include/tcg/tcg-cond.h

   1 /*
   2  * Tiny Code Generator for QEMU
   3  *
   4  * Copyright (c) 2008 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #ifndef TCG_COND_H
  26 #define TCG_COND_H
  27
  28 /*
  29  * Conditions.  Note that these are laid out for easy manipulation by
  30  * the functions below:
  31  *    bit 0 is used for inverting;
  32  *    bit 1 is used for conditions that need swapping (signed/unsigned).
  33  *    bit 2 is used with bit 1 for swapping.
  34  *    bit 3 is used for unsigned conditions.
  35  */
  36 typedef enum {
  37     /* non-signed */
  38     TCG_COND_NEVER  = 0 | 0 | 0 | 0,
  39     TCG_COND_ALWAYS = 0 | 0 | 0 | 1,
  40
  41     /* equality */
  42     TCG_COND_EQ     = 8 | 0 | 0 | 0,
  43     TCG_COND_NE     = 8 | 0 | 0 | 1,
  44
  45     /* "test" i.e. and then compare vs 0 */
  46     TCG_COND_TSTEQ  = 8 | 4 | 0 | 0,
  47     TCG_COND_TSTNE  = 8 | 4 | 0 | 1,
  48
  49     /* signed */
  50     TCG_COND_LT     = 0 | 0 | 2 | 0,
  51     TCG_COND_GE     = 0 | 0 | 2 | 1,
  52     TCG_COND_GT     = 0 | 4 | 2 | 0,
  53     TCG_COND_LE     = 0 | 4 | 2 | 1,
  54
  55     /* unsigned */
  56     TCG_COND_LTU    = 8 | 0 | 2 | 0,
  57     TCG_COND_GEU    = 8 | 0 | 2 | 1,
  58     TCG_COND_GTU    = 8 | 4 | 2 | 0,
  59     TCG_COND_LEU    = 8 | 4 | 2 | 1,
  60 } TCGCond;
  61
  62 /* Invert the sense of the comparison.  */
  63 static inline TCGCond tcg_invert_cond(TCGCond c)
  64 {
  65     return (TCGCond)(c ^ 1);
  66 }
  67
  68 /* Swap the operands in a comparison.  */
  69 static inline TCGCond tcg_swap_cond(TCGCond c)
  70 {
  71     return (TCGCond)(c ^ ((c & 2) << 1));
  72 }
  73
  74 /* Must a comparison be considered signed?  */
  75 static inline bool is_signed_cond(TCGCond c)
  76 {
  77     return (c & (8 | 2)) == 2;
  78 }
  79
  80 /* Must a comparison be considered unsigned?  */
  81 static inline bool is_unsigned_cond(TCGCond c)
  82 {
  83     return (c & (8 | 2)) == (8 | 2);
  84 }
  85
  86 /* Must a comparison be considered a test?  */
  87 static inline bool is_tst_cond(TCGCond c)
  88 {
  89     return (c | 1) == TCG_COND_TSTNE;
  90 }
  91
  92 /* Create an "unsigned" version of a "signed" comparison.  */
  93 static inline TCGCond tcg_unsigned_cond(TCGCond c)
  94 {
  95     return is_signed_cond(c) ? (TCGCond)(c + 8) : c;
  96 }
  97
  98 /* Create a "signed" version of an "unsigned" comparison.  */
  99 static inline TCGCond tcg_signed_cond(TCGCond c)
 100 {
 101     return is_unsigned_cond(c) ? (TCGCond)(c - 8) : c;
 102 }
 103
 104 /* Create the eq/ne version of a tsteq/tstne comparison.  */
 105 static inline TCGCond tcg_tst_eqne_cond(TCGCond c)
 106 {
 107     return is_tst_cond(c) ? (TCGCond)(c - 4) : c;
 108 }
 109
 110 /* Create the lt/ge version of a tstne/tsteq comparison of the sign.  */
 111 static inline TCGCond tcg_tst_ltge_cond(TCGCond c)
 112 {
 113     return is_tst_cond(c) ? (TCGCond)(c ^ 0xf) : c;
 114 }
 115
 116 /*
 117  * Create a "high" version of a double-word comparison.
 118  * This removes equality from a LTE or GTE comparison.
 119  */
 120 static inline TCGCond tcg_high_cond(TCGCond c)
 121 {
 122     switch (c) {
 123     case TCG_COND_GE:
 124     case TCG_COND_LE:
 125     case TCG_COND_GEU:
 126     case TCG_COND_LEU:
 127         return (TCGCond)(c ^ (4 | 1));
 128     default:
 129         return c;
 130     }
 131 }
 132
 133 #endif /* TCG_COND_H */