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| author | Björn Gustavsson <[email protected]> | 2016-02-19 07:51:35 +0100 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2016-02-23 09:16:12 +0100 |
| commit | 8aa4ff517c3dcc119ca593616875195895301189 (patch) | |
| tree | bac0046501d0c4e6696ad4243b4f7697861f75d2 /lib/compiler/src | |
| parent | 48411ad12f4d730412895e90c188c2d8f7813ce5 (diff) | |
| download | otp-8aa4ff517c3dcc119ca593616875195895301189.tar.gz otp-8aa4ff517c3dcc119ca593616875195895301189.tar.bz2 otp-8aa4ff517c3dcc119ca593616875195895301189.zip | |
sys_core_fold: Optimize clause/4
Save work the *extremely* common case that the guard is
a literal.
Diffstat (limited to 'lib/compiler/src')
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 43ce9a7172..b78507c47e 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1081,12 +1081,16 @@ is_atom_or_var(_) -> false. clause(#c_clause{pats=Ps0,guard=G0,body=B0}=Cl, Cexpr, Ctxt, Sub0) -> {Ps1,Sub1} = pattern_list(Ps0, Sub0), Sub2 = update_types(Cexpr, Ps1, Sub1), - GSub = case {Cexpr,Ps1} of - {#c_var{name='_'},_} -> + GSub = case {Cexpr,Ps1,G0} of + {_,_,#c_literal{}} -> + %% No need for substitution tricks when the guard + %% does not contain any variables. + Sub2; + {#c_var{name='_'},_,_} -> %% In a 'receive', Cexpr is the variable '_', which represents the %% message being matched. We must NOT do any extra substiutions. Sub2; - {#c_var{},[#c_var{}=Var]} -> + {#c_var{},[#c_var{}=Var],_} -> %% The idea here is to optimize expressions such as %% %% case A of A -> ... |