search for: fmath

This is of course not homework. I am trying to understand how fast math optimizations work in llvm. When I compared IR for both the programs, the only thing I have noticed is that fdiv and fmul are replaced with fdiv fast and fmul fast. Not sure what happens in fdiv fast and fmul fast. I feel that its because d/max is really small number and fast-math does not care about small numbers and consider

...VM-9/llvm-project/build/Debug/bin/clang" "-cc1" "-triple" "msp430" "-emit-llvm" "-disable-free" "-main-file-name" "main.c" "-mrelocation-model" "static" "-mthread-model" "posix" "-fmath-errno" "-masm-verbose" "-mconstructor-aliases" "-nostdsysteminc" "-dwarf-column-info" "-debugger-tuning=gdb" "-target-linker-version" "305" "-momit-leaf-frame-pointer" "-coverage-notes-file" "/Users/...

...lls are no longer elided, though using the "as-if" rule, the tests are still eliminated and 'useMathName' becomes: (void)exp(1.0); (void)exp(1.0); return 0; So I changed our implementation so that '-fno-math-errno' is the default for the tool-chain, and the '-fmath-errno' option is not passed on to the CC1 phase. I expected that this would allow the compiler to elide the calls, but it is not doing so. I don't want to use '-ffast-math' as this has lots of FP issues, and I don't want to make it the default. Any idea why the math functi...

...VM-9/llvm-project/build/Debug/bin/clang" "-cc1" "-triple" "msp430" "-emit-llvm" "-disable-free" "-main-file-name" "main.c" "-mrelocation-model" "static" "-mthread-model" "posix" "-fmath-errno" "-masm-verbose" "-mconstructor-aliases" "-nostdsysteminc" "-dwarf-column-info" "-debugger-tuning=gdb" "-target-linker-version" "305" "-momit-leaf-frame-pointer" "-coverage-notes-file" "/Users/...

...but I thought that the ‘-fno-math-errno’ option was to tell the optimiser to assume that ‘errno’ is not modified by the math functions. Explicitly providing ‘-fno-math-errno’ is not restoring the elision optimisation that was performed by LLVM v3.8, and this is really only a driver option, with ‘-fmath-errno’ passed onto CC1 if ‘MathErrno’ is true, and omitted if false. I certainly agree that if ‘MathErrno’ is true, then the compiler should not elide the call as it has to assume that there are memory write side-effects. It already models the math functions as built-ins and determine the expe...

...VM-9/llvm-project/build/Debug/bin/clang" "-cc1" "-triple" "msp430" "-emit-llvm" "-disable-free" "-main-file-name" "main.c" "-mrelocation-model" "static" "-mthread-model" "posix" "-fmath-errno" "-masm-verbose" "-mconstructor-aliases" "-nostdsysteminc" "-dwarf-column-info" "-debugger-tuning=gdb" "-target-linker-version" "305" "-momit-leaf-frame-pointer" "-coverage-notes-file" "/Users/...

...VM-9/llvm-project/build/Debug/bin/clang" "-cc1" "-triple" "msp430" "-emit-llvm" "-disable-free" "-main-file-name" "main.c" "-mrelocation-model" "static" "-mthread-model" "posix" "-fmath-errno" "-masm-verbose" "-mconstructor-aliases" "-nostdsysteminc" "-dwarf-column-info" "-debugger-tuning=gdb" "-target-linker-version" "305" "-momit-leaf-frame-pointer" "-coverage-notes-file" "/Users/...

Dear friends. This is again a very simple question, and I hope you will accept it. I have a dataset with variables in columns all with their names. Now I want to add a column indicating simply identity of patients, numbered according to row. There are 34 rows. So I did: >ID <- c(1:34) but was not allowed to >Ptt <- cbind(patients,ID) and was informed that >Error: names attribute

...osix InstalledDir: /path/to/llvm/bin "/path/to/musl/lib/ld-musl-x86_64.so.1" -cc1 -triple x86_64-pc-linux-musl -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name hello.c -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -v -dwarf-column-info -debugger-tuning=gdb -coverage-notes-file /path/to/hello/hello.gcno -resource-dir /path/to/musl/lib/clang/4.0.0 -isysroot /path/to/musl -internal-isystem /path/to/musl/usr/local/include -internal-isys...

...e-free" "-disable-llvm-verifier" "-discard-value-names" "-ma in-file-name" "crash.c" "-mrelocation-model" "pic" "-pic-level" "2" "-mthread-mo del" "posix" "-mframe-pointer=none" "-fmath-errno" "-fno-rounding-math" "-masm-v erbose" "-mconstructor-aliases" "-munwind-tables" "-target-cpu" "x86-64" "-dwarf -column-info" "-resource-dir" "C:\\Program Files\\LLVM\\lib\\clang\\10.0.0" "-in...

On Tue, Jun 3, 2014 at 7:59 AM, Nancy <nancydreaming at gmail.com> wrote: >> First, you could switch to ld.gold instead of ld.bfd. It uses much > $ln -s `which gold` /usr/local/bin/ld > >> the idea. I think for autoconf you need ".../configure >> --enable-split-dwarf" to use this. >> > $.../configure --enable-targets=x86 --enable-split-dwarf >

...ifier" >> "-discard-value-names" "-ma >> in-file-name" "crash.c" "-mrelocation-model" "pic" "-pic-level" "2" >> "-mthread-mo >> del" "posix" "-mframe-pointer=none" "-fmath-errno" "-fno-rounding-math" >> "-masm-v >> erbose" "-mconstructor-aliases" "-munwind-tables" "-target-cpu" "x86-64" >> "-dwarf >> -column-info" "-resource-dir" "C:\\Program >> Fil...

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. Both work well for their stated purpose, > llvm.sqrt should not be slower than sqrt even on linux. Both > llvm.sqrt and sqrt could be much

...the work. >> >> -Chris > > What exactly is the work for llvm.sqrt on Linux? Ah sorry, llvm.sqrt works fine on linux. The issue is that a raw call to sqrt() in a C program doesn't typically compile to llvm.sqrt on linux, because it sets errno. This can be controlled with -fmath-errno. -Chris

...ta.cpp:87! 0 clang 0x09e9d5d9 llvm::sys::PrintStackTrace(_IO_FILE*) + 41 Stack dump: 0. Program arguments: /home/ali/llvm-3.3.src/Release+Asserts/bin/clang -cc1 -triple i386-pc-linux-gnu -emit-obj -mrelax-all -disable-free -main-file-name somefile.bc -mrelocation-model static -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -target-cpu pentium4 -target-linker-version 2.21.53.20110810 -resource-dir /home/ali/llvm-3.3.src/Release+Asserts/bin/../lib/clang/3.3 -fdebug-compilation-dir /home/ali/Code/ReyMRE/vm/tools/ReyVM -ferror-limit 19 -fmessage-length 113 -mstackrealign -fobjc-r...

...-discard-value-names" "-ma >> >> in-file-name" "crash.c" "-mrelocation-model" "pic" "-pic-level" "2" >> >> "-mthread-mo >> >> del" "posix" "-mframe-pointer=none" "-fmath-errno" "-fno-rounding-math" >> >> "-masm-v >> >> erbose" "-mconstructor-aliases" "-munwind-tables" "-target-cpu" >> "x86-64" >> >> "-dwarf >> >> -column-info" "-reso...

...uses EDOM for pow(-Inf, 0.5) even on platforms where the system library implementation of pow does not cause this situation to arise. A sample program that (on some platforms, such as Linux on x86-64) completes successfully with optimizations off, and aborts with LLVM's optimization follows; -fmath-errno does not help, and it is not expected to, because it is designed to retain setting errno to non-zero (not to prevent spuriously setting errno). #include <errno.h> volatile double inf = -__builtin_inf(); double pow(double, double); void abort(void); int main(void) { errno = 0; pow(...

...4.0 Selected GCC installation: /usr/lib/gcc/avr/5.4.0 (in-process) "/usr/local/bin/clang-11" -cc1 -triple avr -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name main.cpp -mrelocation-model static -mthread-model posix -mframe-pointer=all -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -target-cpu atmega328p -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -v -resource-dir /usr/local/lib/clang/11.0.0 -fdeprecated-macro -fdebug-compilation-dir /home/alex/tmp/clang-avr -ferror-limit 19 -fmessage-length 0...

Hi, I am trying to compare the loop vectorizers effectiveness for different targets relative to each other. That way, I am hoping to find loops that are not vectorized - but could be - on my target by finding other targets doing this successfully. With some luck, there might be something in the Target files that could be fixed with improved vectorization as a result... I would like to do

.../lib/gcc/x86_64-linux-gnu/7.3.0 Candidate multilib: .;@m64 Selected multilib: .;@m64 "/home/mahesha/LLVM/install/bin/clang-9" -cc1 -triple x86_64-unknown-linux-gnu -E -save-temps=cwd -disable-free -main-file-name hello.cpp -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath- errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -v -resource-dir /home/mahesha/LLVM/install/lib/clang/9.0.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0 -internal-isystem /...