LLVM  10.0.0svn
PPCPredicates.h
Go to the documentation of this file.
1 //===-- PPCPredicates.h - PPC Branch Predicate Information ------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file describes the PowerPC branch predicates.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_POWERPC_MCTARGETDESC_PPCPREDICATES_H
14 #define LLVM_LIB_TARGET_POWERPC_MCTARGETDESC_PPCPREDICATES_H
15 
16 // GCC #defines PPC on Linux but we use it as our namespace name
17 #undef PPC
18 
19 // Generated files will use "namespace PPC". To avoid symbol clash,
20 // undefine PPC here. PPC may be predefined on some hosts.
21 #undef PPC
22 
23 namespace llvm {
24 namespace PPC {
25  /// Predicate - These are "(BI << 5) | BO" for various predicates.
26  enum Predicate {
27  PRED_LT = (0 << 5) | 12,
28  PRED_LE = (1 << 5) | 4,
29  PRED_EQ = (2 << 5) | 12,
30  PRED_GE = (0 << 5) | 4,
31  PRED_GT = (1 << 5) | 12,
32  PRED_NE = (2 << 5) | 4,
33  PRED_UN = (3 << 5) | 12,
34  PRED_NU = (3 << 5) | 4,
35  PRED_LT_MINUS = (0 << 5) | 14,
36  PRED_LE_MINUS = (1 << 5) | 6,
37  PRED_EQ_MINUS = (2 << 5) | 14,
38  PRED_GE_MINUS = (0 << 5) | 6,
39  PRED_GT_MINUS = (1 << 5) | 14,
40  PRED_NE_MINUS = (2 << 5) | 6,
41  PRED_UN_MINUS = (3 << 5) | 14,
42  PRED_NU_MINUS = (3 << 5) | 6,
43  PRED_LT_PLUS = (0 << 5) | 15,
44  PRED_LE_PLUS = (1 << 5) | 7,
45  PRED_EQ_PLUS = (2 << 5) | 15,
46  PRED_GE_PLUS = (0 << 5) | 7,
47  PRED_GT_PLUS = (1 << 5) | 15,
48  PRED_NE_PLUS = (2 << 5) | 7,
49  PRED_UN_PLUS = (3 << 5) | 15,
50  PRED_NU_PLUS = (3 << 5) | 7,
51 
52  // SPE scalar compare instructions always set the GT bit.
54 
55  // When dealing with individual condition-register bits, we have simple set
56  // and unset predicates.
57  PRED_BIT_SET = 1024,
59  };
60 
61  // Bit for branch taken (plus) or not-taken (minus) hint
63  BR_NO_HINT = 0x0,
67  };
68 
69  /// Invert the specified predicate. != -> ==, < -> >=.
71 
72  /// Assume the condition register is set by MI(a,b), return the predicate if
73  /// we modify the instructions such that condition register is set by MI(b,a).
75 
76  /// Return the condition without hint bits.
77  inline unsigned getPredicateCondition(Predicate Opcode) {
78  return (unsigned)(Opcode & ~BR_HINT_MASK);
79  }
80 
81  /// Return the hint bits of the predicate.
82  inline unsigned getPredicateHint(Predicate Opcode) {
83  return (unsigned)(Opcode & BR_HINT_MASK);
84  }
85 
86  /// Return predicate consisting of specified condition and hint bits.
87  inline Predicate getPredicate(unsigned Condition, unsigned Hint) {
88  return (Predicate)((Condition & ~BR_HINT_MASK) |
89  (Hint & BR_HINT_MASK));
90  }
91 }
92 }
93 
94 #endif
This class represents lattice values for constants.
Definition: AllocatorList.h:23
unsigned getPredicateHint(Predicate Opcode)
Return the hint bits of the predicate.
Definition: PPCPredicates.h:82
Predicate getPredicate(unsigned Condition, unsigned Hint)
Return predicate consisting of specified condition and hint bits.
Definition: PPCPredicates.h:87
Predicate InvertPredicate(Predicate Opcode)
Invert the specified predicate. != -> ==, < -> >=.
unsigned getPredicateCondition(Predicate Opcode)
Return the condition without hint bits.
Definition: PPCPredicates.h:77
Predicate getSwappedPredicate(Predicate Opcode)
Assume the condition register is set by MI(a,b), return the predicate if we modify the instructions s...