llvm useability?

Has llvm reached the point that it is useable as a mainstream c++ compiler?
Are there benchmarks available comparing generated code to gcc4? My
primary interest is scientific-type computing.

Has llvm reached the point that it is useable as a mainstream c++ compiler?

Yes. LLVM 2.2 will be out in a few weeks, it will be the best release yet. Many people use llvm to build large C++ code bases.

Are there benchmarks available comparing generated code to gcc4? My
primary interest is scientific-type computing.

There are lots of benchmarks (see the nightly tester for example), but it always makes sense to pick your own benchmark and do an evaluation yourself. If you know of any important and self-contained benchmarks that can be added to our performance testsuite, please let us know.

The most important thing to know for numeric performance is that LLVM currently generates very poor code when targeting machines that do not have SSE2 or later. When building llvm-gcc, make sure to configure it for a CPU that has SSE2 or later to get good performance.

-Chris