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.
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))