Binutils 2.31 Offers Faster DLL Linking For Cygwin/Mingw, Freescale S12Z Support

[phoronix]

Phoronix: Binutils 2.31 Offers Faster DLL Linking For Cygwin/Mingw, Freescale S12Z Support

A new release of the Binutils collection of important tools is now available with a number of new features and improvements...

http://www.phoronix.com/scan.php?page=news_item&px=Binutils-2.31-Released

[Weasel]

The x86 assembler now supports a -O[2|s] command-line options to enable alternate shorter instruction encodings.

Where can I find more information about this? Has GAS finally reached multi-pass capability, or what exactly does it refer to? In the 2.31 manual, I can't find it in the command line options, where am I supposed to look?

Furthermore I don't understand why it has to be an option instead of the default.

Oh well, I guess the worst assembler just got a little better.

[cbxbiker61]

If binutils 2.31 is installed "info as". In the x86 options it says that -Os includes -O2 optimization.

[Weasel]

If binutils 2.31 is installed "info as". In the x86 options it says that -Os includes -O2 optimization.

Yeah but what exactly does it do? That's what I'm trying to find. What opcodes (examples?) and what kind of shortening. There's *many* such tricks in x86.

One of the problems with GAS compared to virtually every other assembler has always been lack of true multi-pass, and only did it on branch shortening encoding. Other instructions, if they forward referenced a symbol, would always be encoded with largest encoding possible (i.e. 32-bit immediate instead of sign-extended 8-bit).

I don't know if this fixes that or what.

Also why isn't it the default? Is a reason given or nah?