[llvm] r191122 - LoopVectorizer: Only allow vectorization of intrinsics. We can't know for sure that the functions 'abs' or 'round' are the functions from libm.

[Arnold Schwaighofer]

Committed as 191206

On Sep 23, 2013, at 1:03 AM, Nadav Rotem <nrotem at apple.com> wrote:

> Hi Arnold, Ben, Hal, 
> 
> Sorry for the delay in response. Thanks for reviewing my commit. I wanted to fix a case where we crash on a local function with the same name as one of the functions that we vectorize, but with different parameters. I understand that disabling all non-intrinsic functions is too restrictive.  I like Arnold’s solution of checking for internal linkage and validating the parameters. The patch looks excellent. 
> 
> Thanks,
> Nadav
> 
> 
> On Sep 21, 2013, at 4:19 PM, Hal Finkel <hfinkel at anl.gov> wrote:
> 
>> ----- Original Message -----
>>> 
>>> On Sep 21, 2013, at 5:41 PM, Hal Finkel <hfinkel at anl.gov> wrote:
>>> 
>>>> Arnold,
>>>> 
>>>> Thanks for looking at this quickly.
>>>> 
>>>> +static Intrinsic::ID checkBinaryFloatSignature(const CallInst &I,
>>>> +                                               Intrinsic::ID
>>>> ValidIntrinsicID) {
>>>> +  if (I.getNumArgOperands() != 2 ||
>>>> +      !I.getArgOperand(0)->getType()->isFloatingPointTy() ||
>>>> +      !I.getArgOperand(1)->getType()->isFloatingPointTy() ||
>>>> +      I.getType() != I.getArgOperand(0)->getType() ||
>>>> +      !I.onlyReadsMemory())
>>>> +    return Intrinsic::not_intrinsic;
>>>> +
>>>> +  return ValidIntrinsicID;
>>>> +}
>>>> 
>>>> To be pedantic, we should check that the two arguments also have
>>>> the same type (to prevent grabbing copysign(float, double)).
>>> 
>>> Right.
>>> 
>>> Now with
>>> 
>>> +static Intrinsic::ID checkBinaryFloatSignature(const CallInst &I,
>>> +                                               Intrinsic::ID
>>> ValidIntrinsicID)
>>> +  if (I.getNumArgOperands() != 2 ||
>>> +      !I.getArgOperand(0)->getType()->isFloatingPointTy() ||
>>> +      !I.getArgOperand(1)->getType()->isFloatingPointTy() ||
>>> +      I.getType() != I.getArgOperand(0)->getType() ||
>>> +      I.getType() != I.getArgOperand(1)->getType() ||
>>> +      !I.onlyReadsMemory())
>>> 
>> 
>> You might be waiting for Nadav to approve, but LGTM, thanks!
>> 
>> -Hal
>> 
>>> 
>> 
>> -- 
>> Hal Finkel
>> Assistant Computational Scientist
>> Leadership Computing Facility
>> Argonne National Laboratory
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>