From 9b0122b65bdcafbae2a3cfd3299903da0948acab Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 28 Nov 2017 07:28:25 +0100 Subject: Don't build a stacktrace if it's only passed to erlang:raise/3 Consider the following function: function({function,Name,Arity,CLabel,Is0}, Lc0) -> try %% Optimize the code for the function. catch Class:Error:Stack -> io:format("Function: ~w/~w\n", [Name,Arity]), erlang:raise(Class, Error, Stack) end. The stacktrace is retrieved, but it is only used in the call to erlang:raise/3. There is no need to build a stacktrace in this function. We can avoid the building if we introduce an instruction called raw_raise/3 that works exactly like the erlang:raise/3 BIF except that its third argument must be a raw stacktrace. --- lib/compiler/src/genop.tab | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'lib/compiler/src/genop.tab') diff --git a/lib/compiler/src/genop.tab b/lib/compiler/src/genop.tab index 397e478e1e..d59bb241a8 100755 --- a/lib/compiler/src/genop.tab +++ b/lib/compiler/src/genop.tab @@ -554,3 +554,13 @@ BEAM_FORMAT_NUMBER=0 ## Do a garbage collection if necessary to allocate space on the heap ## for the result. 160: build_stacktrace/0 + +## @spec raw_raise +## @doc This instruction works like the erlang:raise/3 BIF, except that the +## stacktrace in x(2) must be a raw stacktrace. +## x(0) is the class of the exception (error, exit, or throw), +## x(1) is the exception term, and x(2) is the raw stackframe. +## If x(0) is not a valid class, the instruction will not throw an +## exception, but store the atom 'badarg' in x(0) and execute the +## next instruction. +161: raw_raise/0 -- cgit v1.2.3