From 3c0f98c1b0e74eb58a4e4e82a3ec89dc7ecdb579 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 7 Apr 2016 10:06:44 +0200 Subject: Simplify the raise instruction to reduce code size The raise/2 instruction is almost always used like this: raise x(2) x(1) Therefore, we can translate it to an internal i_raise/0 instruction that uses x(2) x(1) as its implicit operands. We will also remove the backward compatibility with R10-0. It is unlikely that anyone still is using BEAM files compiled with the R10-0 compiler, especially since most of those modules cannot be loaded. The loader will refuse to load any module that uses the old non-GCIng arithmetic instructions or the non-GCing versions of length/1 or size/1. Doing these changes will reduce both the size of the loaded BEAM code and size of the code in process_main(). --- erts/emulator/beam/ops.tab | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'erts/emulator/beam/ops.tab') diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab index 15f27835a8..96a3a72bb5 100644 --- a/erts/emulator/beam/ops.tab +++ b/erts/emulator/beam/ops.tab @@ -251,7 +251,14 @@ case_end x badmatch x if_end -raise s s + +# Operands for raise/2 are almost always in x(2) and x(1). +# Optimize for that case. +raise x==2 x==1 => i_raise +raise Trace=y Value=y => move Trace x=2 | move Value x=1 | i_raise +raise Trace Value => move Trace x=3 | move Value x=1 | move x=3 x=2 | i_raise + +i_raise # Internal now, but could be useful to make known to the compiler. badarg j -- cgit v1.2.3