[Bug rtl-optimization/53533] [4.7/4.8 regression] vectorization causes loop unrolling test slowdown as measured by Adobe's C++Benchmark

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53533

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |stevenb.gcc at gmail dot
                   |                            |com

--- Comment #10 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-06-12 
11:57:20 UTC ---
Changing the insn_and_split to

(define_insn_and_split "*sse2_mulv4si3"
  [(set (match_operand:V4SI 0 "register_operand")
        (mult:V4SI (match_operand:V4SI 1 "register_operand")
                   (match_operand:V4SI 2 "nonmemory_vector_operand")))]
...

and defining

(define_predicate "nonmemory_vector_operand"
    (ior (match_operand 0 "register_operand")
         (match_code "const_vector")))

we ICE because when splitting

(insn 26 24 27 3 (set (reg:V4SI 82 [ vect_var_.10 ])
        (mult:V4SI (reg:V4SI 83 [ MEM[symbol: a, index: ivtmp.20_9, offset: 0B]
])
            (const_vector:V4SI [
                    (const_int 23 [0x17])
                    (const_int 23 [0x17])
                    (const_int 23 [0x17])
                    (const_int 23 [0x17])
                ]))) t.c:9 1496 {*sse2_mulv4si3}
     (expr_list:REG_DEAD (reg:V4SI 83 [ MEM[symbol: a, index: ivtmp.20_9,
offset: 0B] ])
        (nil)))

we don't even try to simplify when emitting the code.

But maybe allowing const_vector in (some of) the define_insn_and_split would
be the way to go ...