PowerPC
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: sebastian.huber@embedded-brains.de
            Target: powerpc-rtems4.11una


Created attachment 23349
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23349
Assembler code.

In the attached assembler file:

Line 371: Save of non-volatile registers via stmw 25,28(1)

Line 454: Restore of non-volatile registers via b _rest64gpr_25_x

This procedure is completely wrong, e.g. _rest64gpr_25_x loads the link
register from a wrong stack position with an arbitrary value.

[Bug c/47751] Wrong code with -mcpu=8540 -mfloat-gprs=double -mspe -Os on PowerPC

[sebastian.huber@embedded-brains.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47751

--- Comment #1 from Sebastian Huber <sebastian.huber@embedded-brains.de> 2011-02-15 13:12:52 UTC ---
Created attachment 23350
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23350
C source code corresponding to the assembler code.

[Bug target/47751] Wrong code with -mcpu=8540 -mfloat-gprs=double -mspe -Os on PowerPC

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47751

--- Comment #2 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2011-02-15 17:51:18 UTC ---
-mfloat-gprs=double or -mspe without -mabi=spe does not correspond to any 
standard ABI variant and is very likely to be broken.

[Bug target/47751] Wrong code with -mcpu=8540 -mfloat-gprs=double -mspe -Os on PowerPC

[sebastian.huber@embedded-brains.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47751

--- Comment #3 from Sebastian Huber <sebastian.huber@embedded-brains.de> 2011-02-22 11:18:29 UTC ---
(In reply to comment #2)
> -mfloat-gprs=double or -mspe without -mabi=spe does not correspond to any 
> standard ABI variant and is very likely to be broken.

Thanks for the hint.  Adding the -mabi=spe option fixed the problem.  A notice
in the -mfloat-gprs description of the documentation would be nice.