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---------- Forwarded message ---------- From: Rugxulo rugxulo@gmail.com Date: Tue, 20 Apr 2010 19:13:05 -0500 Subject: Re: [Fwd: GCC 4.5.0 Released] To: Adriaan van Os gpc@microbizz.nl

Hi, just a few warnings from me. ;-)

On 4/19/10, Adriaan van Os gpc@microbizz.nl wrote:

The Free Software Foundation and the GNU Compiler Collection (GCC) development team have released GCC 4.5.0.

Clang is also self-hosting now, and ClangBSD can bootstrap (currently in testing but seems to basically work, from what I hear).

The developers have measured performance improvements of 5% to 10% on high-performance computing benchmarks. (Of course, results vary depending on choice of CPU, benchmark, and optimization options.)

In my (horribly lame) experience, I saw some bad regressions with 4.4.2 vs. earlier GCCs. Granted, it was just one really weird case, but still, it makes me think even moreso that GCC is only 686-tuned these days. (I was trying to benchmark something on my old old 586.) It worries me a bit since I just assumed 4.x was always way better. (Note that I never bothered to isolate the problem just yet, it wasn't crucial or anything, just really odd. And it was a C program, not Pascal.)

GCC 4.5.0 is now capable of "link-time optimization".

Only using an ELF container (although non-ELF targets can somehow possibly use it too, allegedly). Hopefully not as exclusive as Gold linker (x86/x86-64 ELF only). I do really feel like all the world's a Linux these days. :-/

GCC also generates better debug information for optimized code, including information about the value of variables that have been optimized away.

In other words, you need GDB 7+ by default (else have to choose an older Dwarf debug format via --dwarf-2 or whatever).