[SystemZ] Add back end

This adds the actual lib/Target/SystemZ target files necessary to
implement the SystemZ target.  Note that at this point, the target
cannot yet be built since the configure bits are missing.  Those
will be provided shortly by a follow-on patch.

This version of the patch incorporates feedback from reviews by
Chris Lattner and Anton Korobeynikov.  Thanks to all reviewers!

Patch by Richard Sandiford.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181203 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 77 insertions, 0 deletions

diff --git a/lib/Target/SystemZ/SystemZ.h b/lib/Target/SystemZ/SystemZ.h
new file mode 100644
index 0000000000..b811cbe9f0
--- /dev/null
+++ b/lib/Target/SystemZ/SystemZ.h
@@ -0,0 +1,77 @@
+//==- SystemZ.h - Top-Level Interface for SystemZ representation -*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the entry points for global functions defined in
+// the LLVM SystemZ backend.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SYSTEMZ_H
+#define SYSTEMZ_H
+
+#include "MCTargetDesc/SystemZMCTargetDesc.h"
+#include "llvm/Support/CodeGen.h"
+
+namespace llvm {
+  class SystemZTargetMachine;
+  class FunctionPass;
+
+  namespace SystemZ {
+    // Condition-code mask values.
+    const unsigned CCMASK_0 = 1 << 3;
+    const unsigned CCMASK_1 = 1 << 2;
+    const unsigned CCMASK_2 = 1 << 1;
+    const unsigned CCMASK_3 = 1 << 0;
+    const unsigned CCMASK_ANY = CCMASK_0 | CCMASK_1 | CCMASK_2 | CCMASK_3;
+
+    // Condition-code mask assignments for floating-point comparisons.
+    const unsigned CCMASK_CMP_EQ = CCMASK_0;
+    const unsigned CCMASK_CMP_LT = CCMASK_1;
+    const unsigned CCMASK_CMP_GT = CCMASK_2;
+    const unsigned CCMASK_CMP_UO = CCMASK_3;
+    const unsigned CCMASK_CMP_NE = CCMASK_CMP_LT | CCMASK_CMP_GT;
+    const unsigned CCMASK_CMP_LE = CCMASK_CMP_EQ | CCMASK_CMP_LT;
+    const unsigned CCMASK_CMP_GE = CCMASK_CMP_EQ | CCMASK_CMP_GT;
+    const unsigned CCMASK_CMP_O  = CCMASK_ANY ^ CCMASK_CMP_UO;
+
+    // Return true if Val fits an LLILL operand.
+    static inline bool isImmLL(uint64_t Val) {
+      return (Val & ~0x000000000000ffffULL) == 0;
+    }
+
+    // Return true if Val fits an LLILH operand.
+    static inline bool isImmLH(uint64_t Val) {
+      return (Val & ~0x00000000ffff0000ULL) == 0;
+    }
+
+    // Return true if Val fits an LLIHL operand.
+    static inline bool isImmHL(uint64_t Val) {
+      return (Val & ~0x00000ffff00000000ULL) == 0;
+    }
+
+    // Return true if Val fits an LLIHH operand.
+    static inline bool isImmHH(uint64_t Val) {
+      return (Val & ~0xffff000000000000ULL) == 0;
+    }
+
+    // Return true if Val fits an LLILF operand.
+    static inline bool isImmLF(uint64_t Val) {
+      return (Val & ~0x00000000ffffffffULL) == 0;
+    }
+
+    // Return true if Val fits an LLIHF operand.
+    static inline bool isImmHF(uint64_t Val) {
+      return (Val & ~0xffffffff00000000ULL) == 0;
+    }
+  }
+
+  FunctionPass *createSystemZISelDag(SystemZTargetMachine &TM,
+                                     CodeGenOpt::Level OptLevel);
+} // end namespace llvm;
+#endif