[Bug c++/66239] Unoptimized sqrt(float or double) returns wrong values for ARM Cortex-A8 -mfloat-abi=[soft,softfp]

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66239

ktkachov at gcc dot gnu.org changed:

           What    |Removed                     |Added
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                 CC|                            |ktkachov at gcc dot gnu.org

--- Comment #3 from ktkachov at gcc dot gnu.org ---
FWIW I can't reproduce on a bare-metal arm-none-eabi trunk (i.e. future GCC 6)
With: -mcpu=cortex-a8 -march=armv7-a -mtune=cortex-a8 -mfpu=neon
-mthumb-interwork -mfpu=neon -Wall -Wextra -mfloat-abi=soft prsqrt.c
-specs=rdimon.specs -lm

I get:
3.016621
3.016621
3.016621
3.016621

Note that I also had to add -lm to link the sqrt and sqrtf functions in.
Considering that the -O0 version is the only one that ends up calling the
library functions, perhaps there's something wrong with your math library?
I'm using newlib for arm-none-eabi