stub out a new libanalysis "instruction simplify" interface that

takes decimated instructions and applies identities to them.  This
is pretty minimal at this point, but I plan to pull some instcombine
logic out into these and similar routines.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86613 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 37 insertions, 0 deletions

diff --git a/include/llvm/Analysis/InstructionSimplify.h b/include/llvm/Analysis/InstructionSimplify.h
new file mode 100644
index 0000000000..7d75435575
--- /dev/null
+++ b/include/llvm/Analysis/InstructionSimplify.h
@@ -0,0 +1,37 @@
+//===-- InstructionSimplify.h - Fold instructions into simpler forms ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares routines for folding instructions into simpler forms that
+// do not require creating new instructions.  For example, this does constant
+// folding, and can handle identities like (X&0)->0.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
+#define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
+
+namespace llvm {
+  class Value;
+  class TargetData;
+  
+  /// SimplifyCompare - Given operands for a CmpInst, see if we can
+  /// fold the result.  If not, this returns null.
+  Value *SimplifyCompare(unsigned Predicate, Value *LHS, Value *RHS,
+                         const TargetData *TD = 0);
+  
+  
+  /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
+  /// fold the result.  If not, this returns null.
+  Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, 
+                       const TargetData *TD = 0);
+  
+} // end namespace llvm
+
+#endif
+