[Bug rtl-optimization/53487] New: [4.8 Regression] Unrecognizable insn for conditional move

["wschmidt at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53487

             Bug #: 53487
           Summary: [4.8 Regression] Unrecognizable insn for conditional
                    move
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: wschmidt@gcc.gnu.org
                CC: bergner@gcc.gnu.org, meissner@gcc.gnu.org,
                    pinskia@gcc.gnu.org
              Host: powerpc64-linux
            Target: powerpc64-linux
             Build: powerpc64-linux


Created attachment 27496
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27496
Reduced testcase

The attached test (reduced from 456.hmmer) fails to compile beginning with
r187183, as shown:

wschmidt@bns:~/delta> gcc -c -o cluster.o  -m64 -O3 -mcpu=power7 -ffast-math
-misel cluster.i
cluster.i: In function ‘Cluster’:
cluster.i:30:1: error: unrecognizable insn:
 }
 ^
(insn 156 155 157 8 (set (reg:SI 289)
        (if_then_else:SI (ge (reg:SF 291)
                (const_double:SF 0.0 [0x0.0p+0]))
            (subreg/s:SI (reg/v:DI 258 [ i+-4 ]) 4)
            (subreg/s:SI (reg/v:DI 265 [ row+-4 ]) 4))) -1
     (nil))
cluster.i:30:1: internal compiler error: in extract_insn, at recog.c:2130
 }
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

This form of conditional move insn isn't recognized on powerpc64 because the
floating-point comparison is incompatible with a conditional move of integer
arguments.  Prior to this revision, code generation recognized the
incompatibility and did not generate the conditional move.

r187183 is:

2012-05-04  Andrew Pinski  <apinski@cavium.com>

    * expr.c (get_def_for_expr_class): New function.
    (convert_tree_comp_to_rtx): New function.
    (expand_cond_expr_using_cmove): New function.
    (expand_expr_real_2 <case COND_EXPR>): Call
    expand_cond_expr_using_cmove first and return if it succeeds.
    Remove the check for HAVE_conditional_move since we should have
    already converted it to a conditional move.
    * config/i386/i386.c (ix86_expand_int_movcc): Disallow comparison
    modes of DImode for 32bits and TImode.