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[Bug rtl-optimization/53533] [4.7/4.8 regression] vectorization causes loop unrolling test slowdown as measured by Adobe's C++Benchmark
- From: "rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 12 Jun 2012 11:57:20 +0000
- Subject: [Bug rtl-optimization/53533] [4.7/4.8 regression] vectorization causes loop unrolling test slowdown as measured by Adobe's C++Benchmark
- Auto-submitted: auto-generated
- References: <bug-53533-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53533
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
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 ...