Displaying 3 results from an estimated 3 matches for "7f5714f4".
2012 Jul 19
4
[LLVMdev] LLVM compile speed significantly slower than GCC (w/ test case)
...le to follow, as well as being a relatively
data-intensive piece of code.
I compiled the file with both compilers for the arm-none-eabi triple.
The numbers I get are as follows:
GCC (4.5.2, Windows build from CodeSourcery) - With -O0: 110ms, with -O2: 215ms
Clang/LLVM (Release mode, LLVM git hash 7f5714f4..., clang git hash
9d9cf5...) - With -O0: 110ms, with -O2: 640ms
The compilers are essentially identical for the -O0 case, but when
compiling with -O2, LLVM takes almost three times as long as GCC.
I'm not sure whether this file is unusual in some way, such that
fixing whatever makes this slo...
2012 Jul 19
0
[LLVMdev] LLVM compile speed significantly slower than GCC (w/ test case)
...latively
> data-intensive piece of code.
>
> I compiled the file with both compilers for the arm-none-eabi triple.
> The numbers I get are as follows:
>
> GCC (4.5.2, Windows build from CodeSourcery) - With -O0: 110ms, with -O2: 215ms
> Clang/LLVM (Release mode, LLVM git hash 7f5714f4..., clang git hash
> 9d9cf5...) - With -O0: 110ms, with -O2: 640ms
>
> The compilers are essentially identical for the -O0 case, but when
> compiling with -O2, LLVM takes almost three times as long as GCC.
>
> I'm not sure whether this file is unusual in some way, such that...
2012 Jul 20
1
[LLVMdev] LLVM compile speed significantly slower than GCC (w/ test case)
>> GCC (4.5.2, Windows build from CodeSourcery) - With -O0: 110ms, with -O2: 215ms
>> Clang/LLVM (Release mode, LLVM git hash 7f5714f4..., clang git hash
>> 9d9cf5...) - With -O0: 110ms, with -O2: 640ms
Hi Matt,
I only see 2x slowdown on my machine (consistently, O2 and O3), but
that's still bad.
If you compile to IR then pass "opt -time-passes" you can get a good
idea who the culprit is:
$ clang -O0 -S -em...