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- // VirtualDub - Video processing and capture application
- // System library component
- // Copyright (C) 1998-2004 Avery Lee, All Rights Reserved.
- //
- // Beginning with 1.6.0, the VirtualDub system library is licensed
- // differently than the remainder of VirtualDub. This particular file is
- // thus licensed as follows (the "zlib" license):
- //
- // This software is provided 'as-is', without any express or implied
- // warranty. In no event will the authors be held liable for any
- // damages arising from the use of this software.
- //
- // Permission is granted to anyone to use this software for any purpose,
- // including commercial applications, and to alter it and redistribute it
- // freely, subject to the following restrictions:
- //
- // 1. The origin of this software must not be misrepresented; you must
- // not claim that you wrote the original software. If you use this
- // software in a product, an acknowledgment in the product
- // documentation would be appreciated but is not required.
- // 2. Altered source versions must be plainly marked as such, and must
- // not be misrepresented as being the original software.
- // 3. This notice may not be removed or altered from any source
- // distribution.
-
- #include "stdafx.h"
- #include <vd2/system/vdtypes.h>
- #include <vd2/system/debugx86.h>
-
- bool VDIsValidCallX86(const char *buf, int len) {
- // Permissible CALL sequences that we care about:
- //
- // E8 xx xx xx xx CALL near relative
- // FF (group 2) CALL near absolute indirect
- //
- // Minimum sequence is 2 bytes (call eax).
- // Maximum sequence is 7 bytes (call dword ptr [eax+disp32]).
-
- if (len >= 5 && buf[-5] == (char)0xE8)
- return true;
-
- // FF 14 xx CALL [reg32+reg32*scale]
-
- if (len >= 3 && buf[-3] == (char)0xFF && buf[-2]==0x14)
- return true;
-
- // FF 15 xx xx xx xx CALL disp32
-
- if (len >= 6 && buf[-6] == (char)0xFF && buf[-5]==0x15)
- return true;
-
- // FF 00-3F(!14/15) CALL [reg32]
-
- if (len >= 2 && buf[-2] == (char)0xFF && (unsigned char)buf[-1] < 0x40)
- return true;
-
- // FF D0-D7 CALL reg32
-
- if (len >= 2 && buf[-2] == (char)0xFF && (buf[-1]&0xF8) == 0xD0)
- return true;
-
- // FF 50-57 xx CALL [reg32+reg32*scale+disp8]
-
- if (len >= 3 && buf[-3] == (char)0xFF && (buf[-2]&0xF8) == 0x50)
- return true;
-
- // FF 90-97 xx xx xx xx xx CALL [reg32+reg32*scale+disp32]
-
- if (len >= 7 && buf[-7] == (char)0xFF && (buf[-6]&0xF8) == 0x90)
- return true;
-
- return false;
- }
-
- VDInstructionTypeX86 VDGetInstructionTypeX86(const void *p) {
- struct local {
- static bool RangeHitTest(const uint8 *range, uint8 c) {
- while(*range) {
- if (c>=range[0] && c<=range[1])
- return true;
- range += 2;
- }
-
- return false;
- }
- };
-
- VDInstructionTypeX86 type = kX86InstUnknown;
-
- __try {
- unsigned char buf[8];
-
- memcpy(buf, p, 8);
-
- if (buf[0] == 0x0f && buf[1] == 0x0f)
- type = kX86Inst3DNow; // Conveniently, all 3DNow! instructions begin 0F 0F
- else if ((buf[0] == 0xdb || buf[0] == 0xdf) && (buf[1]>=0xe8 && buf[1]<=0xf7))
- type = kX86InstP6; // DB/DF E8-F7: FCOMI/FCOMIP/FUCOMI/FUCOMIP (P6)
- else if ((buf[0]&0xfe)==0xda && (buf[1]&0xe0)==0xc0)
- type = kX86InstP6; // DA/DB C0-DF: FCMOVcc (P6)
- else if (buf[0] == 0x0f && (buf[1]&0xf0)==0x40)
- type = kX86InstP6; // 0F 40-4F: CMOVcc (P6)
- else {
- const unsigned char *s = buf;
- bool bWide = false;
- bool bRepF2 = false;
- bool bRepF3 = false;
-
- // At this point we're down to MMX, SSE, SSE2 -- which makes things simpler
- // as we must see F2 0F, F3 0F, or 0F next. MMX ops use 0F exclusively,
- // some SSE ops use F2, and a few SSE2 ones use F3. If we see 66 on an
- // MMX or SSE op it's automatically SSE2 as it's either a 128-bit MMX op
- // or a double-precision version of an SSE one.
-
- if (*s == 0x66) { // 66h override used by SSE2 and is supposed to be ahead of F2/F3 in encodings
- ++s;
- bWide = true;
- }
-
- if (*s == 0xf2) {
- ++s;
- bRepF2 = true;
- }
-
- if (*s == 0xf3) {
- ++s;
- bRepF3 = true;
- }
-
- if (*s++ == 0x0f) {
- // SSE - 1x, 28-2F, 5x, C2, AE
- // MMX2 - 70, C4-C6, D7, DA, DE, E0, E3, E4, E7, EA, EE, F6, F7
- // MMX - 6x, 7x, Dx, Ex, and Fx except for MMX2
- // SSE2 - C3, SSE ops with 66 or F2, MMX/MMX2 ops with 66/F2/F3
-
- static const uint8 sse_ranges[]={0x10,0x1f,0x28,0x2f,0x50,0x5f,0xc2,0xc2,0xae,0xae,0};
- static const uint8 sse2_ranges[]={0xc3,0xc3,0};
- static const uint8 mmx2_ranges[]={0x70,0x70,0xc4,0xc6,0xd7,0xd7,0xda,0xda,0xde,0xde,0xe0,0xe0,0xe3,0xe4,0xe7,0xe7,0xea,0xea,0xee,0xee,0xf6,0xf7,0};
- static const uint8 mmx_ranges[]={0x60,0x7f,0xd0,0xff,0};
-
- if (local::RangeHitTest(sse_ranges, *s))
- type = (bWide||bRepF2) ? kX86InstSSE2 : kX86InstSSE;
- else if (local::RangeHitTest(sse2_ranges, *s))
- type = kX86InstSSE2;
- else if (local::RangeHitTest(mmx2_ranges, *s))
- type = (bWide||bRepF2||bRepF3) ? kX86InstSSE2 : kX86InstMMX2;
- else if (local::RangeHitTest(mmx_ranges, *s))
- type = (bWide||bRepF2||bRepF3) ? kX86InstSSE2 : kX86InstMMX;
- }
- }
- } __except(1) {
- }
- return type;
- }
-