search for: funsafe

...h the same as vector FP math? TTI seems like > > a good place to expose that information. If the semantics are indeed > > different, then the vectorizer would require fast-math flags in order to > > vectorize FP operations (similarly, gcc's man page says it requires > > -funsafe-math-optimizations for vectorization unless -mfpu=neon or similar > > is specified). In this context, this different-semantics query would return > > true if: > > The semantics is indeed different, VFP is IEEE-754 compliant while > NEON is not. We don't want to stop the co...

...e is: Are the semantics of scalar FP math the same as vector FP math? TTI seems like a good place to expose that information. If the semantics are indeed different, then the vectorizer would require fast-math flags in order to vectorize FP operations (similarly, gcc's man page says it requires -funsafe-math-optimizations for vectorization unless -mfpu=neon or similar is specified). In this context, this different-semantics query would return true if: The semantics is indeed different, VFP is IEEE-754 compliant while NEON is not. We don't want to stop the compiler from using VFP for FP math,...

...e is: Are the semantics of scalar FP math the same as vector FP math? TTI seems like a good place to expose that information. If the semantics are indeed different, then the vectorizer would require fast-math flags in order to vectorize FP operations (similarly, gcc's man page says it requires -funsafe-math-optimizations for vectorization unless -mfpu=neon or similar is specified). In this context, this different-semantics query would return true if: !(isDarwin OR ARMISA >= v8 OR fpMath == NEON) and then we need to teach people to use -mfpu=neon ;) I think this more-or-less matches what y...

...code to constant fold a calls to libmath functions -- but the libmath functions have certain semantics regarding how errno is set which I don't really want to deal with. Other compilers have options to enable the direct use of fp instructions for math operations (gcc has -fno-math-errno, -funsafe-math-optimizations and -fno-trapping-math), this could be useful also for LLVM. Assuming there is such an option, should I modify the visitCallInst function to generate machine instructions directly for calls to math functions or is it better to include a pass which converts the calls into intr...

On 22 March 2016 at 11:34, James Molloy <James.Molloy at arm.com> wrote: > I don’t think this part is right. The denormal flag would have to be set by > whatever code generates the FP instruction, which would be Clang’s codegen > layer. So the if (Darwin) would be there, not in TTI. Right, I meant the information to set/not set would be in TTI, not the actual setting. I don't

...t), we should support GCC's FP options: > https://gcc.gnu.org/onlinedocs/gcc-6.2.0/gcc/Optimize-Options.html#Optimize-Options <https://gcc.gnu.org/onlinedocs/gcc-6.2.0/gcc/Optimize-Options.html#Optimize-Options> > > -ffp-contract=style > -ffast-math > -fno-math-errno > -funsafe-math-optimizations > -fassociative-math > -freciprocal-math > -ffinite-math-only > -fno-signed-zeros > -fno-trapping-math > -frounding-math > -fsignaling-nans > -fsingle-precision-constant > > etc, and the relevant negations of these options. We can't predict how...

On Jan 7, 2010, at 4:04 PMPST, Chris Lattner wrote: > On Jan 7, 2010, at 3:53 PM, Robert A. Zeh wrote: > On Jan 7, 2010, at 11:48 AM, Chris Lattner <clattner at apple.com> wrote: >> >>> There is a fundamental difference between sqrt() and llvm.sqrt: the >>> former is defined on negative values and sets errno (on linux). The >>> later is undefined.

Hi Viswanath, Great to see it coming. > Phil, > > As you mentioned earlier, could you please address all > compile and linker errors/warnings coming out of Ne10 library? [Phil Wang] OK, I will deliver it. But I will try to add -funsafe-math-optimisations flag to our build system first. Also I will have a look into our build system on Linux. From your previous response, I guess there is something wrong. > You can find my working Ne10 repo at [1] [Phil Wang] Great help. > Compile warnings related to Ne10: > i. ..NE10_ini...

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

...e, it means (barring anything that we explicitly > document and choose not to support), we should support GCC's FP options: > https://gcc.gnu.org/onlinedocs/gcc-6.2.0/gcc/Optimize-Options.html# > Optimize-Options > > -ffp-contract=style > -ffast-math > -fno-math-errno > -funsafe-math-optimizations > -fassociative-math > -freciprocal-math > -ffinite-math-only > -fno-signed-zeros > -fno-trapping-math > -frounding-math > -fsignaling-nans > -fsingle-precision-constant > > etc, and the relevant negations of these options. We can't predict how &...

...it as required. For functions like sin/cos/etc, which do not set errno, you should be able to recognize an external function with that name and generate code for it. > Other compilers have options to enable the direct use of fp instructions for > math operations (gcc has -fno-math-errno, -funsafe-math-optimizations and > -fno-trapping-math), this could be useful also for LLVM. Yes, but this is really a separate issue, at least initially. > Assuming there is such an option, should I modify the visitCallInst > function to generate machine instructions directly for calls to math...

...havior" to "ignore".) -f[no-]finite-math-only Controls no_honor_nans and no_honor_infinities. -f[no-]unsafe-math-optimizations Turns no_signed_zeros, allow_reciprocal, allow_approximate_fns, and allow_reassociation on or off. Also, sets except_behavior to "on" for -funsafe-math-optimizations. (Currently, -fno-]unsafe-math-optimizations clears except_behavior, but I regard this as a bug.) All command line options will override any previous values of all settings they control with options taking effect in a left-to-right manner. ====================== pragmas =====...

Hi Bob, > 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 + mul + add). > > I am new to using LLVM. I am using Visual Studio 2008 on Windows, targeting > 32-bit X86 code. I'm using

On 17.11.2016 09:51, Ristow, Warren wrote: > Those are all good points. Your reassociation point in the context of > inlining is particularly interesting. > > > > FWIW, we also have a case where a customer wants '-fno-associative-math' > to suppress reassociation under '-ffastmath'. It would take me a while > to find the specifics of the issue, but it was

Hi Jack, On 29/05/13 22:04, Jack Howarth wrote: > On Wed, May 29, 2013 at 03:25:30PM +0200, Duncan Sands wrote: >> Hi Jack, I pulled the loop vectorizer and fast math changes into the 3.3 branch, >> so hopefully they will be part of 3.3 rc3 (and 3.3 final!). It would be great >> if you could redo the benchmarks rc3. >> > > Duncan, > As requested, appended

...;d like to solicit information about whether other targets have/need different denormal options than are described above. Futher, I'd suggest that for any architecture that supports FTZ behavior, a well-document default be automatically set when fast math is enabled via -Ofast, -ffast-math, or -funsafe-math-optimizations unless that option is turned off by a subsequent -fno-fast-math/-fno-unsafe-math-optimizations option or overridden by a subsequent -fdenormal-fp-math option, and if -fdenormal-fp-math is used, some code will be emitted to set the relevant hardware controls. I don't have a s...

...k/include -fopt-info -pipe -Wall -Wextra -Ofast -DCLS=64 -fPIC -floop-nest-optimize --param simultaneous-prefetches=16 -fprefetch-loop-arrays -msse4.2 -mrecip=all -funroll-loops -fdelete-null-pointer-checks --param prefetch-latency=32 -ffast-math -ftree-vectorize -funsafe-math-optimizations -Wno-error=unused-parameter -Wno-error=type-limits -fPIC -fvisibility-inlines-hidden -Werror=date-time -std=c++1y -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -Wno-maybe-uninitialized -Wdelete-non-virtual-dtor -Wno-comment -...

...flap|fmudflapth:-fno-builtin -fno-merge-constants} %{coverage:-fprofile-arcs -ftest-coverage} *cc1plus: *link_gcc_c_sequence: %{static:--start-group} %G %L %{static:--end-group}%{!static:%G} *link_ssp: %{fstack-protector|fstack-protector-all:-lssp_nonshared -lssp} *endfile: %{ffast-math|funsafe-math-optimizations:crtfastmath.o%s} %{shared|pie:crtendS.o%s;:crtend.o%s} crtn.o%s *link: %{!static:--eh-frame-hdr} -m %(link_emulation) %{shared:-shared} %{!shared: %{!ibcs: %{!static: %{rdynamic:-export-dynamic} %{!dynamic-linker:-dynamic-linker %(dynamic_linker)}} %{s...

On Sat, Apr 27, 2013 at 7:26 PM, Nick Lewycky <nicholas at mxc.ca> wrote: > On 04/26/2013 04:20 PM, Owen Anderson wrote: > >> >> On Apr 26, 2013, at 3:07 PM, Sergei Larin <slarin at codeaurora.org >> <mailto:slarin at codeaurora.org>**> wrote: >> >> Dan, >>> Thank you for the quick and throughout reply. First paragraph pretty

Hi Sanjay, You are right. I tried XL and gcc 4.8.2 for PPC and I also got multiply-and-add operations. I supported my statement on what I read in the gcc man page. -ffast-math is used in clang to set fp-contract to fast (default is standard) and in gcc it activates (among others) the flag -funsafe-math-optimizations whose description includes: "Allow optimizations for floating-point arithmetic that (a) assume that arguments and results are valid and (b) may violate IEEE or ANSI standards." I am not a floating point expert, for the applications I care usually more precision is bet...