split a complex predicate out to a helper function. Simplify two for loops,
which don't need to check for falling off the end of a block *and* end of phi
nodes, since terminators are never phis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129655 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 4b6066e..2ff46aa 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -830,6 +830,17 @@
}
#endif
+/// isFoldedOrDeadInstruction - Return true if the specified instruction is
+/// side-effect free and is either dead or folded into a generated instruction.
+/// Return false if it needs to be emitted.
+static bool isFoldedOrDeadInstruction(const Instruction *I,
+ FunctionLoweringInfo *FuncInfo) {
+ return !I->mayWriteToMemory() &&
+ !isa<TerminatorInst>(I) &&
+ !isa<DbgInfoIntrinsic>(I) &&
+ !FuncInfo->isExportedInst(I);
+}
+
void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
// Initialize the Fast-ISel state, if needed.
FastISel *FastIS = 0;
@@ -856,15 +867,13 @@
}
if (AllPredsVisited) {
- for (BasicBlock::const_iterator I = LLVMBB->begin(), E = LLVMBB->end();
- I != E && isa<PHINode>(I); ++I) {
+ for (BasicBlock::const_iterator I = LLVMBB->begin();
+ isa<PHINode>(I); ++I)
FuncInfo->ComputePHILiveOutRegInfo(cast<PHINode>(I));
- }
} else {
- for (BasicBlock::const_iterator I = LLVMBB->begin(), E = LLVMBB->end();
- I != E && isa<PHINode>(I); ++I) {
+ for (BasicBlock::const_iterator I = LLVMBB->begin();
+ isa<PHINode>(I); ++I)
FuncInfo->InvalidatePHILiveOutRegInfo(cast<PHINode>(I));
- }
}
FuncInfo->VisitedBBs.insert(LLVMBB);
@@ -912,10 +921,7 @@
const Instruction *Inst = llvm::prior(BI);
// If we no longer require this instruction, skip it.
- if (!Inst->mayWriteToMemory() &&
- !isa<TerminatorInst>(Inst) &&
- !isa<DbgInfoIntrinsic>(Inst) &&
- !FuncInfo->isExportedInst(Inst))
+ if (isFoldedOrDeadInstruction(Inst, FuncInfo))
continue;
// Bottom-up: reset the insert pos at the top, after any local-value