[Bug c/12084] New: 3.3.1 emitting strange stack handling code for ARM interrupts

["jamesl at appliedminds dot com" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12084

           Summary: 3.3.1 emitting strange stack handling code for ARM
                    interrupts
           Product: gcc
           Version: 3.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jamesl at appliedminds dot com
                CC: gcc-bugs at gcc dot gnu dot org

The following was compiled with arm-elf-gcc -S -g -O2 -Wall -mcpu=arm7tdmi




void int_handler(void) __attribute__((interrupt("IRQ")));




void foo(void)


{


}




void int_handler(void)


{


    foo();


}




It emitted this assembly for int_handler:


int_handler:


.LFB5:


    .loc 1 8 0


    @ Interrupt Service Routine.


    @ args = 0, pretend = 0, frame = 0


    @ frame_needed = 1, uses_anonymous_args = 0


    str ip, [sp, #-4]!


    mov ip, sp


.LCFI0:


    stmfd   sp!, {r0, r1, r2, r3, fp, ip, lr, pc}


.LCFI1:


    sub fp, ip, #4


.LCFI2:


    .loc 1 9 0


    bl  foo


    ldmea   fp, {r0, r1, r2, r3, fp, sp, lr}


    ldmfd   sp!, {ip}


    subs    pc, lr, #4




1) The stack pointer is not being reset to its original location.


2) One of those ldm** needs a ^ after it to restore the correct CPSR.




This seems to be the same bug as in 3.2