diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/GVNHoist.cpp | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/GVNHoist.cpp b/llvm/lib/Transforms/Scalar/GVNHoist.cpp index 5a50f54cf5f..245fef986a3 100644 --- a/llvm/lib/Transforms/Scalar/GVNHoist.cpp +++ b/llvm/lib/Transforms/Scalar/GVNHoist.cpp @@ -48,6 +48,11 @@ static cl::opt<int> MaxNumberOfBBSInPath( cl::desc("Max number of basic blocks on the path between " "hoisting locations (default = 4, unlimited = -1)")); +static cl::opt<int> MaxDepthInBB( + "gvn-hoist-max-depth", cl::Hidden, cl::init(100), + cl::desc("Hoist instructions from the beginning of the BB up to the " + "maximum specified depth (default = 100, unlimited = -1)")); + namespace { // Provides a sorting function based on the execution order of two instructions. @@ -765,7 +770,13 @@ private: StoreInfo SI; CallInfo CI; for (BasicBlock *BB : depth_first(&F.getEntryBlock())) { + int InstructionNb = 0; for (Instruction &I1 : *BB) { + // Only hoist the first instructions in BB up to MaxDepthInBB. Hoisting + // deeper may increase the register pressure and compilation time. + if (MaxDepthInBB != -1 && InstructionNb++ >= MaxDepthInBB) + break; + if (auto *Load = dyn_cast<LoadInst>(&I1)) LI.insert(Load, VN); else if (auto *Store = dyn_cast<StoreInst>(&I1)) |
