Quick look-up for block in loop.
This patch implements quick look-up for block in loop by maintaining a hash set for blocks.
It improves the efficiency of loop analysis a lot, the biggest improvement could be 5-6%(458.sjeng).
Below are the compilation time for our benchmark in llc before & after the patch.
Benchmark llc - trunk llc - patched
401.bzip2 0.339081 100.00% 0.329657 102.86%
403.gcc 19.853966 100.00% 19.605466 101.27%
429.mcf 0.049823 100.00% 0.048451 102.83%
433.milc 0.514898 100.00% 0.510217 100.92%
444.namd 1.109328 100.00% 1.103481 100.53%
445.gobmk 4.988028 100.00% 4.929114 101.20%
456.hmmer 0.843871 100.00% 0.825865 102.18%
458.sjeng 0.754238 100.00% 0.714095 105.62%
464.h264ref 2.9668 100.00% 2.90612 102.09%
471.omnetpp 4.556533 100.00% 4.511886 100.99%
bitmnp01 0.038168 100.00% 0.0357 106.91%
idctrn01 0.037745 100.00% 0.037332 101.11%
libquake2 3.78689 100.00% 3.76209 100.66%
libquake_ 2.251525 100.00% 2.234104 100.78%
linpack 0.033159 100.00% 0.032788 101.13%
matrix01 0.045319 100.00% 0.043497 104.19%
nbench 0.333161 100.00% 0.329799 101.02%
tblook01 0.017863 100.00% 0.017666 101.12%
ttsprk01 0.054337 100.00% 0.053057 102.41%
Reviewer : Andrew Trick <atrick@apple.com>, Hal Finkel <hfinkel@anl.gov>
Approver : Andrew Trick <atrick@apple.com>
Test : Pass make check-all & llvm test-suite
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193460 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp
index 2d1b166..f15e8d5 100644
--- a/lib/Transforms/Utils/LCSSA.cpp
+++ b/lib/Transforms/Utils/LCSSA.cpp
@@ -55,7 +55,6 @@
DominatorTree *DT;
LoopInfo *LI;
ScalarEvolution *SE;
- std::vector<BasicBlock*> LoopBlocks;
PredIteratorCache PredCache;
Loop *L;
@@ -82,11 +81,6 @@
// Check the special guarantees that LCSSA makes.
assert(L->isLCSSAForm(*DT) && "LCSSA form not preserved!");
}
-
- /// inLoop - returns true if the given block is within the current loop
- bool inLoop(BasicBlock *B) const {
- return std::binary_search(LoopBlocks.begin(), LoopBlocks.end(), B);
- }
};
}
@@ -129,11 +123,6 @@
if (ExitBlocks.empty())
return false;
- // Speed up queries by creating a sorted vector of blocks.
- LoopBlocks.clear();
- LoopBlocks.insert(LoopBlocks.end(), L->block_begin(), L->block_end());
- array_pod_sort(LoopBlocks.begin(), LoopBlocks.end());
-
// Look at all the instructions in the loop, checking to see if they have uses
// outside the loop. If so, rewrite those uses.
bool MadeChange = false;
@@ -198,7 +187,7 @@
if (PHINode *PN = dyn_cast<PHINode>(U))
UserBB = PN->getIncomingBlock(UI);
- if (InstBB != UserBB && !inLoop(UserBB))
+ if (InstBB != UserBB && !L->contains(UserBB))
UsesToRewrite.push_back(&UI.getUse());
}
@@ -244,7 +233,7 @@
// If the exit block has a predecessor not within the loop, arrange for
// the incoming value use corresponding to that predecessor to be
// rewritten in terms of a different LCSSA PHI.
- if (!inLoop(*PI))
+ if (!L->contains(*PI))
UsesToRewrite.push_back(
&PN->getOperandUse(
PN->getOperandNumForIncomingValue(PN->getNumIncomingValues()-1)));