search for: 9d9cf5

Displaying 3 results from an estimated 3 matches for "9d9cf5".

2012 Jul 19
4
[LLVMdev] LLVM compile speed significantly slower than GCC (w/ test case)
...ng 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 slow wouldn't have much o...
2012 Jul 19
0
[LLVMdev] LLVM compile speed significantly slower than GCC (w/ test case)
...e 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...
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 -emit-llvm sha1test.c $ opt -time-pass...