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On Mon, Jun 4, 2012 at 3:52 PM, Tanya Lattner <lattner at apple.com> wrote: > LLVMers, > > Traffic on llvm-dev is quite high and while the majority of it is LLVM > development related, there are many other mails related to clients or other > projects. > > Having an llvm-users doesn't make any sense, but perhaps having a > llvm-clients or llvm-general mailing list

LLVMers, Traffic on llvm-dev is quite high and while the majority of it is LLVM development related, there are many other mails related to clients or other projects. Having an llvm-users doesn't make any sense, but perhaps having a llvm-clients or llvm-general mailing list may help offload some of the traffic. What do people think? Any other suggestions to divide up the traffic and reach

I wanted to use LLVM for my math parser but it seems that floating point optimizations are poor. For example consider such C code: float foo(float x) { return x+x+x; } and here is the code generated with "optimized" live demo: define float @foo(float %x) nounwind readnone { entry: %0 = fmul float %x, 2.000000e+00 ; <float> [#uses=1] %1 = fadd float %0, %x

And also the resulting assembly code is very poor: 00460013 movss xmm0,dword ptr [esp+8] 00460019 movaps xmm1,xmm0 0046001C addss xmm1,xmm1 00460020 pxor xmm2,xmm2 00460024 addss xmm2,xmm1 00460028 addss xmm2,xmm0 0046002C movss dword ptr [esp],xmm2 00460031 fld dword ptr [esp] Especially pxor&and instead of movss (which is

I'm aware that there are IEEE requirements for floating point. But all C/C++ compilers like GCC or MSVC have unsafe/fast math switches that disable all problems related to NaN/Inf/+-0/precision etc because in some applications those are not as important as performance (for example graphics calculation). But as I understand, LLVM currently does not have such unsafe/fast math optimizations

Thanks for replying so fast. This UnsafeFPMath trick in fact solves "pxor adds" case, but the resulting code is still not as good as I expected from LLVM. For example expressions like "1+x+1+x+1+x+1+x" (basically adding a lot of constants and variables) are complied to a long series off <add>s both in IR and assembly code. Both GCC and MSVC generates C1*x +C2 (mov +