From 7effd4c9efc42d7afcef6390d18617e7e97275e6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 21 Apr 2015 08:09:22 +0200 Subject: beam_validator: Correct merging of y registers When merging y registers, only the y registers that are found in both states should be retained. --- lib/compiler/src/beam_validator.erl | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) (limited to 'lib') diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl index c55919dc73..ed94880d38 100644 --- a/lib/compiler/src/beam_validator.erl +++ b/lib/compiler/src/beam_validator.erl @@ -1398,20 +1398,24 @@ merge_regs_1([], [_|_]) -> []; merge_regs_1([_|_], []) -> []. merge_y_regs(Rs0, Rs1) -> - Rs = merge_y_regs_1(gb_trees:to_list(Rs0), gb_trees:to_list(Rs1)), - gb_trees_from_list(Rs). + case {gb_trees:size(Rs0),gb_trees:size(Rs1)} of + {Sz0,Sz1} when Sz0 < Sz1 -> + merge_y_regs_1(Sz0-1, Rs1, Rs0); + {_,Sz1} -> + merge_y_regs_1(Sz1-1, Rs0, Rs1) + end. -merge_y_regs_1([Same|Rs1], [Same|Rs2]) -> - [Same|merge_y_regs_1(Rs1, Rs2)]; -merge_y_regs_1([{R1,_}|Rs1], [{R2,_}|_]=Rs2) when R1 < R2 -> - [{R1,uninitialized}|merge_y_regs_1(Rs1, Rs2)]; -merge_y_regs_1([{R1,_}|_]=Rs1, [{R2,_}|Rs2]) when R1 > R2 -> - [{R2,uninitialized}|merge_y_regs_1(Rs1, Rs2)]; -merge_y_regs_1([{R,Type1}|Rs1], [{R,Type2}|Rs2]) -> - [{R,merge_types(Type1, Type2)}|merge_y_regs_1(Rs1, Rs2)]; -merge_y_regs_1([], []) -> []; -merge_y_regs_1([], [_|_]=Rs) -> Rs; -merge_y_regs_1([_|_]=Rs, []) -> Rs. +merge_y_regs_1(Y, S, Regs0) when Y >= 0 -> + Type0 = gb_trees:get(Y, Regs0), + case gb_trees:get(Y, S) of + Type0 -> + merge_y_regs_1(Y-1, S, Regs0); + Type1 -> + Type = merge_types(Type0, Type1), + Regs = gb_trees:update(Y, Type, Regs0), + merge_y_regs_1(Y-1, S, Regs) + end; +merge_y_regs_1(_, _, Regs) -> Regs. %% merge_types(Type1, Type2) -> Type %% Return the most specific type possible. -- cgit v1.2.3