From edb4f7c12a2606f2949b40cec7ec096745d58ad0 Mon Sep 17 00:00:00 2001
From: Quentin Colombet <qcolombet@apple.com>
Date: Wed, 8 Jun 2016 01:11:03 +0000
Subject: [PATCH] [RegisterBankInfo] Add a size argument for the cost of copy.

The cost of a copy may be different based on how many bits we have to
copy around. E.g., a 8-bit copy may be different than a 32-bit copy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272084 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h | 10 +++++++---
 lib/CodeGen/GlobalISel/RegBankSelect.cpp           |  4 +++-
 lib/Target/AArch64/AArch64RegisterBankInfo.cpp     |  3 ++-
 lib/Target/AArch64/AArch64RegisterBankInfo.h       | 10 +++++++---
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h b/include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
index 7ab2fa14a4b..cc2c80d186c 100644
--- a/include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
+++ b/include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
@@ -352,9 +352,13 @@ public:
   }
 
   /// Get the cost of a copy from \p B to \p A, or put differently,
-  /// get the cost of A = COPY B.
-  virtual unsigned copyCost(const RegisterBank &A,
-                            const RegisterBank &B) const {
+  /// get the cost of A = COPY B. Since register banks may cover
+  /// different size, \p Size specifies what will be the size in bits
+  /// that will be copied around.
+  ///
+  /// \note Since this is a copy, both registers have the same size.
+  virtual unsigned copyCost(const RegisterBank &A, const RegisterBank &B,
+                            unsigned Size) const {
     return 0;
   }
 
diff --git a/lib/CodeGen/GlobalISel/RegBankSelect.cpp b/lib/CodeGen/GlobalISel/RegBankSelect.cpp
index fc04f4e8a55..4890d45a6d3 100644
--- a/lib/CodeGen/GlobalISel/RegBankSelect.cpp
+++ b/lib/CodeGen/GlobalISel/RegBankSelect.cpp
@@ -163,7 +163,9 @@ uint64_t RegBankSelect::getRepairCost(
     // the repairing.
     if (MO.isDef())
       std::swap(CurRegBank, DesiredRegBrank);
-    unsigned Cost = RBI->copyCost(*DesiredRegBrank, *CurRegBank);
+    unsigned Cost =
+        RBI->copyCost(*DesiredRegBrank, *CurRegBank,
+                      RegisterBankInfo::getSizeInBits(MO.getReg(), *MRI, *TRI));
     // TODO: use a dedicated constant for ImpossibleCost.
     if (Cost != UINT_MAX)
       return Cost;
diff --git a/lib/Target/AArch64/AArch64RegisterBankInfo.cpp b/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
index a877b79c078..72097a9bbd8 100644
--- a/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
+++ b/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
@@ -64,7 +64,8 @@ AArch64RegisterBankInfo::AArch64RegisterBankInfo(const TargetRegisterInfo &TRI)
 }
 
 unsigned AArch64RegisterBankInfo::copyCost(const RegisterBank &A,
-                                           const RegisterBank &B) const {
+                                           const RegisterBank &B,
+                                           unsigned Size) const {
   // What do we do with different size?
   // copy are same size.
   // Will introduce other hooks for different size:
diff --git a/lib/Target/AArch64/AArch64RegisterBankInfo.h b/lib/Target/AArch64/AArch64RegisterBankInfo.h
index 156f9a0b7d5..69a21ec82cf 100644
--- a/lib/Target/AArch64/AArch64RegisterBankInfo.h
+++ b/lib/Target/AArch64/AArch64RegisterBankInfo.h
@@ -34,9 +34,13 @@ class AArch64RegisterBankInfo : public RegisterBankInfo {
 public:
   AArch64RegisterBankInfo(const TargetRegisterInfo &TRI);
   /// Get the cost of a copy from \p B to \p A, or put differently,
-  /// get the cost of A = COPY B.
-  unsigned copyCost(const RegisterBank &A,
-                    const RegisterBank &B) const override;
+  /// get the cost of A = COPY B. Since register banks may cover
+  /// different size, \p Size specifies what will be the size in bits
+  /// that will be copied around.
+  ///
+  /// \note Since this is a copy, both registers have the same size.
+  unsigned copyCost(const RegisterBank &A, const RegisterBank &B,
+                    unsigned Size) const override;
 
   /// Get a register bank that covers \p RC.
   ///
-- 
2.11.0