Add a flag to indicate that an instruction is as cheap (or cheaper) than a move

instruction to execute. This can be used for transformations (like two-address
conversion) to remat an instruction instead of generating a "move"
instruction. The idea is to decrease the live ranges and register pressure and
all that jazz.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51660 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 1 deletions

diff --git a/utils/TableGen/CodeGenInstruction.h b/utils/TableGen/CodeGenInstruction.h
index 9bfd4323f9..0727e38c53 100644
--- a/utils/TableGen/CodeGenInstruction.h
+++ b/utils/TableGen/CodeGenInstruction.h
@@ -102,7 +102,10 @@ namespace llvm {
     bool hasCtrlDep;
     bool isNotDuplicable;
     bool hasOptionalDef;
-    bool hasSideEffects, mayHaveSideEffects, neverHasSideEffects;
+    bool hasSideEffects;
+    bool mayHaveSideEffects;
+    bool neverHasSideEffects;
+    bool isAsCheapAsAMove;
     
     /// ParseOperandName - Parse an operand name like "$foo" or "$foo.bar",
     /// where $foo is a whole operand and $foo.bar refers to a suboperand.