[Bug c/106165] New: incorrect result when using inlined asm implementation of floor() on i686

2022-07-01 Thread xeioexception at gmail dot com via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106165

Bug ID: 106165
   Summary: incorrect result when using inlined asm implementation
of floor() on i686
   Product: gcc
   Version: 11.1.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c
  Assignee: unassigned at gcc dot gnu.org
  Reporter: xeioexception at gmail dot com
  Target Milestone: ---

$ gcc-11 -v -save-temps -O2 minified_to_string_radix.i -o 507 -lm
Using built-in specs.   
COLLECT_GCC=gcc-11  
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/11/lto-wrapper  
Target: i686-linux-gnu  
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
11.1.0-1ubuntu1~18.04.1' --with-bugurl=file:///usr/share/doc/gcc-11/READM
E.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2
--prefix=/usr --with-gcc-major-version-only --program-suffix=-11 -
-program-prefix=i686-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threa
ds=posix --libdir=/usr/lib --enable-nls --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdc
xx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin
--enable-default-pie --with-system-zlib --enable-libphobos
-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto
--enable-targets=all --enable-multiarch --disable-werror --disabl
e-cet --with-arch-32=i686 --with-multilib-list=m32,m64,mx32 --enable-multilib
--with-tune=generic --enable-checking=release --build=i686
-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix 
Supported LTO compression algorithms: zlib zstd 
gcc version 11.1.0 (Ubuntu 11.1.0-1ubuntu1~18.04.1) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-O2' '-o' '507' '-mtune=generic'
'-march=i686' '-dumpdir' '507-'
 /usr/lib/gcc/i686-linux-gnu/11/cc1 -E -quiet -v -imultiarch i386-linux-gnu
507_mini.c -mtune=generic -march=i686 -O2 -fpch-preprocess -
fasynchronous-unwind-tables -fstack-protector-strong -Wformat -Wformat-security
-o 507-507_mini.i   
ignoring nonexistent directory "/usr/local/include/i386-linux-gnu"  
ignoring nonexistent directory "/usr/lib/gcc/i686-linux-gnu/11/include-fixed"   
ignoring nonexistent directory
"/usr/lib/gcc/i686-linux-gnu/11/../../../../i686-linux-gnu/include" 
#include "..." search starts here: 
#include <...> search starts here: 
 /usr/lib/gcc/i686-linux-gnu/11/include
 /usr/local/include
 /usr/include/i386-linux-gnu
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-O2' '-o' '507' '-mtune=generic'
'-march=i686' '-dumpdir' '507-'
 /usr/lib/gcc/i686-linux-gnu/11/cc1 -fpreprocessed 507-507_mini.i -quiet
-dumpdir 507- -dumpbase 507_mini.c -dumpbase-ext .c -mtune=generic -march=i686
-O2 -version -fasynchronous-unwind-tables -fstack-protector-strong -Wformat
-Wformat-security -o 507-507_mini.s
GNU C17 (Ubuntu 11.1.0-1ubuntu1~18.04.1) version 11.1.0 (i686-linux-gnu)
compiled by GNU C version 11.1.0, GMP version 6.1.2, MPFR version
4.0.1, MPC version 1.1.0, isl version isl-0.19-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C17 (Ubuntu 11.1.0-1ubuntu1~18.04.1) version 11.1.0 (i686-linux-gnu)
compiled by GNU C version 11.1.0, GMP version 6.1.2, MPFR version
4.0.1, MPC version 1.1.0, isl version isl-0.19-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 81b68deb607ea376c8bc5126cafbdd31
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-O2' '-o' '507' '-mtune=generic'
'-march=i686' '-dumpdir' '507-'
 as -v --32 -o 507-507_mini.o 507-507_mini.s
GNU assembler version 2.30 (i686-linux-gnu) using BFD version (GNU Binutils for
Ubuntu) 2.30
COMPILER_PATH=/usr/lib/gcc/i686-linux-gnu/11/:/usr/lib/gcc/i686-linux-gnu/11/:/usr/lib/gcc/i686-linux-gnu/:/usr/lib/gcc/i686-linux-gnu/11/:/usr/lib/gcc/i686-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/i686-linux-gnu/11/:/usr/lib/gcc/i686-linux-gnu/11/../../../i386-linux-gnu/:/usr/lib/gcc/i686-linux-gnu/11/../../../../lib/:/lib/i386-linux-gnu/:/lib/../lib/:/usr/lib/i386-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/i686-linux-gnu/11/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-O2' '-o' '507' '-mtune=generic'
'-march=i686' '-dumpdir' '507.'
 /usr/lib/gcc/i686-linux-gnu/11/collect2 -plugin
/usr/lib/gcc/i686-linux-gnu/11/liblto_plugin.so
-plugin-opt=/usr/lib/gcc/i686-linux-gnu/11/lto-wrapper
-plugin-opt=-fresolution=507.res -plugin-

[Bug target/106165] incorrect result when using inlined asm implementation of floor() on i686

2022-07-01 Thread xeioexception at gmail dot com via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106165

--- Comment #1 from xeioex  ---
TO fix the last confirmations

1) gcc -O2  minified_to_string_radix.i -o 507 -lm && ./507
1e+23.toString(36) = ga894a06ac8
ERROR expected "ga894a06abs"

2) gcc -O1  minified_to_string_radix.i -o 507 -lm && ./507
1e+23.toString(36) = ga894a06abs
OK

3) gcc -O1 -ffast-math minified_to_string_radix.i -o 507 -lm && ./507
1e+23.toString(36) = ga894a06abs
OK

4) gcc -O1 -fstrict-aliasing minified_to_string_radix.i -o 507 -lm && ./507
1e+23.toString(36) = ga894a06abs
OK 

5) removing inlined floor() fixed the issue

6) clang-6.0  -O2  minified_to_string_radix.i -o 507 -lm && ./507
1e+23.toString(36) = ga894a06abs

[Bug target/106165] incorrect result when using inlined asm implementation of floor() on i686

2022-07-05 Thread xeioexception at gmail dot com via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106165

--- Comment #3 from xeioex  ---
Is there a portable (across platforms and compilers) to ensure that double
values are always 64 bits?

[Bug target/106165] incorrect result when using inlined asm implementation of floor() on i686

2022-07-05 Thread xeioexception at gmail dot com via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106165

--- Comment #5 from xeioex  ---
My question is more practical. For example while `-fexcess-precision=standard`
fixes the problem in GCC. But, I am left with the same problem regarding other
compilers. At least am looking for a way to detect excessive precision as soon
as possible (during configure time).

Tried to use FLT_EVAL_METHOD

t.c
```
#include 
#include 
#include 
#include 

int main(){
  printf("%d\n", (int) FLT_EVAL_METHOD);
}
```

1) gcc -o t t.c && ./t
2

2) gcc -fexcess-precision=standard -o t t.c && ./t
2


How am I expected to use FLT_EVAL_METHOD correctly?