I’ve been getting the impression for a while that the GCC C Compiler has been getting slower over time at compiling. To check whether this was in fact true, I timed building a popular software package (emacs) with each major version of the compiler that I could get ahold of. I also added in a few other compilers, for reference.
For the benchmark, I built the temacs part of the GNU emacs distribution (version 22.3). System used is a 1.6GHZ AMD Sempron, 512MB RAM, running Fedora 13.
The compilers used were:
- gcc – The GNU C Compiler – the standard system compiler on virtually all Linux distributions.
- llvm – Low-Level Virtual Machine – a new(ish) compiler being developed by Apple and the University of Illinois. It uses the new clang front-end.
- icc – The Intel C++ Compiler – Intel’s own compiler, known for aggressive optimizations.
- pcc – The Portable C Compiler – a modernized version of the original BSD Unix system compiler.
Optimization off
|
Compiler (version) |
Compile Time (-O0) seconds |
% change (vs. gcc 3.4) |
% change (vs. prev version) |
| gcc 2.7.2.3 | 13.9 | +35% | |
| gcc 2.8.1 | 14.5 | +32% | -4% |
| gcc 2.95.3 | 16.4 | +23% | -13% |
| gcc 3.0.4 | 20.1 | +6% | -23% |
| gcc 3.1.1 | 22.0 | -3% | -9% |
| gcc 3.2.3 | 21.9 | -3% | +1% |
| gcc 3.3.6 | 20.7 | +3% | +5% |
| gcc 3.4.6 | 21.3 | -3% | |
| gcc 4.0.4 | 22.4 | -5% | -5% |
| gcc 4.1.2 | 22.5 | -5% | -1% |
| gcc 4.2.4 | 22.2 | -4% | +1% |
| gcc 4.3.5 | 25.3 | -19% | -14% |
| gcc 4.4.5 | 26.7 | -25% | -6% |
| gcc 4.5.2 | 28.8 | -35% | -7% |
| gcc 4.6 (pre) | 29.4 | -38% | -2% |
| llvm 2.8 | 29.6 | -39% | |
| llvm 2.9 (pre) | 19.9 | +7% | +33% |
| icc 11.1 | 21.0 | +1% | |
| icc 12.0 | 17.5 | +18% | +17% |
| pcc 1.1 (pre) | 21.6 | -1% |
Optimization On
|
Compiler (version) |
Compile Time (-O2 -g) seconds |
% change (vs. gcc 3.4) |
% change (vs. prev version) |
| gcc 2.7.2.3 | 24.0 | +64% | |
| gcc 2.8.1 | 27.7 | +59% | -15% |
| gcc 2.95.3 | 40.0 | +41% | -44% |
| gcc 3.0.4 | 52.6 | +22% | -32% |
| gcc 3.1.1 | 63.7 | +6% | -21.1% |
| gcc 3.2.3 | 63.9 | +6% | +0% |
| gcc 3.3.6 | 66.5 | +2% | -4% |
| gcc 3.4.6 | 67.6 | -2% | |
| gcc 4.0.4 | 76.1 | -13% | -13% |
| gcc 4.1.2 | 83.9 | -24% | -10% |
| gcc 4.2.4 | 103.4 | -53% | -23% |
| gcc 4.3.5 | 100.7 | -49% | +3% |
| gcc 4.4.5 | 109.1 | -61% | -8% |
| gcc 4.5.2 | 112.6 | -67% | -3% |
| gcc 4.6 (pre) | 113.7 | -68% | -1% |
| llvm 2.8 | 79.1 | -17% | |
| llvm 2.9 (pre) | 72.9 | -8% | +8% |
| icc 11.1 | 91.6 | -36% | |
| icc 12.0 | 96.6 | -43% | -5% |
| pcc 1.1 (pre) | 28.8 | +57% |