[Bug target/20018] New: [4.0 regression] unable to find a register to spill in class ‘PR_REGS’

["schwab at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

This is another fallout from the simplify-rtx.c change, where the fix for the fix causes another regression:

       * simplify-rtx.c (simplify_relational_operation_1): Avoid creating
       zero extensions of BImode operands.  Call lowpart_subreg instead
       of gen_lowpart_common and gen_lowpart_SUBREG.

$ gcc/xgcc -Wall -B gcc/ -O2 -S ex_getln.i 
ex_getln.i: In function â??getcmdlineâ??:
ex_getln.i:4475: error: unable to find a register to spill in class â??PR_REGSâ??
ex_getln.i:4475: error: this is the insn:
(insn 5728 5721 5730 633 (set (reg:BI 262 p6 [2906])
        (ior:BI (reg:BI 262 p6 [2900])
            (subreg:BI (reg:SI 132 f4 [3004]) 0))) 63 {iorbi3} (insn_list:REG_DEP_TRUE 5721 (nil))
    (expr_list:REG_DEAD (reg:BI 262 p6 [2900])
        (nil)))
ex_getln.i:4475: internal compiler error: in spill_failure, at reload1.c:1872

-- 
           Summary: [4.0 regression] unable to find a register to spill in
                    class â??PR_REGSâ??
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: critical
          Priority: P2
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: schwab at suse dot de
                CC: gcc-bugs at gcc dot gnu dot org,roger at eyesopen dot
                    com
GCC target triplet: ia64-suse-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20018