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Fixed bitwise shift with numeric constant operand(s).

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This commit is contained in:
acqn 2022-02-16 20:10:54 +08:00
parent d006317b0e
commit 14988f5dda
1 changed files with 25 additions and 29 deletions
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54
src/cc65/shiftexpr.c
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@ -64,11 +64,11 @@ void ShiftExpr (struct ExprDesc* Expr)
CodeMark Mark1;
CodeMark Mark2;
token_t Tok; /* The operator token */
const Type* EffType; /* Effective lhs type */
const Type* ResultType; /* Type of the result */
unsigned ExprBits; /* Bits of the lhs operand */
unsigned GenFlags; /* Generator flags */
unsigned ltype;
int lconst; /* Operand is a constant */
int rconst; /* Operand is a constant */
@ -92,7 +92,7 @@ void ShiftExpr (struct ExprDesc* Expr)
NextToken ();
/* Get the type of the result */
ResultType = EffType = IntPromotion (Expr->Type);
ResultType = IntPromotion (Expr->Type);
/* Prepare the code generator flags */
GenFlags = TypeOf (ResultType);
@ -103,7 +103,8 @@ void ShiftExpr (struct ExprDesc* Expr)
/* Get the lhs on stack */
GetCodePos (&Mark1);
ltype = TypeOf (Expr->Type);
if (ED_IsConstAbs (Expr)) {
lconst = ED_IsConstAbs (Expr);
if (lconst) {
/* Constant value */
GetCodePos (&Mark2);
g_push (ltype | CF_CONST, Expr->IVal);
@ -115,7 +116,7 @@ void ShiftExpr (struct ExprDesc* Expr)
}
/* Get the right hand side */
ExprWithCheck (hie8, &Expr2);
MarkedExprWithCheck (hie8, &Expr2);
/* Check the type of the rhs */
if (!IsClassInt (Expr2.Type)) {
@ -124,7 +125,7 @@ void ShiftExpr (struct ExprDesc* Expr)
}
/* Check for a constant right side expression */
rconst = ED_IsConstAbs (&Expr2);
rconst = ED_IsConstAbs (&Expr2) && ED_CodeRangeIsEmpty (&Expr2);
if (!rconst) {
/* Not constant, load into the primary */
@ -154,31 +155,32 @@ void ShiftExpr (struct ExprDesc* Expr)
}
/* If the shift count is zero, nothing happens */
if (Expr2.IVal == 0) {
/* If the shift count is zero, nothing happens. If the left hand
** side is a constant, the result is constant.
*/
if (Expr2.IVal == 0 || lconst) {
/* Result is already in Expr, remove the generated code */
RemoveCode (&Mark1);
/* Set the type */
Expr->Type = ResultType;
/* Done */
goto Next;
}
if (lconst) {
/* If the left hand side is a constant, the result is constant */
if (ED_IsConstAbs (Expr)) {
/* Evaluate the result */
switch (Tok) {
case TOK_SHL: Expr->IVal <<= Expr2.IVal; break;
case TOK_SHR: Expr->IVal >>= Expr2.IVal; break;
default: /* Shutup gcc */ break;
}
/* Evaluate the result */
switch (Tok) {
case TOK_SHL: Expr->IVal <<= Expr2.IVal; break;
case TOK_SHR: Expr->IVal >>= Expr2.IVal; break;
default: /* Shutup gcc */ break;
/* Limit the calculated value to the range of its type */
LimitExprValue (Expr);
}
/* Both operands are constant, remove the generated code */
/* Result is already got, remove the generated code */
RemoveCode (&Mark1);
/* Done */
goto Next;
continue;
}
/* If we're shifting an integer or unsigned to the right, the lhs
@ -188,13 +190,12 @@ void ShiftExpr (struct ExprDesc* Expr)
** shift count is zero, we're done.
*/
if (Tok == TOK_SHR &&
IsTypeInt (Expr->Type) &&
IsClassInt (Expr->Type) &&
SizeOf (Expr->Type) == SIZEOF_INT &&
ED_IsLVal (Expr) &&
ED_IsLocQuasiConst (Expr) &&
Expr2.IVal >= 8) {
const Type* OldType;
/* Increase the address by one and decrease the shift count */
++Expr->IVal;
Expr2.IVal -= 8;
@ -202,7 +203,6 @@ void ShiftExpr (struct ExprDesc* Expr)
/* Replace the type of the expression temporarily by the
** corresponding char type.
*/
OldType = Expr->Type;
if (IsSignUnsigned (Expr->Type)) {
Expr->Type = type_uchar;
} else {
@ -215,9 +215,6 @@ void ShiftExpr (struct ExprDesc* Expr)
/* Generate again code for the load, this time with the new type */
LoadExpr (CF_NONE, Expr);
/* Reset the type */
Expr->Type = OldType;
/* If the shift count is now zero, we're done */
if (Expr2.IVal == 0) {
/* Be sure to mark the value as in the primary */
@ -238,7 +235,6 @@ MakeRVal:
/* We have an rvalue in the primary now */
ED_FinalizeRValLoad (Expr);
Next:
/* Set the type of the result */
Expr->Type = ResultType;
}