From f9a323d10a9f5da305cbdec632d6bdf7ad4770b5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micha=C5=82=20Muska=C5=82a?= Date: Sat, 26 Aug 2017 15:15:01 +0200 Subject: Optimise equality comparisons * In both loader and compiler, make sure constants are always the second operand - many passes of the compiler assume that's always the case. * In loader rewrite is_eq_exact with same arguments to skip the instruction and with different constants move one to an x register to maintain the properly outlined above. * The same (but in reverse) is done with the is_ne_exact, where we rewrite to an unconditional jump or add a move to an x register. * All of the above allow to replace is_eq_exact_fss with is_eq_exact_fyy and is_ne_exact_fss with is_ne_exact_fSS as those are the only possibilities left. --- erts/emulator/beam/ops.tab | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'erts/emulator/beam') diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab index b6e995fdbe..ba0aa005c9 100644 --- a/erts/emulator/beam/ops.tab +++ b/erts/emulator/beam/ops.tab @@ -413,9 +413,18 @@ send # Optimized comparisons with one immediate/literal operand. # -is_eq_exact Lbl R=xy C=ian => i_is_eq_exact_immed Lbl R C +is_eq_exact Lbl S S => +is_eq_exact Lbl C1=c C2=c => move C1 x | is_eq_exact Lbl x C2 +is_eq_exact Lbl C=c R=xy => is_eq_exact Lbl R C + +is_eq_exact Lbl R=xy n => is_nil Lbl R +is_eq_exact Lbl R=xy C=ia => i_is_eq_exact_immed Lbl R C is_eq_exact Lbl R=xy C=q => i_is_eq_exact_literal Lbl R C +is_ne_exact Lbl S S => jump Lbl +is_ne_exact Lbl C1=c C2=c => move C1 x | is_ne_exact Lbl x C2 +is_ne_exact Lbl C=c R=xy => is_ne_exact Lbl R C + is_ne_exact Lbl R=xy C=ian => i_is_ne_exact_immed Lbl R C is_ne_exact Lbl R=xy C=q => i_is_ne_exact_literal Lbl R C @@ -429,7 +438,9 @@ i_is_ne_exact_literal f xy c is_eq_exact Lbl Y=y X=x => is_eq_exact Lbl X Y is_eq_exact f x xy -is_eq_exact f s s +is_eq_exact f y y + +is_ne_exact f S S is_lt f x x is_lt f x c @@ -445,8 +456,6 @@ is_ge f c x is_ge f s s %hot -is_ne_exact f s s - is_eq f s s is_ne f s s -- cgit v1.2.3