[Bug c/25428] New: arm-elf-gcc generating wrong code with -O flag at functions with __attribute__ ((interrupt ("IRQ")))

[th dot r dot klein at web dot de]

If a little bit more complex interrupt function is required the compiler
genrates wrong code (olny with -O flag set).

Compiler generats:
        sub     lr, lr, #4
        stmfd   sp!, {r.., lr}
        .
        .
        .
        ldmfd   sp!, {r.., lr}
        subs    pc, lr, #4

Here the LR is decremented one time too mutch.
Ether first or the second "sub" is wrong.
It should be:
        sub     lr, lr, #4
        stmfd   sp!, {r.., lr}
        .
        .
        .
        ldmfd   sp!, {r.., lr}^

(the last '^' is important)

P.S. Since I can't add any attachments now. I'll try this after 'commit'.


-- 
           Summary: arm-elf-gcc generating wrong code with -O flag at
                    functions with __attribute__ ((interrupt ("IRQ")))
           Product: gcc
           Version: 4.0.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: th dot r dot klein at web dot de
  GCC host triplet: i386-freebds-elf
GCC target triplet: arm-unknown-elf


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25428