search for: tailbb

Hi all, I have faced a little bit of a strange transformation from the TailDuplicatePass In CodeGen. When the pass clones the contents of TailBB into PredBB, the bundled instructions in TailBB are not bundled in PredBB. I think the reason why it is not bundled is that the 'DuplicateInstruction' function does not set up the flag of the first instruction of the bundle in PredBB when it is cloned from TailBB. If the first instructi...

On Tue, Oct 10, 2017 at 4:48 PM, Friedman, Eli via llvm-dev < llvm-dev at lists.llvm.org> wrote: > On 10/9/2017 3:10 AM, Gaël Jobin via llvm-dev wrote: > > Hi all, > > I got a silly bug when compiling our project with the latest Clang. Here's > the outputted assembly: > > tst r3, #255 > strbeq r6, [r7] > ldreq r6, [r4, r6, lsl #2] > strne r6, [r7, #4]

...;m not sure what the best way of dealing with this is. Should AnalyzeBranch be enhanced to somehow indicate conditional returns? Alternatively, the diamond conversion routine contains this: // RemoveExtraEdges won't work if the block has an unanalyzable branch, // which can happen here if TailBB is unanalyzable and is merged, so // explicitly remove BBI1 and BBI2 as successors. BBI.BB->removeSuccessor(BBI1->BB); BBI.BB->removeSuccessor(BBI2->BB); RemoveExtraEdges(BBI); should something similar be added prior to the calls to RemoveExtraEdges in the simple and triangle c...

...t think that returns can ever be analyzable (since LLVM's CFG does not have a designated exit block). > Alternatively, the diamond conversion routine contains this: > > // RemoveExtraEdges won't work if the block has an unanalyzable branch, > // which can happen here if TailBB is unanalyzable and is merged, so > // explicitly remove BBI1 and BBI2 as successors. > BBI.BB->removeSuccessor(BBI1->BB); > BBI.BB->removeSuccessor(BBI2->BB); > RemoveExtraEdges(BBI); > > should something similar be added prior to the calls to RemoveExtraE...