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      1 //===-- PPCPredicates.h - PPC Branch Predicate Information ------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file describes the PowerPC branch predicates.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_LIB_TARGET_POWERPC_MCTARGETDESC_PPCPREDICATES_H
     15 #define LLVM_LIB_TARGET_POWERPC_MCTARGETDESC_PPCPREDICATES_H
     16 
     17 // GCC #defines PPC on Linux but we use it as our namespace name
     18 #undef PPC
     19 
     20 // Generated files will use "namespace PPC". To avoid symbol clash,
     21 // undefine PPC here. PPC may be predefined on some hosts.
     22 #undef PPC
     23 
     24 namespace llvm {
     25 namespace PPC {
     26   /// Predicate - These are "(BI << 5) | BO"  for various predicates.
     27   enum Predicate {
     28     PRED_LT       = (0 << 5) | 12,
     29     PRED_LE       = (1 << 5) |  4,
     30     PRED_EQ       = (2 << 5) | 12,
     31     PRED_GE       = (0 << 5) |  4,
     32     PRED_GT       = (1 << 5) | 12,
     33     PRED_NE       = (2 << 5) |  4,
     34     PRED_UN       = (3 << 5) | 12,
     35     PRED_NU       = (3 << 5) |  4,
     36     PRED_LT_MINUS = (0 << 5) | 14,
     37     PRED_LE_MINUS = (1 << 5) |  6,
     38     PRED_EQ_MINUS = (2 << 5) | 14,
     39     PRED_GE_MINUS = (0 << 5) |  6,
     40     PRED_GT_MINUS = (1 << 5) | 14,
     41     PRED_NE_MINUS = (2 << 5) |  6,
     42     PRED_UN_MINUS = (3 << 5) | 14,
     43     PRED_NU_MINUS = (3 << 5) |  6,
     44     PRED_LT_PLUS  = (0 << 5) | 15,
     45     PRED_LE_PLUS  = (1 << 5) |  7,
     46     PRED_EQ_PLUS  = (2 << 5) | 15,
     47     PRED_GE_PLUS  = (0 << 5) |  7,
     48     PRED_GT_PLUS  = (1 << 5) | 15,
     49     PRED_NE_PLUS  = (2 << 5) |  7,
     50     PRED_UN_PLUS  = (3 << 5) | 15,
     51     PRED_NU_PLUS  = (3 << 5) |  7,
     52 
     53     // When dealing with individual condition-register bits, we have simple set
     54     // and unset predicates.
     55     PRED_BIT_SET =   1024,
     56     PRED_BIT_UNSET = 1025
     57   };
     58 
     59   // Bit for branch taken (plus) or not-taken (minus) hint
     60   enum BranchHintBit {
     61     BR_NO_HINT       = 0x0,
     62     BR_NONTAKEN_HINT = 0x2,
     63     BR_TAKEN_HINT    = 0x3,
     64     BR_HINT_MASK     = 0X3
     65   };
     66 
     67   /// Invert the specified predicate.  != -> ==, < -> >=.
     68   Predicate InvertPredicate(Predicate Opcode);
     69 
     70   /// Assume the condition register is set by MI(a,b), return the predicate if
     71   /// we modify the instructions such that condition register is set by MI(b,a).
     72   Predicate getSwappedPredicate(Predicate Opcode);
     73 }
     74 }
     75 
     76 #endif
     77