diff options
Diffstat (limited to 'other-licenses/7zstub/src/C/Bcj2.c')
| -rw-r--r-- | other-licenses/7zstub/src/C/Bcj2.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/other-licenses/7zstub/src/C/Bcj2.c b/other-licenses/7zstub/src/C/Bcj2.c new file mode 100644 index 000000000..da93985cf --- /dev/null +++ b/other-licenses/7zstub/src/C/Bcj2.c @@ -0,0 +1,257 @@ +/* Bcj2.c -- BCJ2 Decoder (Converter for x86 code)
+2018-04-28 : Igor Pavlov : Public domain */
+
+#include "Precomp.h"
+
+#include "Bcj2.h"
+#include "CpuArch.h"
+
+#define CProb UInt16
+
+#define kTopValue ((UInt32)1 << 24)
+#define kNumModelBits 11
+#define kBitModelTotal (1 << kNumModelBits)
+#define kNumMoveBits 5
+
+#define _IF_BIT_0 ttt = *prob; bound = (p->range >> kNumModelBits) * ttt; if (p->code < bound)
+#define _UPDATE_0 p->range = bound; *prob = (CProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
+#define _UPDATE_1 p->range -= bound; p->code -= bound; *prob = (CProb)(ttt - (ttt >> kNumMoveBits));
+
+void Bcj2Dec_Init(CBcj2Dec *p)
+{
+ unsigned i;
+
+ p->state = BCJ2_DEC_STATE_OK;
+ p->ip = 0;
+ p->temp[3] = 0;
+ p->range = 0;
+ p->code = 0;
+ for (i = 0; i < sizeof(p->probs) / sizeof(p->probs[0]); i++)
+ p->probs[i] = kBitModelTotal >> 1;
+}
+
+SRes Bcj2Dec_Decode(CBcj2Dec *p)
+{
+ if (p->range <= 5)
+ {
+ p->state = BCJ2_DEC_STATE_OK;
+ for (; p->range != 5; p->range++)
+ {
+ if (p->range == 1 && p->code != 0)
+ return SZ_ERROR_DATA;
+
+ if (p->bufs[BCJ2_STREAM_RC] == p->lims[BCJ2_STREAM_RC])
+ {
+ p->state = BCJ2_STREAM_RC;
+ return SZ_OK;
+ }
+
+ p->code = (p->code << 8) | *(p->bufs[BCJ2_STREAM_RC])++;
+ }
+
+ if (p->code == 0xFFFFFFFF)
+ return SZ_ERROR_DATA;
+
+ p->range = 0xFFFFFFFF;
+ }
+ else if (p->state >= BCJ2_DEC_STATE_ORIG_0)
+ {
+ while (p->state <= BCJ2_DEC_STATE_ORIG_3)
+ {
+ Byte *dest = p->dest;
+ if (dest == p->destLim)
+ return SZ_OK;
+ *dest = p->temp[(size_t)p->state - BCJ2_DEC_STATE_ORIG_0];
+ p->state++;
+ p->dest = dest + 1;
+ }
+ }
+
+ /*
+ if (BCJ2_IS_32BIT_STREAM(p->state))
+ {
+ const Byte *cur = p->bufs[p->state];
+ if (cur == p->lims[p->state])
+ return SZ_OK;
+ p->bufs[p->state] = cur + 4;
+
+ {
+ UInt32 val;
+ Byte *dest;
+ SizeT rem;
+
+ p->ip += 4;
+ val = GetBe32(cur) - p->ip;
+ dest = p->dest;
+ rem = p->destLim - dest;
+ if (rem < 4)
+ {
+ SizeT i;
+ SetUi32(p->temp, val);
+ for (i = 0; i < rem; i++)
+ dest[i] = p->temp[i];
+ p->dest = dest + rem;
+ p->state = BCJ2_DEC_STATE_ORIG_0 + (unsigned)rem;
+ return SZ_OK;
+ }
+ SetUi32(dest, val);
+ p->temp[3] = (Byte)(val >> 24);
+ p->dest = dest + 4;
+ p->state = BCJ2_DEC_STATE_OK;
+ }
+ }
+ */
+
+ for (;;)
+ {
+ if (BCJ2_IS_32BIT_STREAM(p->state))
+ p->state = BCJ2_DEC_STATE_OK;
+ else
+ {
+ if (p->range < kTopValue)
+ {
+ if (p->bufs[BCJ2_STREAM_RC] == p->lims[BCJ2_STREAM_RC])
+ {
+ p->state = BCJ2_STREAM_RC;
+ return SZ_OK;
+ }
+ p->range <<= 8;
+ p->code = (p->code << 8) | *(p->bufs[BCJ2_STREAM_RC])++;
+ }
+
+ {
+ const Byte *src = p->bufs[BCJ2_STREAM_MAIN];
+ const Byte *srcLim;
+ Byte *dest;
+ SizeT num = p->lims[BCJ2_STREAM_MAIN] - src;
+
+ if (num == 0)
+ {
+ p->state = BCJ2_STREAM_MAIN;
+ return SZ_OK;
+ }
+
+ dest = p->dest;
+ if (num > (SizeT)(p->destLim - dest))
+ {
+ num = p->destLim - dest;
+ if (num == 0)
+ {
+ p->state = BCJ2_DEC_STATE_ORIG;
+ return SZ_OK;
+ }
+ }
+
+ srcLim = src + num;
+
+ if (p->temp[3] == 0x0F && (src[0] & 0xF0) == 0x80)
+ *dest = src[0];
+ else for (;;)
+ {
+ Byte b = *src;
+ *dest = b;
+ if (b != 0x0F)
+ {
+ if ((b & 0xFE) == 0xE8)
+ break;
+ dest++;
+ if (++src != srcLim)
+ continue;
+ break;
+ }
+ dest++;
+ if (++src == srcLim)
+ break;
+ if ((*src & 0xF0) != 0x80)
+ continue;
+ *dest = *src;
+ break;
+ }
+
+ num = src - p->bufs[BCJ2_STREAM_MAIN];
+
+ if (src == srcLim)
+ {
+ p->temp[3] = src[-1];
+ p->bufs[BCJ2_STREAM_MAIN] = src;
+ p->ip += (UInt32)num;
+ p->dest += num;
+ p->state =
+ p->bufs[BCJ2_STREAM_MAIN] ==
+ p->lims[BCJ2_STREAM_MAIN] ?
+ (unsigned)BCJ2_STREAM_MAIN :
+ (unsigned)BCJ2_DEC_STATE_ORIG;
+ return SZ_OK;
+ }
+
+ {
+ UInt32 bound, ttt;
+ CProb *prob;
+ Byte b = src[0];
+ Byte prev = (Byte)(num == 0 ? p->temp[3] : src[-1]);
+
+ p->temp[3] = b;
+ p->bufs[BCJ2_STREAM_MAIN] = src + 1;
+ num++;
+ p->ip += (UInt32)num;
+ p->dest += num;
+
+ prob = p->probs + (unsigned)(b == 0xE8 ? 2 + (unsigned)prev : (b == 0xE9 ? 1 : 0));
+
+ _IF_BIT_0
+ {
+ _UPDATE_0
+ continue;
+ }
+ _UPDATE_1
+
+ }
+ }
+ }
+
+ {
+ UInt32 val;
+ unsigned cj = (p->temp[3] == 0xE8) ? BCJ2_STREAM_CALL : BCJ2_STREAM_JUMP;
+ const Byte *cur = p->bufs[cj];
+ Byte *dest;
+ SizeT rem;
+
+ if (cur == p->lims[cj])
+ {
+ p->state = cj;
+ break;
+ }
+
+ val = GetBe32(cur);
+ p->bufs[cj] = cur + 4;
+
+ p->ip += 4;
+ val -= p->ip;
+ dest = p->dest;
+ rem = p->destLim - dest;
+
+ if (rem < 4)
+ {
+ p->temp[0] = (Byte)val; if (rem > 0) dest[0] = (Byte)val; val >>= 8;
+ p->temp[1] = (Byte)val; if (rem > 1) dest[1] = (Byte)val; val >>= 8;
+ p->temp[2] = (Byte)val; if (rem > 2) dest[2] = (Byte)val; val >>= 8;
+ p->temp[3] = (Byte)val;
+ p->dest = dest + rem;
+ p->state = BCJ2_DEC_STATE_ORIG_0 + (unsigned)rem;
+ break;
+ }
+
+ SetUi32(dest, val);
+ p->temp[3] = (Byte)(val >> 24);
+ p->dest = dest + 4;
+ }
+ }
+
+ if (p->range < kTopValue && p->bufs[BCJ2_STREAM_RC] != p->lims[BCJ2_STREAM_RC])
+ {
+ p->range <<= 8;
+ p->code = (p->code << 8) | *(p->bufs[BCJ2_STREAM_RC])++;
+ }
+
+ return SZ_OK;
+}
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