[Bug bootstrap/51860] [4.7 regression] s390 esa mode bootstrap comparison failure since transactional memory branch merge

[krebbel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51860

--- Comment #3 from Andreas Krebbel <krebbel at gcc dot gnu.org> 2012-01-15 20:37:02 UTC ---
(In reply to comment #2)
> Reducing a -fcompare-debug failure on c-common.c with delta.

Thanks for working on this! I already had a quick look. The problem has to do
with the s390 reorg pass having to split the literal pool. The jump over the
literal pool is placed differently with and without debug info.

There are several places where we still use NEXT_INSN or INSN_P what will be
affected by DEBUG_INSNs being present. I'll track this down tomorrow.

no debug info:

L33: <bb: 48  size: 14  insns: 5>
        0x4ff9fc  basr    r13, r0                         
        0x4ff9fe  la      r13, 14(r13)                    
        0x4ffa02  basr    r14, r12                        
        0x4ffa04  basr    r14, r11                        
        0x4ffa06  j       L34                             
<bb: 49  size: 2  insns: 1>
        0x4ffa0a  nopr    r7                              
L34: <bb: 50  size: 80  insns: 22>
        0x4ffb60  lhi     r1, 0
        0x4ffb64  icm     r1, 3, 0(r2)  

with debug info:

L33: <bb: 48  size: 18  insns: 6>
        0x4ff9fc  basr    r13, r0                         
        0x4ff9fe  la      r13, 18(r13)                    
        0x4ffa02  basr    r14, r12                        
        0x4ffa04  basr    r14, r11                        
        0x4ffa06  lhi     r1, 0                           
        0x4ffa0a  j       L34                             
<bb: 49  size: 2  insns: 1>
        0x4ffa0e  nopr    r7                              
L34: <bb: 50  size: 76  insns: 21>
        0x4ffb64  icm     r1, 3, 0(r2)