Subzero: Initial implementation of BB Local CSE

src/IceInst.h

Index: src/IceInst.h
diff --git a/src/IceInst.h b/src/IceInst.h
index 36b8810a82bcbf0390e66283285f6cde91763239..33d7d436fb80427399a43e134e8ba93691c67f96 100644
--- a/src/IceInst.h
+++ b/src/IceInst.h
@@ -108,6 +108,12 @@ public:
     assert(I < getSrcSize());
     return Srcs[I];
   }
+  void replaceSource(SizeT Index, Operand *Replacement) {
+    assert(Index < NumSrcs);
+    assert(!isDeleted());
+    assert(LiveRangesEnded == 0);

[Jim Stichnoth, 2016/05/24 04:58:11]

Add a brief comment why this assert is needed (the other asserts are clear).

Something like: Try to ensure this is not called after liveness analysis runs,
because last-use info will surely become incorrect.

[manasijm, 2016/05/24 16:54:21]

Done.

+    Srcs[Index] = Replacement;
+  }
 
   bool isLastUse(const Operand *Src) const;
   void spliceLivenessInfo(Inst *OrigInst, Inst *SpliceAssn);