diff options
Diffstat (limited to 'other-licenses/7zstub/src/7zip/Compress/Branch/BranchX86.c')
-rw-r--r-- | other-licenses/7zstub/src/7zip/Compress/Branch/BranchX86.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/other-licenses/7zstub/src/7zip/Compress/Branch/BranchX86.c b/other-licenses/7zstub/src/7zip/Compress/Branch/BranchX86.c new file mode 100644 index 000000000..2d2c03d2d --- /dev/null +++ b/other-licenses/7zstub/src/7zip/Compress/Branch/BranchX86.c @@ -0,0 +1,101 @@ +/* BranchX86.c */
+
+#include "BranchX86.h"
+
+/*
+static int inline Test86MSByte(Byte b)
+{
+ return (b == 0 || b == 0xFF);
+}
+*/
+#define Test86MSByte(b) ((b) == 0 || (b) == 0xFF)
+
+const int kMaskToAllowedStatus[8] = {1, 1, 1, 0, 1, 0, 0, 0};
+const Byte kMaskToBitNumber[8] = {0, 1, 2, 2, 3, 3, 3, 3};
+
+/*
+void x86_Convert_Init(UInt32 *prevMask, UInt32 *prevPos)
+{
+ *prevMask = 0;
+ *prevPos = (UInt32)(-5);
+}
+*/
+
+UInt32 x86_Convert(Byte *buffer, UInt32 endPos, UInt32 nowPos,
+ UInt32 *prevMask, UInt32 *prevPos, int encoding)
+{
+ UInt32 bufferPos = 0;
+ UInt32 limit;
+
+ if (endPos < 5)
+ return 0;
+
+ if (nowPos - *prevPos > 5)
+ *prevPos = nowPos - 5;
+
+ limit = endPos - 5;
+ while(bufferPos <= limit)
+ {
+ Byte b = buffer[bufferPos];
+ UInt32 offset;
+ if (b != 0xE8 && b != 0xE9)
+ {
+ bufferPos++;
+ continue;
+ }
+ offset = (nowPos + bufferPos - *prevPos);
+ *prevPos = (nowPos + bufferPos);
+ if (offset > 5)
+ *prevMask = 0;
+ else
+ {
+ UInt32 i;
+ for (i = 0; i < offset; i++)
+ {
+ *prevMask &= 0x77;
+ *prevMask <<= 1;
+ }
+ }
+ b = buffer[bufferPos + 4];
+ if (Test86MSByte(b) && kMaskToAllowedStatus[(*prevMask >> 1) & 0x7] &&
+ (*prevMask >> 1) < 0x10)
+ {
+ UInt32 src =
+ ((UInt32)(b) << 24) |
+ ((UInt32)(buffer[bufferPos + 3]) << 16) |
+ ((UInt32)(buffer[bufferPos + 2]) << 8) |
+ (buffer[bufferPos + 1]);
+
+ UInt32 dest;
+ while(1)
+ {
+ UInt32 index;
+ if (encoding)
+ dest = (nowPos + bufferPos + 5) + src;
+ else
+ dest = src - (nowPos + bufferPos + 5);
+ if (*prevMask == 0)
+ break;
+ index = kMaskToBitNumber[*prevMask >> 1];
+ b = (Byte)(dest >> (24 - index * 8));
+ if (!Test86MSByte(b))
+ break;
+ src = dest ^ ((1 << (32 - index * 8)) - 1);
+ }
+ buffer[bufferPos + 4] = (Byte)(~(((dest >> 24) & 1) - 1));
+ buffer[bufferPos + 3] = (Byte)(dest >> 16);
+ buffer[bufferPos + 2] = (Byte)(dest >> 8);
+ buffer[bufferPos + 1] = (Byte)dest;
+ bufferPos += 5;
+ *prevMask = 0;
+ }
+ else
+ {
+ bufferPos++;
+ *prevMask |= 1;
+ if (Test86MSByte(b))
+ *prevMask |= 0x10;
+ }
+ }
+ return bufferPos;
+}
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