search for: d12082

Hello LLVM, A recent commit creates the isIntDivCheap() target query. http://reviews.llvm.org/D12082 The current approach has a couple shortcomings. First, when targets decide divide is cheap, the DAGCombiner ignores obvious power-of-2 optimizations. In the targets I know, shifts are cheaper than divides in both speed and size. The target cannot see the value in the isIntDivCheap() call, so ca...

> On Aug 20, 2015, at 10:22 AM, escha <escha at apple.com> wrote: > >> >> On Aug 20, 2015, at 9:59 AM, Mehdi Amini <mehdi.amini at apple.com <mailto:mehdi.amini at apple.com>> wrote: >> >>> >>> On Aug 20, 2015, at 9:46 AM, Steve King <steve at metrokings.com <mailto:steve at metrokings.com>> wrote: >>>

> On Aug 19, 2015, at 3:48 PM, escha via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > >> On Aug 19, 2015, at 1:45 PM, Steve King via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> >> In the targets I know, shifts are >> cheaper than divides in both speed and size. > > From what I remember, udiv by

> On Aug 20, 2015, at 9:46 AM, Steve King <steve at metrokings.com> wrote: > > On Wed, Aug 19, 2015 at 10:58 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: >> >> Isn’t the problem the fact that the patch makes it harder for a target to >> get the generic code to reach its custom hook? >> Now the "cheap pow2 sdiv” is merged with the generic