Convert ZydisDecoder field decoder_mode to a bitmap.

Make decoder_mode a bitmap instead of an array of booleans for space
efficiency.

Author: jpidancet

include/Zydis/Decoder.h

@@ -176,9 +176,9 @@ typedef struct ZydisDecoder_
      */
     ZydisStackWidth stack_width;
     /**
-     * The decoder mode array.
+     * The decoder mode bitmap.
      */
-    ZyanBool decoder_mode[ZYDIS_DECODER_MODE_MAX_VALUE + 1];
+    ZyanU32 decoder_mode;
 } ZydisDecoder;
 
 /* ---------------------------------------------------------------------------------------------- */

src/Decoder.c

@@ -2103,7 +2103,7 @@ static void ZydisSetAttributes(ZydisDecoderState* state, ZydisDecodedInstruction
                     break;
                 }
             }
-            if (state->decoder->decoder_mode[ZYDIS_DECODER_MODE_MPX] &&
+            if ((state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_MPX)) &&
                 instruction->attributes & ZYDIS_ATTRIB_ACCEPTS_BND)
             {
                 instruction->attributes |= ZYDIS_ATTRIB_HAS_BND;
@@ -2167,7 +2167,7 @@ static void ZydisSetAttributes(ZydisDecoderState* state, ZydisDecodedInstruction
         if (def->accepts_NOTRACK)
         {
             instruction->attributes |= ZYDIS_ATTRIB_ACCEPTS_NOTRACK;
-            if (state->decoder->decoder_mode[ZYDIS_DECODER_MODE_CET] &&
+            if ((state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_CET)) &&
                 (state->prefixes.offset_notrack >= 0))
             {
                 instruction->attributes |= ZYDIS_ATTRIB_HAS_NOTRACK;
@@ -4777,31 +4777,31 @@ static ZyanStatus ZydisDecodeInstruction(ZydisDecoderState* state,
             break;
 #endif
         case ZYDIS_NODETYPE_FILTER_MODE_AMD:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_AMD_BRANCHES] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_AMD_BRANCHES));
             break;
         case ZYDIS_NODETYPE_FILTER_MODE_KNC:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_KNC] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_KNC));
             break;
         case ZYDIS_NODETYPE_FILTER_MODE_MPX:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_MPX] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_MPX));
             break;
         case ZYDIS_NODETYPE_FILTER_MODE_CET:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_CET] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_CET));
             break;
         case ZYDIS_NODETYPE_FILTER_MODE_LZCNT:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_LZCNT] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_LZCNT));
             break;
         case ZYDIS_NODETYPE_FILTER_MODE_TZCNT:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_TZCNT] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_TZCNT));
             break;
         case ZYDIS_NODETYPE_FILTER_MODE_WBNOINVD:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_WBNOINVD] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_WBNOINVD));
             break;
         case ZYDIS_NODETYPE_FILTER_MODE_CLDEMOTE:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_CLDEMOTE] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_CLDEMOTE));
             break;
         case ZYDIS_NODETYPE_FILTER_MODE_IPREFETCH:
-            index = state->decoder->decoder_mode[ZYDIS_DECODER_MODE_IPREFETCH] ? 1 : 0;
+            index = !!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_IPREFETCH));
             break;
         default:
             if (node_type & ZYDIS_NODETYPE_DEFINITION_MASK)
@@ -4854,7 +4854,7 @@ static ZyanStatus ZydisDecodeInstruction(ZydisDecoderState* state,
                          (instruction->meta.category == ZYDIS_CATEGORY_RET)));
                 instruction->meta.exception_class = definition->exception_class;
 
-                if (!state->decoder->decoder_mode[ZYDIS_DECODER_MODE_MINIMAL])
+                if (!(state->decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_MINIMAL)))
                 {
                     ZydisSetAttributes(state, instruction, definition);
                     switch (instruction->encoding)
@@ -4899,23 +4899,15 @@ static ZyanStatus ZydisDecodeInstruction(ZydisDecoderState* state,
 ZyanStatus ZydisDecoderInit(ZydisDecoder* decoder, ZydisMachineMode machine_mode,
     ZydisStackWidth stack_width)
 {
-    static const ZyanBool decoder_modes[ZYDIS_DECODER_MODE_MAX_VALUE + 1] =
-    {
+    static const ZyanU32 decoder_modes =
 #ifdef ZYDIS_MINIMAL_MODE
-        ZYAN_TRUE , // ZYDIS_DECODER_MODE_MINIMAL
-#else
-        ZYAN_FALSE, // ZYDIS_DECODER_MODE_MINIMAL
+        (1 << ZYDIS_DECODER_MODE_MINIMAL) |
 #endif
-        ZYAN_FALSE, // ZYDIS_DECODER_MODE_AMD_BRANCHES
-        ZYAN_FALSE, // ZYDIS_DECODER_MODE_KNC
-        ZYAN_TRUE , // ZYDIS_DECODER_MODE_MPX
-        ZYAN_TRUE , // ZYDIS_DECODER_MODE_CET
-        ZYAN_TRUE , // ZYDIS_DECODER_MODE_LZCNT
-        ZYAN_TRUE , // ZYDIS_DECODER_MODE_TZCNT
-        ZYAN_FALSE, // ZYDIS_DECODER_MODE_WBNOINVD
-        ZYAN_TRUE,  // ZYDIS_DECODER_MODE_CLDEMOTE
-        ZYAN_FALSE  // ZYDIS_DECODER_MODE_IPREFETCH
-    };
+        (1 << ZYDIS_DECODER_MODE_MPX) |
+        (1 << ZYDIS_DECODER_MODE_CET) |
+        (1 << ZYDIS_DECODER_MODE_LZCNT) |
+        (1 << ZYDIS_DECODER_MODE_TZCNT) |
+        (1 << ZYDIS_DECODER_MODE_CLDEMOTE);
 
     if (!decoder)
     {
@@ -4945,7 +4937,7 @@ ZyanStatus ZydisDecoderInit(ZydisDecoder* decoder, ZydisMachineMode machine_mode
 
     decoder->machine_mode = machine_mode;
     decoder->stack_width = stack_width;
-    ZYAN_MEMCPY(&decoder->decoder_mode, &decoder_modes, sizeof(decoder_modes));
+    decoder->decoder_mode = decoder_modes;
 
     return ZYAN_STATUS_SUCCESS;
 }
@@ -4964,7 +4956,14 @@ ZyanStatus ZydisDecoderEnableMode(ZydisDecoder* decoder, ZydisDecoderMode mode,
     }
 #endif
 
-    decoder->decoder_mode[mode] = enabled;
+    if (enabled)
+    {
+        decoder->decoder_mode |= (1 << mode);
+    }
+    else
+    {
+        decoder->decoder_mode &= ~(1 << mode);
+    }
 
     return ZYAN_STATUS_SUCCESS;
 }
@@ -4981,7 +4980,7 @@ ZyanStatus ZydisDecoderDecodeFull(const ZydisDecoder* decoder,
     {
         return ZYDIS_STATUS_NO_MORE_DATA;
     }
-    if (decoder->decoder_mode[ZYDIS_DECODER_MODE_MINIMAL])
+    if (decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_MINIMAL))
     {
         return ZYAN_STATUS_MISSING_DEPENDENCY; // TODO: Introduce better status code
     }
@@ -5059,7 +5058,7 @@ ZyanStatus ZydisDecoderDecodeOperands(const ZydisDecoder* decoder,
         return ZYAN_STATUS_INVALID_ARGUMENT;
     }
 
-    if (decoder->decoder_mode[ZYDIS_DECODER_MODE_MINIMAL])
+    if (decoder->decoder_mode & (1 << ZYDIS_DECODER_MODE_MINIMAL))
     {
         return ZYAN_STATUS_MISSING_DEPENDENCY; // TODO: Introduce better status code
     }