Allow null interference cursors to be queried.
They always report 'no interference'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135843 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/InterferenceCache.cpp b/lib/CodeGen/InterferenceCache.cpp
index a09bb39..29b47bd 100644
--- a/lib/CodeGen/InterferenceCache.cpp
+++ b/lib/CodeGen/InterferenceCache.cpp
@@ -18,10 +18,13 @@
using namespace llvm;
+// Static member used for null interference cursors.
+InterferenceCache::BlockInterference InterferenceCache::Cursor::NoInterference;
+
void InterferenceCache::init(MachineFunction *mf,
LiveIntervalUnion *liuarray,
SlotIndexes *indexes,
- const TargetRegisterInfo *tri) {
+ const TargetRegisterInfo *tri) {
MF = mf;
LIUArray = liuarray;
TRI = tri;
diff --git a/lib/CodeGen/InterferenceCache.h b/lib/CodeGen/InterferenceCache.h
index 7f0a27a..4df0a9e 100644
--- a/lib/CodeGen/InterferenceCache.h
+++ b/lib/CodeGen/InterferenceCache.h
@@ -138,6 +138,7 @@
class Cursor {
Entry *CacheEntry;
BlockInterference *Current;
+ static BlockInterference NoInterference;
void setEntry(Entry *E) {
Current = 0;
@@ -175,7 +176,7 @@
/// moveTo - Move cursor to basic block MBBNum.
void moveToBlock(unsigned MBBNum) {
- Current = CacheEntry->get(MBBNum);
+ Current = CacheEntry ? CacheEntry->get(MBBNum) : &NoInterference;
}
/// hasInterference - Return true if the current block has any interference.