diff options
| -rw-r--r-- | llvm/lib/Transforms/IPO/SampleProfile.cpp | 38 | ||||
| -rw-r--r-- | llvm/test/Transforms/SampleProfile/fnptr.ll | 8 |
2 files changed, 30 insertions, 16 deletions
diff --git a/llvm/lib/Transforms/IPO/SampleProfile.cpp b/llvm/lib/Transforms/IPO/SampleProfile.cpp index 33239bf5200..af86df798e8 100644 --- a/llvm/lib/Transforms/IPO/SampleProfile.cpp +++ b/llvm/lib/Transforms/IPO/SampleProfile.cpp @@ -812,23 +812,31 @@ bool SampleProfileLoader::propagateThroughEdges(Function &F) { // edge is unknown (see setEdgeOrBlockWeight). for (unsigned i = 0; i < 2; i++) { uint64_t TotalWeight = 0; - unsigned NumUnknownEdges = 0; - Edge UnknownEdge, SelfReferentialEdge; + unsigned NumUnknownEdges = 0, NumTotalEdges = 0; + Edge UnknownEdge, SelfReferentialEdge, SingleEdge; if (i == 0) { // First, visit all predecessor edges. + NumTotalEdges = Predecessors[BB].size(); for (auto *Pred : Predecessors[BB]) { Edge E = std::make_pair(Pred, BB); TotalWeight += visitEdge(E, &NumUnknownEdges, &UnknownEdge); if (E.first == E.second) SelfReferentialEdge = E; } + if (NumTotalEdges == 1) { + SingleEdge = std::make_pair(Predecessors[BB][0], BB); + } } else { // On the second round, visit all successor edges. + NumTotalEdges = Successors[BB].size(); for (auto *Succ : Successors[BB]) { Edge E = std::make_pair(BB, Succ); TotalWeight += visitEdge(E, &NumUnknownEdges, &UnknownEdge); } + if (NumTotalEdges == 1) { + SingleEdge = std::make_pair(BB, Successors[BB][0]); + } } // After visiting all the edges, there are three cases that we @@ -857,18 +865,24 @@ bool SampleProfileLoader::propagateThroughEdges(Function &F) { if (NumUnknownEdges <= 1) { uint64_t &BBWeight = BlockWeights[EC]; if (NumUnknownEdges == 0) { - // If we already know the weight of all edges, the weight of the - // basic block can be computed. It should be no larger than the sum - // of all edge weights. - if (TotalWeight > BBWeight) { - BBWeight = TotalWeight; + if (!VisitedBlocks.count(EC)) { + // If we already know the weight of all edges, the weight of the + // basic block can be computed. It should be no larger than the sum + // of all edge weights. + if (TotalWeight > BBWeight) { + BBWeight = TotalWeight; + Changed = true; + DEBUG(dbgs() << "All edge weights for " << BB->getName() + << " known. Set weight for block: "; + printBlockWeight(dbgs(), BB);); + } + } else if (NumTotalEdges == 1 && + EdgeWeights[SingleEdge] < BlockWeights[EC]) { + // If there is only one edge for the visited basic block, use the + // block weight to adjust edge weight if edge weight is smaller. + EdgeWeights[SingleEdge] = BlockWeights[EC]; Changed = true; - DEBUG(dbgs() << "All edge weights for " << BB->getName() - << " known. Set weight for block: "; - printBlockWeight(dbgs(), BB);); } - if (VisitedBlocks.insert(EC).second) - Changed = true; } else if (NumUnknownEdges == 1 && VisitedBlocks.count(EC)) { // If there is a single unknown edge and the block has been // visited, then we can compute E's weight. diff --git a/llvm/test/Transforms/SampleProfile/fnptr.ll b/llvm/test/Transforms/SampleProfile/fnptr.ll index 540ddbd79c9..b41fec7aed1 100644 --- a/llvm/test/Transforms/SampleProfile/fnptr.ll +++ b/llvm/test/Transforms/SampleProfile/fnptr.ll @@ -10,10 +10,10 @@ ; CHECK: edge for.body3 -> if.then probability is 0x1a4f3959 / 0x80000000 = 20.55% ; CHECK: edge for.body3 -> if.else probability is 0x65b0c6a7 / 0x80000000 = 79.45% -; CHECK: edge for.inc -> for.inc12 probability is 0x33d4a4c1 / 0x80000000 = 40.49% -; CHECK: edge for.inc -> for.body3 probability is 0x4c2b5b3f / 0x80000000 = 59.51% -; CHECK: edge for.inc12 -> for.end14 probability is 0x3f06d04e / 0x80000000 = 49.24% -; CHECK: edge for.inc12 -> for.cond1.preheader probability is 0x40f92fb2 / 0x80000000 = 50.76% +; CHECK: edge for.inc -> for.inc12 probability is 0x20dc8dc9 / 0x80000000 = 25.67% +; CHECK: edge for.inc -> for.body3 probability is 0x5f237237 / 0x80000000 = 74.33% +; CHECK: edge for.inc12 -> for.end14 probability is 0x00000000 / 0x80000000 = 0.00% +; CHECK: edge for.inc12 -> for.cond1.preheader probability is 0x80000000 / 0x80000000 = 100.00% ; Original C++ test case. ; |
