зеркало из https://github.com/mozilla/pjs.git
first pass at defining the structure needed to solve this problem
This commit is contained in:
kandrot%netscape.com
Родитель
1cf42d06be
Коммит
8ed0f72d48
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@ -170,6 +170,270 @@ st_type(const char* type)
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}
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}
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//----------------------------------------------------------------------
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int DIGIT_MAP[256] = {
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0, 0, 0, 0, 0, 0, 0, 0, // 0x00 - 0x07
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1, 1, 1, 1, 1, 1, 1, 1,
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2, 2, 2, 2, 2, 2, 2, 2,
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3, 3, 3, 3, 3, 3, 3, 3,
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4, 4, 4, 4, 4, 4, 4, 4,
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5, 5, 5, 5, 5, 5, 5, 5,
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6, 6, 6, 6, 6, 6, 6, 6,
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7, 7, 7, 7, 7, 7, 7, 7, // 0x38 - 0x3f
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0, 0, 0, 0, 0, 0, 0, 0, // 0x40 - 0x47
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1, 1, 1, 1, 1, 1, 1, 1,
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2, 2, 2, 2, 2, 2, 2, 2,
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3, 3, 3, 3, 3, 3, 3, 3,
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4, 4, 4, 4, 4, 4, 4, 4,
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5, 5, 5, 5, 5, 5, 5, 5,
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6, 6, 6, 6, 6, 6, 6, 6,
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7, 7, 7, 7, 7, 7, 7, 7, // 0x78 - 0x7f
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0, 0, 0, 0, 0, 0, 0, 0, // 0x80 - 0x87
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1, 1, 1, 1, 1, 1, 1, 1,
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2, 2, 2, 2, 2, 2, 2, 2,
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3, 3, 3, 3, 3, 3, 3, 3,
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4, 4, 4, 4, 4, 4, 4, 4,
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5, 5, 5, 5, 5, 5, 5, 5,
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6, 6, 6, 6, 6, 6, 6, 6,
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7, 7, 7, 7, 7, 7, 7, 7, // 0xb8 - 0xbf
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0, 0, 0, 0, 0, 0, 0, 0, // 0xc0 - 0xc7
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1, 1, 1, 1, 1, 1, 1, 1,
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2, 2, 2, 2, 2, 2, 2, 2,
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3, 3, 3, 3, 3, 3, 3, 3,
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4, 4, 4, 4, 4, 4, 4, 4,
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5, 5, 5, 5, 5, 5, 5, 5,
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6, 6, 6, 6, 6, 6, 6, 6,
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7, 7, 7, 7, 7, 7, 7, 7}; // 0xf8 - 0xff
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/*
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* Dceclation of the Instruction types
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*/
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struct CInstruction {
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int isize; // size of the instruction in bytes
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unsigned char idata[8];
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virtual void output( void );
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void hexdump( void );
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};
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void CInstruction::output( void )
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{
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cout << "Dummy Instruction\n";
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}
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struct CPush:CInstruction {
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CPush( unsigned char *theCode );
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virtual void output( void );
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};
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struct CCmp:CInstruction {
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CCmp( unsigned char *theCode );
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virtual void output( void );
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};
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struct CSub:CInstruction {
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CSub( unsigned char *theCode );
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virtual void output( void );
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};
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struct CBadOpCode:CInstruction {
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CBadOpCode( unsigned char *theCode );
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virtual void output( void );
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};
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void CInstruction::hexdump( void )
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{
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int instrSize = isize;
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while (instrSize)
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{
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cout.form("%02x ", idata[isize - instrSize]);
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instrSize--;
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}
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cout << "\n";
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}
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/* CPush */
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CPush::CPush( unsigned char *theCode )
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{
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switch( *theCode )
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{
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case 0x06:
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isize = 1;
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break;
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case 0x0e:
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isize = 1;
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break;
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case 0x0f:
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isize = 2;
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break;
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case 0x16:
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isize = 1;
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break;
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case 0x1e:
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isize = 1;
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break;
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case 0x68:
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isize = 5;
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break;
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case 0x6a:
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isize = 2;
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break;
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case 0x50:
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case 0x51:
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case 0x52:
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case 0x53:
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case 0x54:
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case 0x55:
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case 0x56:
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case 0x57:
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isize = 1;
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break;
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case 0xFF:
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isize = 2; // at least 2!
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break;
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}
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memcpy( idata, theCode, isize );
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}
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void CPush::output( void )
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{
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cout << "push r\n";
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}
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/* CCmp */
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CCmp::CCmp( unsigned char *theCode )
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{
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isize = 4;
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memcpy( idata, theCode, isize );
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}
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void CCmp::output( void )
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{
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cout << "cmp imm8,off(r)\n";
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}
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/* CSub */
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CSub::CSub( unsigned char *theCode )
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{
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isize = 3;
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memcpy( idata, theCode, isize );
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}
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void CSub::output( void )
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{
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cout << "sub r,imm8\n";
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}
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/* CBadOpCode */
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CBadOpCode::CBadOpCode( unsigned char *theCode )
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{
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isize = 2;
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memcpy( idata, theCode, isize );
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}
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void CBadOpCode::output( void )
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{
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cout << "*** Bad OpCode ";
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cout.form( "%02X %02X ***\n", *idata, *(idata+1) );
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}
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CInstruction* get_next_instruction( unsigned char *theCode )
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{
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CInstruction *retInstr;
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switch (*theCode)
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{
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case 0x55:
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retInstr = new CPush( theCode );
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break;
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case 0x83:
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switch (DIGIT_MAP[*(theCode+1)])
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{
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case 5:
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retInstr = new CSub( theCode );
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break;
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case 7:
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retInstr = new CCmp( theCode );
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break;
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default:
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retInstr = new CBadOpCode( theCode );
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break;
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}
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break;
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case 0x88:
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case 0x89:
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case 0x8a:
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case 0x8b:
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case 0x8c:
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case 0x8e:
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case 0xc7:
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// retInstr = new CMov( theCode );
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break;
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case 0x7e:
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case 0xeb:
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// retInstr = new CJmp( theCode );
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break;
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default:
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retInstr = new CBadOpCode( theCode );
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break;
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}
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return retInstr;
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}
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/*
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* Takes the compile intel code and tries to optimize it.
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*
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* returns the number of bytes smaller the new code is.
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*/
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long process_function( unsigned char *theCode, long codeSize )
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{
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long saved=0;
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while (codeSize > 0)
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{
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CInstruction *instr = get_next_instruction( theCode );
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int instrSize = instr->isize;
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theCode += instrSize;
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codeSize -= instrSize;
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instr->hexdump();
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instr->output();
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delete instr;
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}
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return 0;
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}
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//----------------------------------------------------------------------
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typedef vector<elf_symbol> elf_symbol_table;
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@ -200,6 +464,7 @@ process_mapping(char* mapping, size_t size)
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}
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else if (name == ".text") {
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textsh = shdrs + i;
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textndx = i;
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}
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else if (name == ".strtab") {
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strtabsh = shdrs + i;
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@ -216,55 +481,24 @@ process_mapping(char* mapping, size_t size)
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// find the symbol table
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int nentries = symtabsh->sh_size / sizeof(Elf32_Sym);
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Elf32_Sym* symtab = reinterpret_cast<Elf32_Sym*>(mapping + symtabsh->sh_offset);
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// look for symbols in the .text section
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// look for code in the .text section
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elf_text_map textmap;
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#if 1
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long bytesSaved = 0;
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for (int i = 0; i < nentries; ++i) {
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const Elf32_Sym* sym = symtab + i;
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cout << sym->st_name << "\n";
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if (sym->st_shndx == textndx &&
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// ELF32_ST_TYPE(sym->st_info) == st_type(opt_type) &&
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sym->st_size) {
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if ( sym->st_shndx == textndx && sym->st_size)
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{
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basic_string<char> funcname(sym->st_name + strtab, sym->st_size);
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basic_string<char> functext(text + sym->st_value - textaddr, sym->st_size);
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cout << functext << "\n";
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elf_symbol_table& syms = textmap[functext];
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if (syms.end() == find(syms.begin(), syms.end(), elf_symbol(*sym)))
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syms.insert(syms.end(), *sym);
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if (gDebug) cout << funcname << "\n\n";
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if (gDebug) hexdump(cout,functext.data(),sym->st_size);
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bytesSaved += process_function( (unsigned char *)functext.data(), sym->st_size );
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}
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}
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#endif
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int uniquebytes = 0, totalbytes = 0;
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int uniquecount = 0, totalcount = 0;
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for (elf_text_map::const_iterator entry = textmap.begin();
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entry != textmap.end();
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++entry) {
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const elf_symbol_table& syms = entry->second;
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cout << "H2\n";
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if (syms.size() <= 1)
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continue;
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int sz = syms.begin()->st_size;
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uniquebytes += sz;
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totalbytes += sz * syms.size();
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uniquecount += 1;
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totalcount += syms.size();
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for (elf_symbol_table::const_iterator sym = syms.begin(); sym != syms.end(); ++sym)
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cout << strtab + sym->st_name << endl;
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dec(cout);
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cout << syms.size() << " copies of " << sz << " bytes";
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cout << " (" << ((syms.size() - 1) * sz) << " redundant bytes)" << endl;
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hexdump(cout, entry->first.data(), entry->first.size());
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cout << endl;
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}
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dec(cout);
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cout << "bytes unique=" << uniquebytes << ", total=" << totalbytes << endl;
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cout << "entries unique=" << uniquecount << ", total=" << totalcount << endl;
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cout << "Code size reduction of " << bytesSaved << "\n";
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}
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void
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