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- #include "dcc.h"
- #include "mov_idioms.h"
- using namespace std;
- /*****************************************************************************
- * idiom 14 - Long uint16_t assign
- * MOV regL, mem/reg
- * XOR regH, regH
- * Eg: MOV ax, di
- * XOR dx, dx
- * => MOV dx:ax, di
- * Note: only the following combinations are allowed:
- * dx:ax
- * cx:bx
- * this is to remove the possibility of making errors in situations
- * like this:
- * MOV dx, offH
- * MOV ax, offL
- * XOR cx, cx
- * Found in Borland Turbo C, used for division of unsigned integer
- * operands.
- ****************************************************************************/
- bool Idiom14::match(iICODE pIcode)
- {
- if(distance(pIcode,m_end)<2)
- return false;
- m_icodes[0]=pIcode++;
- m_icodes[1]=pIcode++;
- /* Check for regL */
- m_regL = m_icodes[0]->ll()->dst.regi;
- if (not m_icodes[0]->ll()->testFlags(I) && ((m_regL == rAX) || (m_regL ==rBX)))
- {
- /* Check for XOR regH, regH */
- if (m_icodes[1]->ll()->match(iXOR) && not m_icodes[1]->ll()->testFlags(I))
- {
- m_regH = m_icodes[1]->ll()->dst.regi;
- if (m_regH == m_icodes[1]->ll()->src.regi)
- {
- if ((m_regL == rAX) && (m_regH == rDX))
- return true;
- if ((m_regL == rBX) && (m_regH == rCX))
- return true;
- }
- }
- }
- return false;
- }
- int Idiom14::action()
- {
- int idx;
- COND_EXPR *lhs,*rhs;
- idx = m_func->localId.newLongReg (TYPE_LONG_SIGN, m_regH, m_regL, m_icodes[0]);
- lhs = COND_EXPR::idLongIdx (idx);
- m_icodes[0]->setRegDU( m_regH, eDEF);
- rhs = COND_EXPR::id (*m_icodes[0], SRC, m_func, m_icodes[0], *m_icodes[0], NONE);
- m_icodes[0]->setAsgn(lhs, rhs);
- m_icodes[1]->invalidate();
- return 2;
- }
- /*****************************************************************************
- * idiom 13 - uint16_t assign
- * MOV regL, mem
- * MOV regH, 0
- * Eg: MOV al, [bp-2]
- * MOV ah, 0
- * => MOV ax, [bp-2]
- * Found in Borland Turbo C, used for multiplication and division of
- * uint8_t operands (ie. they need to be extended to words).
- ****************************************************************************/
- bool Idiom13::match(iICODE pIcode)
- {
- if(distance(pIcode,m_end)<2)
- return false;
- m_icodes[0]=pIcode++;
- m_icodes[1]=pIcode++;
- m_loaded_reg = 0;
- uint8_t regi;
- /* Check for regL */
- regi = m_icodes[0]->ll()->dst.regi;
- if (not m_icodes[0]->ll()->testFlags(I) && (regi >= rAL) && (regi <= rBH))
- {
- /* Check for MOV regH, 0 */
- if (m_icodes[1]->ll()->match(iMOV) && m_icodes[1]->ll()->testFlags(I) && (m_icodes[1]->ll()->src.op() == 0))
- {
- if (m_icodes[1]->ll()->dst.regi == (regi + 4)) //TODO: based on distance between AH-AL,BH-BL etc.
- {
- m_loaded_reg=(regi - rAL + rAX);
- return true;
- }
- }
- }
- return false;
- }
- int Idiom13::action()
- {
- COND_EXPR *lhs,*rhs;
- lhs = COND_EXPR::idReg (m_loaded_reg, 0, &m_func->localId);
- m_icodes[0]->setRegDU( m_loaded_reg, eDEF);
- m_icodes[0]->du1.numRegsDef--; /* prev uint8_t reg def */
- rhs = COND_EXPR::id (*m_icodes[0], SRC, m_func, m_icodes[0], *m_icodes[0], NONE);
- m_icodes[0]->setAsgn(lhs, rhs);
- m_icodes[1]->invalidate();
- return 2;
- }
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