[AArch64] Teach RegisterBankInfo about the mapping of register classes

on register banks.

llvm-svn: 265626

diff --git a/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp b/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
index 6adfc2a..5f70c4b 100644 (file)
--- a/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp
@@ -63,3 +63,38 @@ unsigned AArch64RegisterBankInfo::copyCost(const RegisterBank &A,
   // * build_sequence cost.
   return 0;
 }
+
+const RegisterBank &AArch64RegisterBankInfo::getRegBankFromRegClass(
+    const TargetRegisterClass &RC) const {
+  switch (RC.getID()) {
+  case AArch64::FPR8RegClassID:
+  case AArch64::FPR16RegClassID:
+  case AArch64::FPR32RegClassID:
+  case AArch64::FPR64RegClassID:
+  case AArch64::FPR128RegClassID:
+  case AArch64::FPR128_loRegClassID:
+  case AArch64::DDRegClassID:
+  case AArch64::DDDRegClassID:
+  case AArch64::DDDDRegClassID:
+  case AArch64::QQRegClassID:
+  case AArch64::QQQRegClassID:
+  case AArch64::QQQQRegClassID:
+    return getRegBank(AArch64::FPRRegBankID);
+  case AArch64::GPR32commonRegClassID:
+  case AArch64::GPR32RegClassID:
+  case AArch64::GPR32spRegClassID:
+  case AArch64::GPR32sponlyRegClassID:
+  case AArch64::GPR32allRegClassID:
+  case AArch64::GPR64commonRegClassID:
+  case AArch64::GPR64RegClassID:
+  case AArch64::GPR64spRegClassID:
+  case AArch64::GPR64sponlyRegClassID:
+  case AArch64::GPR64allRegClassID:
+  case AArch64::tcGPR64RegClassID:
+  case AArch64::WSeqPairsClassRegClassID:
+  case AArch64::XSeqPairsClassRegClassID:
+    return getRegBank(AArch64::FPRRegBankID);
+  default:
+    llvm_unreachable("Register class not supported");
+  }
+}

diff --git a/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.h b/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.h
index c6019b5..c58d452 100644 (file)
--- a/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.h
@@ -36,6 +36,21 @@ public:
   /// get the cost of A = COPY B.
   unsigned copyCost(const RegisterBank &A,
                     const RegisterBank &B) const override;
+
+  /// Get a register bank that covers \p RC.
+  ///
+  /// \pre \p RC is a user-defined register class (as opposed as one
+  /// generated by TableGen).
+  ///
+  /// \note The mapping RC -> RegBank could be built while adding the
+  /// coverage for the register banks. However, we do not do it, because,
+  /// at least for now, we only need this information for register classes
+  /// that are used in the description of instruction. In other words,
+  /// there are just a handful of them and we do not want to waste space.
+  ///
+  /// \todo This should be TableGen'ed.
+  const RegisterBank &
+  getRegBankFromRegClass(const TargetRegisterClass &RC) const override;
 };
 } // End llvm namespace.
 #endif