Re: Can GCC use more than 4G while compiling ?

[Tomas Kalibera <kalibera@cs.purdue.edu>]

Ian Lance Taylor wrote:
> Tomas Kalibera <kalibera@cs.purdue.edu> writes:
>
>   
>> GCC runs out of memory while compiling my very large generated source
>> file. Although I have x86_64 with more than 4G of RAM, it seems that
>> GCC only uses something less than 4G. Is there a way to allow GCC to
>> use more ? Something like ggc-heap-size...
>>
>> I'm using GCC 4.2.3, compiled from sources, gcc binary is a 64-bit
>> executable.
>>     
>
> What is the exact error message?  Are all the compiler binaries 64-bit
> executables?
>   
- "virtual memory exhausted: Cannot allocate memory"
- yes, I re-checked all binaries are 64-bit

I'm now trying my luck with

"--param ggc-min-expand=0 --param ggc-min-heapsize=4096"

Compilation is now by orders of magnitude slower, it's been already 
compiling the single file for 6 hours, I don't know how far it got.

The machine has 6G of RAM + 16G of swap and I can malloc more than 4G in 
a test application.
> gcc should not run out of memory until malloc or mmap fail to allocate
> any more memory.  There is no maximum heap size.  gcc's garbage
> collector doesn't run at arbitrary times; in particular it doesn't run
> when there is an allocation failure, nor when the heap reaches a
> certain size.
>   
OK, and there is not any special option needed when compiling the gcc 
compiler ?
I compiled with

Target: x86_64-pc-linux-gnu
Configured with: ./configure 
 --prefix=my_directory
 --host=x86_64-pc-linux-gnu 
 --build=x86_64-pc-linux-gnu 
 --disable-altivec 
 --enable-nls 
 --with-system-zlib 
 --enable-multilib 
 --enable-languages=c,c++ 
 --enable-shared 
 --enable-threads=posix 
 --enable-__cxa_atexit 
 --enable-clocale=gnu 
 --enable-mpfr
Thread model: posix
gcc version 4.2.3


Thanks, Tomas
> Ian
>