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author | Stephen Hines <srhines@google.com> | 2015-03-23 12:10:34 -0700 |
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committer | Stephen Hines <srhines@google.com> | 2015-03-23 12:10:34 -0700 |
commit | ebe69fe11e48d322045d5949c83283927a0d790b (patch) | |
tree | c92f1907a6b8006628a4b01615f38264d29834ea /lib/Analysis/BlockFrequencyInfoImpl.cpp | |
parent | b7d2e72b02a4cb8034f32f8247a2558d2434e121 (diff) | |
download | external_llvm-ebe69fe11e48d322045d5949c83283927a0d790b.zip external_llvm-ebe69fe11e48d322045d5949c83283927a0d790b.tar.gz external_llvm-ebe69fe11e48d322045d5949c83283927a0d790b.tar.bz2 |
Update aosp/master LLVM for rebase to r230699.
Change-Id: I2b5be30509658cb8266be782de0ab24f9099f9b9
Diffstat (limited to 'lib/Analysis/BlockFrequencyInfoImpl.cpp')
-rw-r--r-- | lib/Analysis/BlockFrequencyInfoImpl.cpp | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/lib/Analysis/BlockFrequencyInfoImpl.cpp b/lib/Analysis/BlockFrequencyInfoImpl.cpp index 06b8acd..278073c 100644 --- a/lib/Analysis/BlockFrequencyInfoImpl.cpp +++ b/lib/Analysis/BlockFrequencyInfoImpl.cpp @@ -14,6 +14,7 @@ #include "llvm/Analysis/BlockFrequencyInfoImpl.h" #include "llvm/ADT/SCCIterator.h" #include "llvm/Support/raw_ostream.h" +#include <numeric> using namespace llvm; using namespace llvm::bfi_detail; @@ -122,8 +123,12 @@ static void combineWeight(Weight &W, const Weight &OtherW) { } assert(W.Type == OtherW.Type); assert(W.TargetNode == OtherW.TargetNode); - assert(W.Amount < W.Amount + OtherW.Amount && "Unexpected overflow"); - W.Amount += OtherW.Amount; + assert(OtherW.Amount && "Expected non-zero weight"); + if (W.Amount > W.Amount + OtherW.Amount) + // Saturate on overflow. + W.Amount = UINT64_MAX; + else + W.Amount += OtherW.Amount; } static void combineWeightsBySorting(WeightList &Weights) { // Sort so edges to the same node are adjacent. @@ -206,11 +211,19 @@ void Distribution::normalize() { Shift = 33 - countLeadingZeros(Total); // Early exit if nothing needs to be scaled. - if (!Shift) + if (!Shift) { + // If we didn't overflow then combineWeights() shouldn't have changed the + // sum of the weights, but let's double-check. + assert(Total == std::accumulate(Weights.begin(), Weights.end(), UINT64_C(0), + [](uint64_t Sum, const Weight &W) { + return Sum + W.Amount; + }) && + "Expected total to be correct"); return; + } // Recompute the total through accumulation (rather than shifting it) so that - // it's accurate after shifting. + // it's accurate after shifting and any changes combineWeights() made above. Total = 0; // Sum the weights to each node and shift right if necessary. |