Displaying 2 results from an estimated 2 matches for "assume_no_signed_zero".
2010 Jan 15
0
[LLVMdev] Presenting Unsafe Math Flag to Optimizer
...uld also be useful to know you can do reassociation
> etc, useful to know that you don't care about signed zero, etc.
I think the main issues are:
1) special values (+0, -0, NaN, +Inf, -Inf) to be taken into account
- this can be represented with an 'assume_finite' bit and an
'assume_no_signed_zero' bit
2) rounding, the x86 FPU has 80 bits of internal precision, so you get
inconsistent results depending
on intermediate results being spilled or being kept in registers. One usual
way of handling this is
that any assignment in the source code will truncate to the memory
representation, w...
2010 Jan 14
2
[LLVMdev] Presenting Unsafe Math Flag to Optimizer
On Jan 14, 2010, at 2:01 AM, Duncan Sands wrote:
> Hi Bill,
>
>> The current implementation of the "allow unsafe math" option is to
>> specify it via the TargetOptions object. However, this prevents the
>> target-independent optimizer from using it. Are there any opinions
>> (ha!) on how this could be achieved in a nice clean manner which
>>