dfg/DFGNodeFlags.h

   1 /*
   2  * Copyright (C) 2012, 2013 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef DFGNodeFlags_h
  27 #define DFGNodeFlags_h
  28
  29 #include <wtf/Platform.h>
  30
  31 #if ENABLE(DFG_JIT)
  32
  33 #include <wtf/PrintStream.h>
  34 #include <wtf/StdLibExtras.h>
  35
  36 namespace JSC { namespace DFG {
  37
  38 // Entries in the NodeType enum (below) are composed of an id, a result type (possibly none)
  39 // and some additional informative flags (must generate, is constant, etc).
  40 #define NodeResultMask              0x7
  41 #define NodeResultJS                0x1
  42 #define NodeResultNumber            0x2
  43 #define NodeResultInt32             0x3
  44 #define NodeResultBoolean           0x4
  45 #define NodeResultStorage           0x5
  46
  47 #define NodeMustGenerate           0x08 // set on nodes that have side effects, and may not trivially be removed by DCE.
  48 #define NodeHasVarArgs             0x10
  49 #define NodeClobbersWorld          0x20
  50 #define NodeMightClobber           0x40
  51
  52 #define NodeBehaviorMask          0x180
  53 #define NodeMayOverflow           0x080
  54 #define NodeMayNegZero            0x100
  55
  56 #define NodeBackPropMask         0x1E00
  57 #define NodeUseBottom            0x0000
  58 #define NodeUsedAsNumber         0x0200 // The result of this computation may be used in a context that observes fractional, or bigger-than-int32, results.
  59 #define NodeNeedsNegZero         0x0400 // The result of this computation may be used in a context that observes -0.
  60 #define NodeUsedAsOther          0x0800 // The result of this computation may be used in a context that distinguishes between NaN and other things (like undefined).
  61 #define NodeUsedAsValue          (NodeUsedAsNumber | NodeNeedsNegZero | NodeUsedAsOther)
  62 #define NodeUsedAsInt            0x1000 // The result of this computation is known to be used in a context that prefers, but does not require, integer values.
  63
  64 #define NodeArithFlagsMask       (NodeBehaviorMask | NodeBackPropMask)
  65
  66 #define NodeDoesNotExit          0x2000 // This flag is negated to make it natural for the default to be that a node does exit.
  67
  68 #define NodeRelevantToOSR        0x4000
  69
  70 #define NodeExitsForward         0x8000
  71
  72 typedef uint32_t NodeFlags;
  73
  74 static inline bool nodeUsedAsNumber(NodeFlags flags)
  75 {
  76     return !!(flags & NodeUsedAsNumber);
  77 }
  78
  79 static inline bool nodeCanTruncateInteger(NodeFlags flags)
  80 {
  81     return !nodeUsedAsNumber(flags);
  82 }
  83
  84 static inline bool nodeCanIgnoreNegativeZero(NodeFlags flags)
  85 {
  86     return !(flags & NodeNeedsNegZero);
  87 }
  88
  89 static inline bool nodeMayOverflow(NodeFlags flags)
  90 {
  91     return !!(flags & NodeMayOverflow);
  92 }
  93
  94 static inline bool nodeCanSpeculateInteger(NodeFlags flags)
  95 {
  96     if (flags & NodeMayOverflow)
  97         return !nodeUsedAsNumber(flags);
  98
  99     if (flags & NodeMayNegZero)
 100         return nodeCanIgnoreNegativeZero(flags);
 101
 102     return true;
 103 }
 104
 105 void dumpNodeFlags(PrintStream&, NodeFlags);
 106 MAKE_PRINT_ADAPTOR(NodeFlagsDump, NodeFlags, dumpNodeFlags);
 107
 108 } } // namespace JSC::DFG
 109
 110 #endif // ENABLE(DFG_JIT)
 111
 112 #endif // DFGNodeFlags_h
 113