Commit Graph
12 Commits
Author SHA1 Message Date
Wei Mi 4db6728b3a [SLP vectorizer]: Choose the best consecutive candidate to pair with a store instruction.
The patch changes the SLPVectorizer::vectorizeStores to choose the immediate
succeeding or preceding candidate for a store instruction when it has multiple
consecutive candidates. In this way it has better chance to find more slp
vectorization opportunities.

Differential Revision: http://reviews.llvm.org/D10445


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243666 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-30 17:40:39 +00:00
Wei Mi d5892380e1 Create a wrapper pass for BlockFrequencyInfo.
This is useful when we want to do block frequency analysis
conditionally (e.g. only in PGO mode) but don't want to add
one more pass dependence.

Patch by congh.
Approved by dexonsmith.
Differential Revision: http://reviews.llvm.org/D11196


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242248 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 23:40:50 +00:00
Wei Mi 61897e8564 Enable exitValue rewrite only when the cost of expansion is low.
The patch evaluates the expansion cost of exitValue in indVarSimplify pass, and only does the rewriting when the expansion cost is low or loop can be deleted with the rewriting. It provides an option "-replexitval=" to control the default aggressiveness of the exitvalue rewriting. It also fixes some missing cases in SCEVExpander::isHighCostExpansionHelper to enhance the evaluation of SCEV expansion cost.

Differential Revision: http://reviews.llvm.org/D9800


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238507 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 21:49:07 +00:00
Wei Mi 51891f2364 Remove the InstructionSimplifierPass immediately after InstructionCombiningPass.
InstructionCombiningPass was added after LoopUnrollPass in r237395. Because
InstructionCombiningPass is strictly more powerful than InstructionSimplifierPass,
remove the unnecessary InstructionSimplifierPass.

Differential Revision: http://reviews.llvm.org/D9838


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237702 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-19 16:09:11 +00:00
Wei Mi 95f7517f1b Add another InstCombine pass after LoopUnroll.
This is to cleanup some redundency generated by LoopUnroll pass. Such redundency may not be cleaned up by existing passes after LoopUnroll.

Differential Revision: http://reviews.llvm.org/D9777


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237395 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-14 22:02:54 +00:00
Wei Mi cac51be31f [X86] Disable loop unrolling in loop vectorization pass when VF is 1.
The patch disabled unrolling in loop vectorization pass when VF==1 on x86 architecture,
by setting MaxInterleaveFactor to 1. Unrolling in loop vectorization pass may introduce
the cost of overflow check, memory boundary check and extra prologue/epilogue code when
regular unroller will unroll the loop another time. Disable it when VF==1 remove the
unnecessary cost on x86. The same can be done for other platforms after verifying
interleaving/memory bound checking to be not perf critical on those platforms.

Differential Revision: http://reviews.llvm.org/D9515


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236613 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-06 17:12:25 +00:00
Wei Mi ef67950b62 Limiting gep merging to fix the performance problem described in
https://llvm.org/bugs/show_bug.cgi?id=23163.

Gep merging sometimes behaves like a reverse CSE/LICM optimization,
which has negative impact on performance. In this patch we restrict
gep merging to happen only when the indexes to be merged are both consts,
which ensures such merge is always beneficial.

The patch makes gep merging only happen in very restrictive cases.
It is possible that some analysis/optimization passes rely on the merged
geps to get better result, and we havn't notice them yet. We will be ready
to further improve it once we see the cases.

Differential Revision: http://reviews.llvm.org/D8911


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235455 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 23:02:15 +00:00
Wei Mi 480fc70c43 Revert r235451 since it is attached to a wrong Differential Revision. Sorry.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235453 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 22:56:09 +00:00
Wei Mi 73a5fa9ad6 Limiting gep merging to fix the performance problem described in
https://llvm.org/bugs/show_bug.cgi?id=23163.

Gep merging sometimes behaves like a reverse CSE/LICM optimizations,
which has negative impact on performance. In this patch we restrict
gep merging to happen only when the indexes to be merged are both consts,
which ensures such merge is always beneficial.

The patch makes gep merging only happen in very restrictive cases.
It is possible that some analysis/optimization passes rely on the merged
geps to get better result, and we havn't notice them yet. We will be ready
to further improve it once we see the cases.

Differential Revision: http://reviews.llvm.org/D9007


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235451 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 22:37:09 +00:00
Wei Mi 8979e3f69b Correctly estimate SROA savings for store operands in inline cost analysis.
When estimating SROA savings, we want to see if an address is derived
off an alloca in the caller. For store instructions, operand 1 is the
address operand, but the current code uses operand 0.  Use
getPointerOperand for loads and stores to fix this.

Patch by Easwaran Raman.
http://reviews.llvm.org/D8425


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232827 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-20 18:33:12 +00:00
Wei Mi a2b8275694 Revert the test commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231264 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-04 17:44:22 +00:00
Wei Mi f1bc8c34cf Test commit. It will be reverted in the next commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231262 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-04 17:41:17 +00:00