Add class MipsAnalyzeImmediate which comes up with an instruction sequence to

load an immediate. 

llvm-svn: 148900

1 files changed, 62 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsAnalyzeImmediate.h b/llvm/lib/Target/Mips/MipsAnalyzeImmediate.h
new file mode 100644
index 00000000000..fe181d8d342
--- /dev/null
+++ b/llvm/lib/Target/Mips/MipsAnalyzeImmediate.h
@@ -0,0 +1,62 @@
+//===-- MipsAnalyzeImmediate.h - Analyze immediates -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#ifndef MIPS_ANALYZE_IMMEDIATE_H
+#define MIPS_ANALYZE_IMMEDIATE_H
+
+#include "llvm/ADT/SmallVector.h"
+
+namespace llvm {
+
+  class MipsAnalyzeImmediate {
+  public:
+    struct Inst {
+      unsigned Opc, ImmOpnd;
+      Inst(unsigned Opc, unsigned ImmOpnd);
+    };
+    typedef SmallVector<Inst, 7 > InstSeq;
+
+    /// Analyze - Get an instrucion sequence to load immediate Imm. The last
+    /// instruction in the sequence must be an ADDiu if LastInstrIsADDiu is
+    /// true;
+    const InstSeq &Analyze(int64_t Imm, unsigned Size, bool LastInstrIsADDiu);
+  private:
+    typedef SmallVector<InstSeq, 5> InstSeqLs;
+
+    /// AddInstr - Add I to all instruction sequences in SeqLs.
+    void AddInstr(InstSeqLs &SeqLs, const Inst &I);
+
+    /// GetInstSeqLsADDiu - Get instrucion sequences which end with an ADDiu to
+    /// load immediate Imm
+    void GetInstSeqLsADDiu(int64_t Imm, unsigned RemSize, InstSeqLs &SeqLs);
+
+    /// GetInstSeqLsORi - Get instrucion sequences which end with an ORi to
+    /// load immediate Imm
+    void GetInstSeqLsORi(int64_t Imm, unsigned RemSize, InstSeqLs &SeqLs);
+
+    /// GetInstSeqLsSLL - Get instrucion sequences which end with a SLL to
+    /// load immediate Imm
+    void GetInstSeqLsSLL(int64_t Imm, unsigned RemSize, InstSeqLs &SeqLs);
+
+    /// GetInstSeqLs - Get instrucion sequences to load immediate Imm.
+    void GetInstSeqLs(int64_t Imm, unsigned RemSize, InstSeqLs &SeqLs);
+
+    /// ReplaceADDiuSLLWithLUi - Replace an ADDiu & SLL pair with a LUi.
+    void ReplaceADDiuSLLWithLUi(InstSeq &Seq);
+
+    /// GetShortestSeq - Find the shortest instruction sequence in SeqLs and
+    /// return it in Insts. 
+    void GetShortestSeq(InstSeqLs &SeqLs, InstSeq &Insts);
+
+    unsigned Size;
+    unsigned ADDiu, ORi, SLL, LUi;
+    InstSeq Insts;
+  };
+}
+
+#endif