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2009-12-14Merge branch 'bg/compiler-bopt-bug' into ccase/r13b04_devErlang/OTP
* bg/compiler-bopt-bug: beam_bool: Fix generation of code that does not validate Fix crash in beam_bool OTP-8338 Using complex boolean expressions in ifs could cause the compiler to either crash or teminate with an internal error. (Thanks to Simon Cornish.)
2009-12-11beam_bool: Fix generation of code that does not validateBjörn Gustavsson
The following code (by Simon Cornish) bad(XDo1, XDo2, Do3) -> Do1 = (XDo1 =/= []), Do2 = (XDo2 =/= []), CH1 = if Do1 == true; Do1 == false,Do2==false,Do3 == blah -> ch1; true -> no end, CH2 = if Do1 == true; Do1 == false,Do2==false,Do3 == xx -> ch2; true -> no end, {CH1,CH2}. is optimized by beam_bool even though the optimization is not safe. The trouble is that an assignment to {y,0} no longer occurs on all paths leading to its use. The bug is in dst_regs/2 which is supposed to return a set of all registers assigned in a code block, but it ignores registers assigned in 'move' instructions. Fix the bug by taking 'move' instructions into account. This change is safe since it can only cause more registers to be added to the MustBeKilled and MustBeUnused sets in ensure_opt_safe/6, which means that it can only cause the optimization to be turned off for code that used to be optimized.
2009-12-10Fix crash in beam_boolBjörn Gustavsson
The following code crashes beam_bool: bad(XDo1, XDo2, Do3) -> Do1 = (XDo1 =/= []), Do2 = (XDo2 =/= []), if Do1 =:= true; Do1 =:= false, Do2 =:= false, Do3 =:= delete -> no end. (Reported by Simon Cornish; minimized by Kostis Sagonas.) For the moment fix the bug in the simplest and safest way possible (basically, instead of crashing just don't do the optimization). In a future major release (e.g. R14), the following improvements could be considered: * In beam_bool, it should be possible to move the Do1 and Do2 expressions to the pre-block and still optimize the expression in the 'if' statement. * In sys_core_fold, it should be possible to eliminate the try/catch around the guard expression in the 'if', because none of the guard tests can actually fail.
2009-12-09compiler: Teach 'slim' to omit compilation infoBjörn Gustavsson
The original intention for the undocumented 'slim' option was to omit non-essential parts of *.beam files to reduce the size of the primary bootstrap. Therefore, debug information and local function information (only used by xref, not by the loader) are omitted, but information about the compilation time and compiler version are still included. Including compilation information is troublesome, however, when committing the bootstrap into a revision control system, because every beam file is guaranteed to be changed every time the bootstrap is updated. Therefore, change the 'slim' option to also omit compilation information.
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP