otp.git - Mirror of Erlang/OTP repository.

Age	Commit message (Collapse)	Author
2017-09-14	Merge branch 'bjorn/erts/relative-jumps'	Björn Gustavsson
	* bjorn/erts/relative-jumps: Pack failure labels in i_select_val2 and i_select_tuple_arity2 Optimize i_select_tuple_arity2 and is_select_lins Rewrite select_val_bins so that its labels can be packed Pack sequences of trailing 'f' operands Implement packing of 'f' and 'j' Make sure that mask literals are 64 bits Use relative failure labels Add information about offset to common group start position Remove JUMP_OFFSET Refactor instructions to support relative jumps Introduce a new trace_jump/1 instruction for tracing Avoid using $Src more than once
2017-09-14	Use relative failure labels	Björn Gustavsson
	Relative failure in itself is not an optimization, but we plan to pack failure labels in the future to save memory.
2017-09-14	Remove JUMP_OFFSET	Björn Gustavsson
	It has served its purpose.
2017-09-13	Refactor instructions to support relative jumps	Björn Gustavsson
	Introduce new macros that can be used for relative jumps and use them consistently. Test that everything works by using a non-zero constant JUMP_OFFSET. The loader subtracts JUMP_OFFSET from loaded labels, and all instructions that use 'f' operands add it back.
2017-09-11	Use the correct name of the parameter	Björn Gustavsson

2017-08-31	Add annotations for likely/unlikely	Björn Gustavsson
	In a correct Erlang programs, we can expect that: * A GC test instruction (such as test_heap) is more likely not to do the GC. * A BIF is more likely to succeed than to fail. * A BIF is more likely to fail in a guard than in a body. * An apply or fun call is likely to succeed. Annotate conditions accordingly.
2017-08-15	Slightly optimize updating of maps	Björn Gustavsson
	The instruction put_map_assoc/5 (used for updating a map) has a failure operand, but it can't actually fail provided that its "map" argument is a map. The following code: M#{key=>value}. will be compiled to: {test,is_map,{f,3},[{x,0}]}. {line,[...]}. {put_map_assoc,{f,0},{x,0},{x,0},1,{list,[{atom,key},{atom,value}]}}. return. {label,3}. %% Code that produces a 'badmap' exception follows. Because of the is_map instruction, {x,0} always contains a map when the put_map_assoc instruction is executed. Therefore we can remove the failure operand. That will save one word, and also eliminate two tests at run-time. The only problem is that the compiler in OTP 17 did not emit a is_map instruction before the put_map_assoc instruction. Therefore, we must add an instruction that tests for a map if the code was compiled with the OTP 17 compiler. Unfortunately, there is no safe and relatively easy way to known that the OTP 17 compiler was used, so we will check whether a compiler before OTP 20 was used. OTP 20 introduced a new chunk type for atoms, which is trivial to check.
2017-08-11	Break out most instructions from beam_emu.c	Björn Gustavsson