iropt.c

unix下调试内存泄露的工具源代码

               e2 = IRExpr_Const(IRConst_U64(
                       (e->Iex.Binop.arg1->Iex.Const.con->Ico.U64
                        - e->Iex.Binop.arg2->Iex.Const.con->Ico.U64)));
               break;

            /* -- Mul -- */
            case Iop_Mul32:
               e2 = IRExpr_Const(IRConst_U32(
                       (e->Iex.Binop.arg1->Iex.Const.con->Ico.U32
                        * e->Iex.Binop.arg2->Iex.Const.con->Ico.U32)));
               break;
            case Iop_Mul64:
               e2 = IRExpr_Const(IRConst_U64(
                       (e->Iex.Binop.arg1->Iex.Const.con->Ico.U64
                        * e->Iex.Binop.arg2->Iex.Const.con->Ico.U64)));
               break;

            case Iop_MullS32: {
               /* very paranoid */
               UInt  u32a = e->Iex.Binop.arg1->Iex.Const.con->Ico.U32;
               UInt  u32b = e->Iex.Binop.arg2->Iex.Const.con->Ico.U32;
               Int   s32a = (Int)u32a;
               Int   s32b = (Int)u32b;
               Long  s64a = (Long)s32a;
               Long  s64b = (Long)s32b;
               Long  sres = s64a * s64b;
               ULong ures = (ULong)sres;
               e2 = IRExpr_Const(IRConst_U64(ures));
               break;
            }

            /* -- Shl -- */
            case Iop_Shl32:
               vassert(e->Iex.Binop.arg2->Iex.Const.con->tag == Ico_U8);
               shift = (Int)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U8);
               if (shift >= 0 && shift <= 31)
                  e2 = IRExpr_Const(IRConst_U32(
                          (e->Iex.Binop.arg1->Iex.Const.con->Ico.U32
                           << shift)));
               break;
            case Iop_Shl64:
               vassert(e->Iex.Binop.arg2->Iex.Const.con->tag == Ico_U8);
               shift = (Int)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U8);
               if (shift >= 0 && shift <= 63)
                  e2 = IRExpr_Const(IRConst_U64(
                          (e->Iex.Binop.arg1->Iex.Const.con->Ico.U64
                           << shift)));
               break;

            /* -- Sar -- */
            case Iop_Sar32: {
               /* paranoid ... */
               /*signed*/ Int s32;
               vassert(e->Iex.Binop.arg2->Iex.Const.con->tag == Ico_U8);
               s32   = (Int)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U32);
               shift = (Int)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U8);
               if (shift >= 0 && shift <= 31) {
                  s32 >>=/*signed*/ shift;
                  e2 = IRExpr_Const(IRConst_U32((UInt)s32));
               }
               break;
            }
            case Iop_Sar64: {
               /* paranoid ... */
               /*signed*/ Long s64;
               vassert(e->Iex.Binop.arg2->Iex.Const.con->tag == Ico_U8);
               s64   = (Long)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U64);
               shift = (Int)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U8);
               if (shift >= 0 && shift <= 63) {
                  s64 >>=/*signed*/ shift;
                  e2 = IRExpr_Const(IRConst_U64((ULong)s64));
               }
               break;
            }

            /* -- Shr -- */
            case Iop_Shr32: {
               /* paranoid ... */
               /*unsigned*/ UInt u32;
               vassert(e->Iex.Binop.arg2->Iex.Const.con->tag == Ico_U8);
               u32   = (UInt)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U32);
               shift = (Int)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U8);
               if (shift >= 0 && shift <= 31) {
                  u32 >>=/*unsigned*/ shift;
                  e2 = IRExpr_Const(IRConst_U32(u32));
               }
               break;
            }
            case Iop_Shr64: {
               /* paranoid ... */
               /*unsigned*/ ULong u64;
               vassert(e->Iex.Binop.arg2->Iex.Const.con->tag == Ico_U8);
               u64   = (ULong)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U64);
               shift = (Int)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U8);
               if (shift >= 0 && shift <= 63) {
                  u64 >>=/*unsigned*/ shift;
                  e2 = IRExpr_Const(IRConst_U64(u64));
               }
               break;
            }

            /* -- CmpEQ -- */
            case Iop_CmpEQ32:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       (e->Iex.Binop.arg1->Iex.Const.con->Ico.U32
                        == e->Iex.Binop.arg2->Iex.Const.con->Ico.U32))));
               break;
            case Iop_CmpEQ64:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       (e->Iex.Binop.arg1->Iex.Const.con->Ico.U64
                        == e->Iex.Binop.arg2->Iex.Const.con->Ico.U64))));
               break;

            /* -- CmpNE -- */
            case Iop_CmpNE8:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       ((0xFF & e->Iex.Binop.arg1->Iex.Const.con->Ico.U8)
                        != (0xFF & e->Iex.Binop.arg2->Iex.Const.con->Ico.U8)))));
               break;
            case Iop_CmpNE32:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       (e->Iex.Binop.arg1->Iex.Const.con->Ico.U32
                        != e->Iex.Binop.arg2->Iex.Const.con->Ico.U32))));
               break;
            case Iop_CmpNE64:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       (e->Iex.Binop.arg1->Iex.Const.con->Ico.U64
                        != e->Iex.Binop.arg2->Iex.Const.con->Ico.U64))));
               break;

            /* -- CmpLEU -- */
            case Iop_CmpLE32U:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       ((UInt)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U32)
                        <= (UInt)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U32)))));
               break;

            /* -- CmpLES -- */
            case Iop_CmpLE32S:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       ((Int)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U32)
                        <= (Int)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U32)))));
               break;

            /* -- CmpLTS -- */
            case Iop_CmpLT32S:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       ((Int)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U32)
                        < (Int)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U32)))));
               break;

            /* -- CmpLTU -- */
            case Iop_CmpLT32U:
               e2 = IRExpr_Const(IRConst_U1(toBool(
                       ((UInt)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U32)
                        < (UInt)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U32)))));
               break;

            /* -- CmpORD -- */
            case Iop_CmpORD32S: {
               /* very paranoid */
               UInt  u32a = e->Iex.Binop.arg1->Iex.Const.con->Ico.U32;
               UInt  u32b = e->Iex.Binop.arg2->Iex.Const.con->Ico.U32;
               Int   s32a = (Int)u32a;
               Int   s32b = (Int)u32b;
               Int   r = 0x2; /* EQ */
               if (s32a < s32b) {
                  r = 0x8; /* LT */
               } 
               else if (s32a > s32b) {
                  r = 0x4; /* GT */
               }
               e2 = IRExpr_Const(IRConst_U32(r));
               break;
            }

            /* -- nHLto2n -- */
            case Iop_32HLto64:
               e2 = IRExpr_Const(IRConst_U64(
                       (((ULong)(e->Iex.Binop.arg1->Iex.Const.con->Ico.U32)) << 32)
                       | ((ULong)(e->Iex.Binop.arg2->Iex.Const.con->Ico.U32)) 
                    ));
               break;
            case Iop_64HLto128:
               /* We can't fold this, because there is no way to
                  express he result in IR, but at least pretend to
                  handle it, so as to stop getting blasted with
                  no-rule-for-this-primop messages. */
               break;

            default:
               goto unhandled;
         }

      } else {

         /* other cases (identities, etc) */

         /* Shl64/Shr64(x,0) ==> x */
         if ((e->Iex.Binop.op == Iop_Shl64 || e->Iex.Binop.op == Iop_Shr64)
             && e->Iex.Binop.arg2->tag == Iex_Const
             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U8 == 0) {
            e2 = e->Iex.Binop.arg1;
         } else

         /* Shl32/Shr32(x,0) ==> x */
         if ((e->Iex.Binop.op == Iop_Shl32 || e->Iex.Binop.op == Iop_Shr32)
             && e->Iex.Binop.arg2->tag == Iex_Const
             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U8 == 0) {
            e2 = e->Iex.Binop.arg1;
         } else

         /* Or8(x,0) ==> x */
         if ((e->Iex.Binop.op == Iop_Or8)
             && e->Iex.Binop.arg2->tag == Iex_Const
             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U8 == 0) {
            e2 = e->Iex.Binop.arg1;
         } else

         /* Or16(x,0) ==> x */
         if ((e->Iex.Binop.op == Iop_Or16)
             && e->Iex.Binop.arg2->tag == Iex_Const
             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U16 == 0) {
            e2 = e->Iex.Binop.arg1;
         } else

         /* Or32/Add32(x,0) ==> x */
         if ((e->Iex.Binop.op == Iop_Add32 || e->Iex.Binop.op == Iop_Or32)
             && e->Iex.Binop.arg2->tag == Iex_Const
             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U32 == 0) {
            e2 = e->Iex.Binop.arg1;
         } else

         /* Or64/Add64(x,0) ==> x */
         if ((e->Iex.Binop.op == Iop_Add64 || e->Iex.Binop.op == Iop_Or64)
             && e->Iex.Binop.arg2->tag == Iex_Const
             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U64 == 0) {
            e2 = e->Iex.Binop.arg1;
         } else

         /* And32(x,0xFFFFFFFF) ==> x */
         if (e->Iex.Binop.op == Iop_And32
             && e->Iex.Binop.arg2->tag == Iex_Const
             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U32 == 0xFFFFFFFF) {
            e2 = e->Iex.Binop.arg1;
         } else

         /* And32(x,0) ==> 0 */
         if (e->Iex.Binop.op == Iop_And32
             && e->Iex.Binop.arg2->tag == Iex_Const
             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U32 == 0) {
            e2 = IRExpr_Const(IRConst_U32(0));
         } else

         /* Or32(0,x) ==> x */
         if (e->Iex.Binop.op == Iop_Or32
             && e->Iex.Binop.arg1->tag == Iex_Const
             && e->Iex.Binop.arg1->Iex.Const.con->Ico.U32 == 0) {
            e2 = e->Iex.Binop.arg2;
         } else

         /* Or8/16/32/64(t,t) ==> t, for some IRTemp t */
         /* And8/16/32/64(t,t) ==> t, for some IRTemp t */
         if (   (e->Iex.Binop.op == Iop_And64
              || e->Iex.Binop.op == Iop_And32
              || e->Iex.Binop.op == Iop_And16
              || e->Iex.Binop.op == Iop_And8
              || e->Iex.Binop.op == Iop_Or64
              || e->Iex.Binop.op == Iop_Or32
              || e->Iex.Binop.op == Iop_Or16
              || e->Iex.Binop.op == Iop_Or8)
             && sameIRTemps(e->Iex.Binop.arg1, e->Iex.Binop.arg2)) {
            e2 = e->Iex.Binop.arg1;
         }

         /* Xor8/16/32/64(t,t) ==> 0, for some IRTemp t */
         if (   (e->Iex.Binop.op == Iop_Xor64
              || e->Iex.Binop.op == Iop_Xor32
              || e->Iex.Binop.op == Iop_Xor16
              || e->Iex.Binop.op == Iop_Xor8)
             && sameIRTemps(e->Iex.Binop.arg1, e->Iex.Binop.arg2)) {
            e2 = mkZeroForXor(e->Iex.Binop.op);
         }

      }
   }

   /* Mux0X */
   if (e->tag == Iex_Mux0X
       && e->Iex.Mux0X.cond->tag == Iex_Const) {
      Bool zero;
      /* assured us by the IR type rules */
      vassert(e->Iex.Mux0X.cond->Iex.Const.con->tag == Ico_U8);
      zero = toBool(0 == (0xFF & e->Iex.Mux0X.cond
                                  ->Iex.Const.con->Ico.U8));
      e2 = zero ? e->Iex.Mux0X.expr0 : e->Iex.Mux0X.exprX;
   }

   if (DEBUG_IROPT && e2 != e) {
      vex_printf("FOLD: "); 
      ppIRExpr(e); vex_printf("  ->  ");
      ppIRExpr(e2); vex_printf("\n");
   }

   return e2;

 unhandled:
#  if 0
   vex_printf("\n\n");
   ppIRExpr(e);
   vpanic("fold_Expr: no rule for the above");
#  else
   if (vex_control.iropt_verbosity > 0) {
      vex_printf("vex iropt: fold_Expr: no rule for: ");
      ppIRExpr(e);
      vex_printf("\n");
   }
   return e2;
#  endif
}


/* Apply the subst to a simple 1-level expression -- guaranteed to be
   1-level due to previous flattening pass. */

static IRExpr* subst_Expr ( IRExpr** env, IRExpr* ex )
{
   switch (ex->tag) {
      case Iex_Tmp:
         if (env[(Int)ex->Iex.Tmp.tmp] != NULL) {
            return env[(Int)ex->Iex.Tmp.tmp];
         } else {
            /* not bound in env */
            return ex;
         }

      case Iex_Const:
      case Iex_Get:
         return ex;

      case Iex_GetI:
         vassert(isIRAtom(ex->Iex.GetI.ix));
         return IRExpr_GetI(
            ex->Iex.GetI.descr,
            subst_Expr(env, ex->Iex.GetI.ix),
            ex->Iex.GetI.bias
         );

      case Iex_Binop:
         vassert(isIRAtom(ex->Iex.Binop.arg1));
         vassert(isIRAtom(ex->Iex.Binop.arg2));
         return IRExpr_Binop(
                   ex->Iex.Binop.op,
                   subst_Expr(env, ex->Iex.Binop.arg1),
                   subst_Expr(env, ex->Iex.Binop.arg2)
                );

      case Iex_Unop:
         vassert(isIRAtom(ex->Iex.Unop.arg));
         return IRExpr_Unop(
                   ex->Iex.Unop.op,
                   subst_Expr(env, ex->Iex.Unop.arg)
                );

      case Iex_Load:
         vassert(isIRAtom(ex->Iex.Load.addr));
         return IRExpr_Load(
                   ex->Iex.Load.end,
                   ex->Iex.Load.ty,
                   subst_Expr(env, ex->Iex.Load.addr)
                );

      case Iex_CCall: {
         Int      i;
         IRExpr** args2 = sopyIRExprVec(ex->Iex.CCall.args);
         for (i = 0; args2[i]; i++) {
            vassert(isIRAtom(args2[i]));
            args2[i] = subst_Expr(env, args2[i]);
         }
         return IRExpr_CCall(
                   ex->Iex.CCall.cee,
                   ex->Iex.CCall.retty,
                   args2