[Bug rtl-optimization/45223] New: RTL PRE GCSE pass hoists trapping insn out of loop

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

This is a follow-up from PR38819 which partially fixes this problem. The
problem remains in RTL optimization passes, and can be triggered on targets
that implement modulo instruction in the hardware (i.e. moxie-elf).

The testcase from PR38819 compiles with -O2 to:

main:
        push   $sp, $r6
        push   $sp, $r7
        push   $sp, $r8
        push   $sp, $r9
        push   $sp, $r10
        push   $sp, $r11
        dec    $sp, 24
        lda.l  $r7, a
        lda.l  $r0, b
        xor    $r6, $r6
        ldi.l  $r11, foo
>	mod.l  $r7, $r0
        ldi.l  $r10, 8
        ldi.l  $r8, 99
        jmpa   .L4
.L3:
        ...

Since b is initialized to zero, mod.l instruction traps.


-- 
           Summary: RTL PRE GCSE pass hoists trapping insn out of loop
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ubizjak at gmail dot com
GCC target triplet: moxie-elf


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45223