From e92ad3c4d6358cecbba7643ccc14610957ad79ab Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Mon, 10 Aug 2015 06:25:00 +0200 Subject: v3_core: Improve code generation for guards When translating guards to Core Erlang, it is sometimes necessary to add an is_boolean/1 guard test. Here is an example when it is necessary: o(A, B) when A or B -> ok. That would be translated to something like: o(A, B) when ((A =:= true) or (B =:= true)) and is_boolean(A) and is_boolean(B) -> ok. The is_boolean/1 tests are necessary to ensure that the guard fails for calls such as: o(true, not_boolean) However, because of a bug in v3_core, is_boolean/1 tests were added when they were not necessary. Here is an example: f(B) when not B -> ok. That would be translated to: f(B) when (B =:= false) and is_boolean(B) -> ok. The following translation will work just as well. f(B) when B =:= false -> ok. Correct the bug to suppress those unnecessary is_boolean/1 tests. --- lib/compiler/src/v3_core.erl | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl index 0941ad5dd5..7c229210a0 100644 --- a/lib/compiler/src/v3_core.erl +++ b/lib/compiler/src/v3_core.erl @@ -469,7 +469,8 @@ unforce_tree([#iset{var=#c_var{name=V},arg=Arg0}|Es], D0) -> unforce_tree(Es, D); unforce_tree([#icall{}=Call], D) -> unforce_tree_subst(Call, D); -unforce_tree([Top], _) -> Top. +unforce_tree([#c_var{name=V}], D) -> + gb_trees:get(V, D). unforce_tree_subst(#icall{module=#c_literal{val=erlang}, name=#c_literal{val='=:='}, -- cgit v1.2.3