Bob Wilson 674598a72c Reapply my if-conversion cleanup from svn r106939 with fixes. ... There are 2 changes relative to the previous version of the patch: 1) For the "simple" if-conversion case, there's no need to worry about RemoveExtraEdges not handling an unanalyzable branch. Predicated terminators are ignored in this context, so RemoveExtraEdges does the right thing. This might break someday if we ever treat indirect branches (BRIND) as predicable, but for now, I just removed this part of the patch, because in the case where we do not add an unconditional branch, we rely on keeping the fall-through edge to CvtBBI (which is empty after this transformation). The change relative to the previous patch is: @@ -1036,10 +1036,6 @@ IterIfcvt = false; } - // RemoveExtraEdges won't work if the block has an unanalyzable branch, - // which is typically the case for IfConvertSimple, so explicitly remove - // CvtBBI as a successor. - BBI.BB->removeSuccessor(CvtBBI->BB); RemoveExtraEdges(BBI); // Update block info. BB can be iteratively if-converted. 2) My patch exposed a bug in the code for merging the tail of a "diamond", which had previously never been exercised. The code was simply checking that the tail had a single predecessor, but there was a case in MultiSource/Benchmarks/VersaBench/dbms where that single predecessor was neither edge of the diamond. I added the following change to check for that: @@ -1276,7 +1276,18 @@ // tail, add a unconditional branch to it. if (TailBB) { BBInfo TailBBI = BBAnalysis[TailBB->getNumber()]; - if (TailBB->pred_size() == 1 && !TailBBI.HasFallThrough) { + bool CanMergeTail = !TailBBI.HasFallThrough; + // There may still be a fall-through edge from BBI1 or BBI2 to TailBB; + // check if there are any other predecessors besides those. + unsigned NumPreds = TailBB->pred_size(); + if (NumPreds > 1) + CanMergeTail = false; + else if (NumPreds == 1 && CanMergeTail) { + MachineBasicBlock::pred_iterator PI = TailBB->pred_begin(); + if (*PI != BBI1->BB && *PI != BBI2->BB) + CanMergeTail = false; + } + if (CanMergeTail) { MergeBlocks(BBI, TailBBI); TailBBI.IsDone = true; } else { With these fixes, I was able to run all the SingleSource and MultiSource tests successfully. llvm-svn: 107110		2010-06-29 00:55:23 +00:00
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Alpha	Split big test into multiple directories to cater to	2010-04-07 20:43:35 +00:00
ARM	Unlike other targets, ARM now uses BUILD_VECTORs post-legalization so they	2010-06-28 23:40:25 +00:00
Blackfin	Start function numbering at 0.	2010-04-17 16:29:15 +00:00
CBackend
CellSPU	Fix some tests that didn't test anything.	2010-06-26 20:05:06 +00:00
CPP	fix PR5295 where the .ll parser didn't reject a function after a global	2009-10-25 23:22:50 +00:00
Generic	Move v-binop-widen tests to X86 since they don't work on all platforms	2010-06-22 19:40:50 +00:00
MBlaze	Split big test into multiple directories to cater to	2010-04-07 20:43:35 +00:00
Mips	Start function numbering at 0.	2010-04-17 16:29:15 +00:00
MSP430	Insert ANY_EXTEND node instead of invalid truncate during DAG Combining (X & 1),	2010-05-01 12:52:34 +00:00
PIC16	Remove XFAIL for vg_leak as the leaks are fixed by 100601.	2010-04-07 07:06:48 +00:00
PowerPC	Eliminate the other half of the BRCOND optimization, and update	2010-06-24 15:24:03 +00:00
SPARC	Split big test into multiple directories to cater to	2010-04-07 20:43:35 +00:00
SystemZ	SystemZ really does mean "has calls" and not just "adjusts stack." Go ahead and	2010-05-14 22:17:42 +00:00
Thumb	Fix some tests that didn't test anything.	2010-06-26 20:05:06 +00:00
Thumb2	Reapply my if-conversion cleanup from svn r106939 with fixes.	2010-06-29 00:55:23 +00:00
X86	In asm's, output operands with matching input constraints	2010-06-28 22:09:45 +00:00
XCore	Start function numbering at 0.	2010-04-17 16:29:15 +00:00