Add a getFirstNonPHI utility function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107778 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index dcbcb25..3cfc47a 100644
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -282,6 +282,13 @@
/// branch to do so (e.g., a table jump). True is a conservative answer.
bool canFallThrough();
+ /// Returns a pointer to the first instructon in this block that is not a
+ /// PHINode instruction. When adding instruction to the beginning of the
+ /// basic block, they should be added before the returned value, not before
+ /// the first instruction, which might be PHI.
+ /// Returns end() is there's no non-PHI instruction.
+ iterator getFirstNonPHI();
+
/// getFirstTerminator - returns an iterator to the first terminator
/// instruction of this basic block. If a terminator does not exist,
/// it returns end()
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index dee4786..a27ee47 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -139,6 +139,13 @@
Parent->getParent()->DeleteMachineInstr(MI);
}
+MachineBasicBlock::iterator MachineBasicBlock::getFirstNonPHI() {
+ iterator I = begin();
+ while (I != end() && I->isPHI())
+ ++I;
+ return I;
+}
+
MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() {
iterator I = end();
while (I != begin() && (--I)->getDesc().isTerminator())