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Re: [Patch-86512]: Subnormal float support in armv7(with -msoft-float) for intrinsics

Umesh Kalappa wrote:

> We tested on the SP and yes the problem persist on the SP too and
> attached patch will fix the both SP and DP issues for the  denormal
> resultant.

The patch now looks correct to me (but I can't approve).

> We bootstrapped the compiler ,look ok to us with minimal testing ,
> Any floating point test-suite to test for the attached patch ? any
> recommendations or inputs  ?

Running the GCC regression tests would be required since a bootstrap isn't 
useful for this kind of change. Assuming you use Linux, building and running
GLIBC with the changed GCC would give additional test coverage as it tests
all the math library functions.

I don't know of any IEEE conformance testsuites in the GNU world, which is
why I'm suggesting running some targeted and randomized tests. You could
use the generic soft-float code in libgcc/soft-fp/adddf3.c to compare the outputs.

>>> Index: libgcc/config/arm/ieee754-df.S
>>> ===================================================================
>>> --- libgcc/config/arm/ieee754-df.S   (revision 262850)
>>> +++ libgcc/config/arm/ieee754-df.S   (working copy)
>>> @@ -203,6 +203,7 @@
>>>  #endif
>>>      @ Determine how to normalize the result.
>>> +    @ if result is denormal i.e (exp)=0,then don't normalise the result,

Use a standard sentence here, eg. like:

If exp is zero and the mantissa unnormalized, return a denormal.


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