llvm-project/llvm/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h

93 lines
3.0 KiB
C++

//===-- PPCPredicates.h - PPC Branch Predicate Information ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file describes the PowerPC branch predicates.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_POWERPC_MCTARGETDESC_PPCPREDICATES_H
#define LLVM_LIB_TARGET_POWERPC_MCTARGETDESC_PPCPREDICATES_H
// GCC #defines PPC on Linux but we use it as our namespace name
#undef PPC
// Generated files will use "namespace PPC". To avoid symbol clash,
// undefine PPC here. PPC may be predefined on some hosts.
#undef PPC
namespace llvm {
namespace PPC {
/// Predicate - These are "(BI << 5) | BO" for various predicates.
enum Predicate {
PRED_LT = (0 << 5) | 12,
PRED_LE = (1 << 5) | 4,
PRED_EQ = (2 << 5) | 12,
PRED_GE = (0 << 5) | 4,
PRED_GT = (1 << 5) | 12,
PRED_NE = (2 << 5) | 4,
PRED_UN = (3 << 5) | 12,
PRED_NU = (3 << 5) | 4,
PRED_LT_MINUS = (0 << 5) | 14,
PRED_LE_MINUS = (1 << 5) | 6,
PRED_EQ_MINUS = (2 << 5) | 14,
PRED_GE_MINUS = (0 << 5) | 6,
PRED_GT_MINUS = (1 << 5) | 14,
PRED_NE_MINUS = (2 << 5) | 6,
PRED_UN_MINUS = (3 << 5) | 14,
PRED_NU_MINUS = (3 << 5) | 6,
PRED_LT_PLUS = (0 << 5) | 15,
PRED_LE_PLUS = (1 << 5) | 7,
PRED_EQ_PLUS = (2 << 5) | 15,
PRED_GE_PLUS = (0 << 5) | 7,
PRED_GT_PLUS = (1 << 5) | 15,
PRED_NE_PLUS = (2 << 5) | 7,
PRED_UN_PLUS = (3 << 5) | 15,
PRED_NU_PLUS = (3 << 5) | 7,
// When dealing with individual condition-register bits, we have simple set
// and unset predicates.
PRED_BIT_SET = 1024,
PRED_BIT_UNSET = 1025
};
// Bit for branch taken (plus) or not-taken (minus) hint
enum BranchHintBit {
BR_NO_HINT = 0x0,
BR_NONTAKEN_HINT = 0x2,
BR_TAKEN_HINT = 0x3,
BR_HINT_MASK = 0X3
};
/// Invert the specified predicate. != -> ==, < -> >=.
Predicate InvertPredicate(Predicate Opcode);
/// Assume the condition register is set by MI(a,b), return the predicate if
/// we modify the instructions such that condition register is set by MI(b,a).
Predicate getSwappedPredicate(Predicate Opcode);
/// Return the condition without hint bits.
inline unsigned getPredicateCondition(Predicate Opcode) {
return (unsigned)(Opcode & ~BR_HINT_MASK);
}
/// Return the hint bits of the predicate.
inline unsigned getPredicateHint(Predicate Opcode) {
return (unsigned)(Opcode & BR_HINT_MASK);
}
/// Return predicate consisting of specified condition and hint bits.
inline Predicate getPredicate(unsigned Condition, unsigned Hint) {
return (Predicate)((Condition & ~BR_HINT_MASK) |
(Hint & BR_HINT_MASK));
}
}
}
#endif