forked from OSchip/llvm-project
dfd14adeb0
Summary:
Two utils methods have essentially the same functionality. This is an attempt to merge them into one.
1. lib/Transforms/Utils/Local.cpp : MergeBasicBlockIntoOnlyPred
2. lib/Transforms/Utils/BasicBlockUtils.cpp : MergeBlockIntoPredecessor
Prior to the patch:
1. MergeBasicBlockIntoOnlyPred
Updates either DomTree or DeferredDominance
Moves all instructions from Pred to BB, deletes Pred
Asserts BB has single predecessor
If address was taken, replace the block address with constant 1 (?)
2. MergeBlockIntoPredecessor
Updates DomTree, LoopInfo and MemoryDependenceResults
Moves all instruction from BB to Pred, deletes BB
Returns if doesn't have a single predecessor
Returns if BB's address was taken
After the patch:
Method 2. MergeBlockIntoPredecessor is attempting to become the new default:
Updates DomTree or DeferredDominance, and LoopInfo and MemoryDependenceResults
Moves all instruction from BB to Pred, deletes BB
Returns if doesn't have a single predecessor
Returns if BB's address was taken
Uses of MergeBasicBlockIntoOnlyPred that need to be replaced:
1. lib/Transforms/Scalar/LoopSimplifyCFG.cpp
Updated in this patch. No challenges.
2. lib/CodeGen/CodeGenPrepare.cpp
Updated in this patch.
i. eliminateFallThrough is straightforward, but I added using a temporary array to avoid the iterator invalidation.
ii. eliminateMostlyEmptyBlock(s) methods also now use a temporary array for blocks
Some interesting aspects:
- Since Pred is not deleted (BB is), the entry block does not need updating.
- The entry block was being updated with the deleted block in eliminateMostlyEmptyBlock. Added assert to make obvious that BB=SinglePred.
- isMergingEmptyBlockProfitable assumes BB is the one to be deleted.
- eliminateMostlyEmptyBlock(BB) does not delete BB on one path, it deletes its unique predecessor instead.
- adding some test owner as subscribers for the interesting tests modified:
test/CodeGen/X86/avx-cmp.ll
test/CodeGen/AMDGPU/nested-loop-conditions.ll
test/CodeGen/AMDGPU/si-annotate-cf.ll
test/CodeGen/X86/hoist-spill.ll
test/CodeGen/X86/2006-11-17-IllegalMove.ll
3. lib/Transforms/Scalar/JumpThreading.cpp
Not covered in this patch. It is the only use case using the DeferredDominance.
I would defer to Brian Rzycki to make this replacement.
Reviewers: chandlerc, spatel, davide, brzycki, bkramer, javed.absar
Subscribers: qcolombet, sanjoy, nemanjai, nhaehnle, jlebar, tpr, kbarton, RKSimon, wmi, arsenm, llvm-commits
Differential Revision: https://reviews.llvm.org/D48202
llvm-svn: 335183
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| .. | ||
| AArch64 | ||
| AMDGPU | ||
| ARM | ||
| NVPTX | ||
| X86 | ||
| 2005-08-15-AddRecIV.ll | ||
| 2005-08-17-OutOfLoopVariant.ll | ||
| 2005-09-12-UsesOutOutsideOfLoop.ll | ||
| 2007-04-23-UseIterator.ll | ||
| 2008-08-13-CmpStride.ll | ||
| 2008-09-09-Overflow.ll | ||
| 2009-01-13-nonconstant-stride-outside-loop.ll | ||
| 2009-04-28-no-reduce-mul.ll | ||
| 2011-07-19-CritEdgeBreakCrash.ll | ||
| 2011-10-03-CritEdgeMerge.ll | ||
| 2011-10-06-ReusePhi.ll | ||
| 2011-10-13-SCEVChain.ll | ||
| 2011-10-14-IntPtr.ll | ||
| 2011-12-19-PostincQuadratic.ll | ||
| 2012-01-02-nopreheader.ll | ||
| 2012-01-16-nopreheader.ll | ||
| 2012-03-15-nopreheader.ll | ||
| 2012-03-26-constexpr.ll | ||
| 2012-07-13-ExpandUDiv.ll | ||
| 2012-07-18-LimitReassociate.ll | ||
| 2013-01-05-IndBr.ll | ||
| 2013-01-14-ReuseCast.ll | ||
| addrec-gep-address-space.ll | ||
| addrec-gep.ll | ||
| address-space-loop.ll | ||
| count-to-zero.ll | ||
| dead-phi.ll | ||
| different-type-ivs.ll | ||
| dominate-assert.ll | ||
| dont-hoist-simple-loop-constants.ll | ||
| dont_insert_redundant_ops.ll | ||
| dont_reduce_bytes.ll | ||
| dont_reverse.ll | ||
| ephemeral.ll | ||
| exit_compare_live_range.ll | ||
| funclet.ll | ||
| hoist-parent-preheader.ll | ||
| illegal-addr-modes.ll | ||
| invariant_value_first.ll | ||
| invariant_value_first_arg.ll | ||
| ivchain.ll | ||
| lsr-comp-time.ll | ||
| negative-scale.ll | ||
| nested-reduce.ll | ||
| nonintegral.ll | ||
| nonlinear-postinc.ll | ||
| ops_after_indvar.ll | ||
| phi_node_update_multiple_preds.ll | ||
| post-inc-icmpzero.ll | ||
| post-inc-optsize.ll | ||
| pr2537.ll | ||
| pr2570.ll | ||
| pr3086.ll | ||
| pr3399.ll | ||
| pr3571.ll | ||
| pr12018.ll | ||
| pr12048.ll | ||
| pr12691.ll | ||
| pr18165.ll | ||
| pr25541.ll | ||
| pr27056.ll | ||
| pr31627.ll | ||
| preserve-gep-loop-variant.ll | ||
| related_indvars.ll | ||
| remove_indvar.ll | ||
| scaling_factor_cost_crash.ll | ||
| scev-insertpt-bug.ll | ||
| sext-ind-var.ll | ||
| share_code_in_preheader.ll | ||
| share_ivs.ll | ||
| shl.ll | ||
| uglygep-address-space.ll | ||
| uglygep.ll | ||
| use_postinc_value_outside_loop.ll | ||
| var_stride_used_by_compare.ll | ||
| variable_stride.ll | ||