Displaying 6 results from an estimated 6 matches for "simplifydemandedinstructionbit".
Did you mean:
simplifydemandedinstructionbits
2009 Jul 29
3
[LLVMdev] Vector logic regression in r73431
...se a logic operation is attempted
between a vector and a scalar (which is not present in the original code,
but created by InstCombine).
It's caused by revision 73431. I was able to fix it by changing the
following (identical) lines in InstCombiner::visitAnd, visitOr and visitXor:
if (SimplifyDemandedInstructionBits(I))
return &I;
Into:
if (!isa<VectorType>(I.getType()) && SimplifyDemandedInstructionBits(I))
return &I;
Apparently SimplifyDemandedInstructionBits doesn't work correctly with
vector operands, sometimes replacing them with a scalar value?
So co...
2017 Mar 20
2
Saving Compile Time in InstCombine
...t 6:12 PM, David Majnemer <david.majnemer at gmail.com> wrote:
>
> Honestly, I'm not a huge fan of this change as-is. The set of transforms that were added behind ExpensiveChecks seems awfully strange and many would not lead the reader to believe that they are expensive at all (the SimplifyDemandedInstructionBits and foldICmpUsingKnownBits calls being the obvious expensive routines).
>
> The purpose of many of InstCombine's xforms is to canonicalize the IR to make life easier for downstream passes and analyses.
OK, but is it true of *all* the combines today?
>
> InstCombine internally r...
2017 Mar 18
4
Saving Compile Time in InstCombine
On 03/17/2017 04:30 PM, Mehdi Amini via llvm-dev wrote:
>
>> On Mar 17, 2017, at 11:50 AM, Mikhail Zolotukhin via llvm-dev
>> <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>>
>> Hi,
>>
>> One of the most time-consuming passes in LLVM middle-end is
>> InstCombine (see e.g. [1]). It is a very powerful pass capable
2017 Mar 21
2
Saving Compile Time in InstCombine
...avid Majnemer via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>
> Honestly, I'm not a huge fan of this change as-is. The set of transforms that were added behind ExpensiveChecks seems awfully strange and many would not lead the reader to believe that they are expensive at all (the SimplifyDemandedInstructionBits and foldICmpUsingKnownBits calls being the obvious expensive routines).
>
> The purpose of many of InstCombine's xforms is to canonicalize the IR to make life easier for downstream passes and analyses.
As we get further along with compile-time improvements one question we need to ask o...
2017 Mar 22
3
Saving Compile Time in InstCombine
...vm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> Honestly, I'm not a huge fan of this change as-is. The set of transforms
> that were added behind ExpensiveChecks seems awfully strange and many would
> not lead the reader to believe that they are expensive at all
> (the SimplifyDemandedInstructionBits and foldICmpUsingKnownBits calls
> being the obvious expensive routines).
>
> The purpose of many of InstCombine's xforms is to canonicalize the IR to
> make life easier for downstream passes and analyses.
>
>
> As we get further along with compile-time improvements one qu...
2017 Mar 23
2
Saving Compile Time in InstCombine
...to:llvm-dev at lists.llvm.org>> wrote:
>>>>
>>>> Honestly, I'm not a huge fan of this change as-is. The set of transforms that were added behind ExpensiveChecks seems awfully strange and many would not lead the reader to believe that they are expensive at all (the SimplifyDemandedInstructionBits and foldICmpUsingKnownBits calls being the obvious expensive routines).
>>>>
>>>> The purpose of many of InstCombine's xforms is to canonicalize the IR to make life easier for downstream passes and analyses.
>>>
>>> As we get further along with compi...