factor/basis/compiler/cfg/value-numbering/simplify/simplify.factor

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Factor

! Copyright (C) 2008 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel accessors combinators classes math layouts
compiler.cfg.instructions
compiler.cfg.value-numbering.graph
compiler.cfg.value-numbering.expressions locals ;
IN: compiler.cfg.value-numbering.simplify
! Return value of f means we didn't simplify.
GENERIC: simplify* ( expr -- vn/expr/f )
: simplify-unbox-alien ( in -- vn/expr/f )
dup op>> \ ##box-alien eq? [ in>> ] [ drop f ] if ; inline
M: unary-expr simplify*
#! Note the copy propagation: a copy always simplifies to
#! its source VN.
[ in>> vn>expr ] [ op>> ] bi {
{ \ ##copy [ ] }
{ \ ##unbox-alien [ simplify-unbox-alien ] }
{ \ ##unbox-any-c-ptr [ simplify-unbox-alien ] }
[ 2drop f ]
} case ;
: expr-zero? ( expr -- ? ) T{ constant-expr f f 0 } = ; inline
: expr-one? ( expr -- ? ) T{ constant-expr f f 1 } = ; inline
: >binary-expr< ( expr -- in1 in2 )
[ in1>> vn>expr ] [ in2>> vn>expr ] bi ; inline
: simplify-add ( expr -- vn/expr/f )
>binary-expr< {
{ [ over expr-zero? ] [ nip ] }
{ [ dup expr-zero? ] [ drop ] }
[ 2drop f ]
} cond ; inline
: simplify-sub ( expr -- vn/expr/f )
>binary-expr< {
{ [ dup expr-zero? ] [ drop ] }
[ 2drop f ]
} cond ; inline
: simplify-mul ( expr -- vn/expr/f )
>binary-expr< {
{ [ over expr-one? ] [ drop ] }
{ [ dup expr-one? ] [ drop ] }
[ 2drop f ]
} cond ; inline
: simplify-and ( expr -- vn/expr/f )
>binary-expr< {
{ [ 2dup eq? ] [ drop ] }
[ 2drop f ]
} cond ; inline
: simplify-or ( expr -- vn/expr/f )
>binary-expr< {
{ [ 2dup eq? ] [ drop ] }
{ [ over expr-zero? ] [ nip ] }
{ [ dup expr-zero? ] [ drop ] }
[ 2drop f ]
} cond ; inline
: simplify-xor ( expr -- vn/expr/f )
>binary-expr< {
{ [ over expr-zero? ] [ nip ] }
{ [ dup expr-zero? ] [ drop ] }
[ 2drop f ]
} cond ; inline
: useless-shr? ( in1 in2 -- ? )
over op>> \ ##shl-imm eq?
[ [ in2>> ] [ expr>vn ] bi* = ] [ 2drop f ] if ; inline
: simplify-shr ( expr -- vn/expr/f )
>binary-expr< {
{ [ 2dup useless-shr? ] [ drop in1>> ] }
{ [ dup expr-zero? ] [ drop ] }
[ 2drop f ]
} cond ; inline
: simplify-shl ( expr -- vn/expr/f )
>binary-expr< {
{ [ dup expr-zero? ] [ drop ] }
[ 2drop f ]
} cond ; inline
M: binary-expr simplify*
dup op>> {
{ \ ##add [ simplify-add ] }
{ \ ##add-imm [ simplify-add ] }
{ \ ##sub [ simplify-sub ] }
{ \ ##sub-imm [ simplify-sub ] }
{ \ ##mul [ simplify-mul ] }
{ \ ##mul-imm [ simplify-mul ] }
{ \ ##and [ simplify-and ] }
{ \ ##and-imm [ simplify-and ] }
{ \ ##or [ simplify-or ] }
{ \ ##or-imm [ simplify-or ] }
{ \ ##xor [ simplify-xor ] }
{ \ ##xor-imm [ simplify-xor ] }
{ \ ##shr [ simplify-shr ] }
{ \ ##shr-imm [ simplify-shr ] }
{ \ ##sar [ simplify-shr ] }
{ \ ##sar-imm [ simplify-shr ] }
{ \ ##shl [ simplify-shl ] }
{ \ ##shl-imm [ simplify-shl ] }
[ 2drop f ]
} case ;
M: expr simplify* drop f ;
: simplify ( expr -- vn )
dup simplify* {
{ [ dup not ] [ drop expr>vn ] }
{ [ dup expr? ] [ expr>vn nip ] }
{ [ dup integer? ] [ nip ] }
} cond ;
: number-values ( insn -- )
[ >expr simplify ] [ dst>> ] bi set-vn ;