ARM64: Combine shifts and uses from different basic block to bit-extract instruction

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206774 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 17 insertions, 0 deletions

diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 2e4956f16d..c17416dfee 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -182,6 +182,9 @@ public:
     return HasMultipleConditionRegisters;
   }
 
+  /// Return true if the target has BitExtract instructions.
+  bool hasExtractBitsInsn() const { return HasExtractBitsInsn; }
+
   /// Return true if a vector of the given type should be split
   /// (TypeSplitVector) instead of promoted (TypePromoteInteger) during type
   /// legalization.
@@ -1010,6 +1013,14 @@ protected:
     HasMultipleConditionRegisters = hasManyRegs;
   }
 
+  /// Tells the code generator that the target has BitExtract instructions.
+  /// The code generator will aggressively sink "shift"s into the blocks of
+  /// their users if the users will generate "and" instructions which can be
+  /// combined with "shift" to BitExtract instructions.
+  void setHasExtractBitsInsn(bool hasExtractInsn = true) {
+    HasExtractBitsInsn = hasExtractInsn;
+  }
+
   /// Tells the code generator not to expand sequence of operations into a
   /// separate sequences that increases the amount of flow control.
   void setJumpIsExpensive(bool isExpensive = true) {
@@ -1436,6 +1447,12 @@ private:
   /// the blocks of their users.
   bool HasMultipleConditionRegisters;
 
+  /// Tells the code generator that the target has BitExtract instructions.
+  /// The code generator will aggressively sink "shift"s into the blocks of
+  /// their users if the users will generate "and" instructions which can be
+  /// combined with "shift" to BitExtract instructions.
+  bool HasExtractBitsInsn;
+
   /// Tells the code generator not to expand integer divides by constants into a
   /// sequence of muls, adds, and shifts.  This is a hack until a real cost
   /// model is in place.  If we ever optimize for size, this will be set to true