Commit 91054846 authored by Anton Ertl's avatar Anton Ertl
Browse files

optimize /MODF U/MOD; test division optimization

parent a31033d8

fold.fs

+17 −0
Original line number Diff line number Diff line
@@ -202,3 +202,20 @@ optimizes fpick 
' opt-modf optimizes umod

\ does not optimize MIN-N UMOD; add another optimizer if you want that.



: opt-/modf ( xt -- )

    lits# 1 = if

	lits> dup 0> over pow2? and if

	    dup 1- ]] dup literal and [[ ctz ]] swap literal arshift [[

	    drop exit then

	>lits then

    fold2-2 ;

' opt-/modf optimizes /modf



: opt-u/mod ( xt -- )

    lits# 1 = if

	lits> dup pow2? if

	    dup 1- ]] dup literal and [[ ctz ]] swap literal rshift [[

	    drop exit then

	>lits then

    fold2-2 ;

' opt-u/mod optimizes u/mod

peeprules.vmg

+3 −0
Original line number Diff line number Diff line
@@ -60,6 +60,9 @@ super33 = noop flit 
super34 = lit+ @

super35 = f@ f*

super36 = f@ f+

super37 = lit and

super38 = lit arshift

super39 = dup lit and swap



\ compare-and-branch; comment them out if we take up work on gforth-native again

cb1 = 0< ?branch

test/gforth.fs

+9 −0
Original line number Diff line number Diff line
@@ -409,3 +409,12 @@ t{ 2 5 -7 */mod -> -4 -2 }t 
t{ -2 5 -7 */mod  -> -3  1 }t



t{ -2 15 -1 u*/mod -> -16 14 }t



\ optimization of division words



t{ :noname -21 4 /f    ; execute -> -6 }t

t{ :noname -21 4 modf  ; execute ->  3 }t

t{ :noname -21 4 /modf ; execute ->  3 -6 }t

t{ :noname  25 4 u/    ; execute ->  6 }t

t{ :noname  25 4 umod  ; execute ->  1 }t

t{ :noname  25 4 u/mod ; execute ->  1 6 }t