http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57195
Bug #: 57195
Summary: Mode attributes with specific mode iterator can not be
used as mode iterators in *.md files
Classification: Unclassified
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: ubiz...@gmail.com
There is a strange undocumented limitation when using mode attributes with
specific mode iterator as mode iterators in *.md files. As an example from
i386.md, following RTX is accepted:
(define_insn_and_split "copysign<mode>3_const"
[(set (match_operand:CSGNMODE 0 "register_operand" "=x")
(unspec:CSGNMODE
[(match_operand:<CSGNVMODE> 1 "vector_move_operand" "xmC")
(match_operand:CSGNMODE 2 "register_operand" "0")
(match_operand:<CSGNVMODE> 3 "nonimmediate_operand" "xm")]
UNSPEC_COPYSIGN))]
...)
However, when equivalent named mode attribute (i.e. <CSGNMODE:CSGNVMODE> below)
is used in place of a mode iterator:
(define_insn_and_split "copysign<mode>3_const"
[(set (match_operand:CSGNMODE 0 "register_operand" "=x")
(unspec:CSGNMODE
[(match_operand:<CSGNMODE:CSGNVMODE> 1 "vector_move_operand" "xmC")
(match_operand:CSGNMODE 2 "register_operand" "0")
(match_operand:<CSGNVMODE> 3 "nonimmediate_operand" "xm")]
UNSPEC_COPYSIGN))]
...)
compilation breaks with:
build/genconditions
../../gcc-svn/branches/gcc-4_8-branch/gcc/config/i386/i386.md > tmp-condmd.c
../../gcc-svn/branches/gcc-4_8-branch/gcc/config/i386/i386.md:8866: unknown
mode `<CSGNMODE'
../../gcc-svn/branches/gcc-4_8-branch/gcc/config/i386/i386.md:8866: following
context is `:CSGNVMODE> 1 "vector_move_operand" "xmC")'
The iterators are defined as:
(define_mode_iterator CSGNMODE [SF DF TF])
(define_mode_attr CSGNVMODE [(SF "V4SF") (DF "V2DF") (TF "TF")])
I would like to use mode attribute with named mode in the following pattern:
(define_insn "*vec_extract<PEXTR_MODE:mode>_zext"
[(set (match_operand:SWI48 0 "register_operand" "=r")
(zero_extend:SWI48
(vec_select:<PEXTR_MODE:ssescalarmode>
(match_operand:PEXTR_MODE 1 "register_operand" "x")
(parallel
[(match_operand:SI 2
"const_0_to_<PEXTR_MODE:ssescalarnummask>_operand")]))))]
where ssescalarmode mode attribute applies to PEXTR_MODE mode iterator, and not
to SWI48.
