mirror of
https://github.com/cc65/cc65.git
synced 2025-01-13 09:31:53 +00:00
Fixed and improved the code for compares. Before, compares of chars to a
constant where sometimes passed down to the code generator in a way that caused wrong code to be generated. This change may go into 2.13 after some testing. git-svn-id: svn://svn.cc65.org/cc65/trunk@4743 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
uz
parent
4cd7eec075
commit
2bb2d97ab0
182
src/cc65/expr.c
182
src/cc65/expr.c
@ -109,12 +109,13 @@ void ExprWithCheck (void (*Func) (ExprDesc*), ExprDesc* Expr)
|
||||
/* Do some checks if code generation is still constistent */
|
||||
if (StackPtr != OldSP) {
|
||||
if (Debug) {
|
||||
fprintf (stderr,
|
||||
"Code generation messed up!\n"
|
||||
"StackPtr is %d, should be %d",
|
||||
StackPtr, OldSP);
|
||||
Error ("Code generation messed up: "
|
||||
"StackPtr is %d, should be %d",
|
||||
StackPtr, OldSP);
|
||||
} else {
|
||||
Internal ("StackPtr is %d, should be %d\n", StackPtr, OldSP);
|
||||
Internal ("Code generation messed up: "
|
||||
"StackPtr is %d, should be %d",
|
||||
StackPtr, OldSP);
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -255,6 +256,18 @@ void PushAddr (const ExprDesc* Expr)
|
||||
|
||||
|
||||
|
||||
static void WarnConstCompareResult (void)
|
||||
/* If the result of a comparison is constant, this is suspicious when not in
|
||||
* preprocessor mode.
|
||||
*/
|
||||
{
|
||||
if (!Preprocessing) {
|
||||
Warning ("Result of comparison is constant");
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
/*****************************************************************************/
|
||||
/* code */
|
||||
/*****************************************************************************/
|
||||
@ -1904,18 +1917,23 @@ static void hie_compare (const GenDesc* Ops, /* List of generators */
|
||||
/* Helper function for the compare operators */
|
||||
{
|
||||
ExprDesc Expr2;
|
||||
CodeMark Mark0;
|
||||
CodeMark Mark1;
|
||||
CodeMark Mark2;
|
||||
const GenDesc* Gen;
|
||||
token_t Tok; /* The operator token */
|
||||
token_t Tok; /* The operator token */
|
||||
unsigned ltype;
|
||||
int rconst; /* Operand is a constant */
|
||||
|
||||
|
||||
GetCodePos (&Mark0);
|
||||
hienext (Expr);
|
||||
|
||||
while ((Gen = FindGen (CurTok.Tok, Ops)) != 0) {
|
||||
|
||||
/* Remember the generator function */
|
||||
void (*GenFunc) (unsigned, unsigned long) = Gen->Func;
|
||||
|
||||
/* Remember the operator token, then skip it */
|
||||
Tok = CurTok.Tok;
|
||||
NextToken ();
|
||||
@ -1971,9 +1989,7 @@ static void hie_compare (const GenDesc* Ops, /* List of generators */
|
||||
/* If the result is constant, this is suspicious when not in
|
||||
* preprocessor mode.
|
||||
*/
|
||||
if (!Preprocessing) {
|
||||
Warning ("Result of comparison is constant");
|
||||
}
|
||||
WarnConstCompareResult ();
|
||||
|
||||
/* Both operands are constant, remove the generated code */
|
||||
RemoveCode (&Mark1);
|
||||
@ -2011,7 +2027,7 @@ static void hie_compare (const GenDesc* Ops, /* List of generators */
|
||||
}
|
||||
}
|
||||
|
||||
} else {
|
||||
} else {
|
||||
|
||||
/* If the right hand side is constant, and the generator function
|
||||
* expects the lhs in the primary, remove the push of the primary
|
||||
@ -2026,27 +2042,139 @@ static void hie_compare (const GenDesc* Ops, /* List of generators */
|
||||
}
|
||||
}
|
||||
|
||||
/* Determine the type of the operation result. If the left
|
||||
* operand is of type char and the right is a constant, or
|
||||
* if both operands are of type char, we will encode the
|
||||
* operation as char operation. Otherwise the default
|
||||
* promotions are used.
|
||||
*/
|
||||
if (IsTypeChar (Expr->Type) && (IsTypeChar (Expr2.Type) || rconst)) {
|
||||
flags |= CF_CHAR;
|
||||
if (IsSignUnsigned (Expr->Type) || IsSignUnsigned (Expr2.Type)) {
|
||||
flags |= CF_UNSIGNED;
|
||||
}
|
||||
if (rconst) {
|
||||
flags |= CF_FORCECHAR;
|
||||
}
|
||||
/* Determine the type of the operation. */
|
||||
if (IsTypeChar (Expr->Type) && rconst) {
|
||||
|
||||
/* Left side is unsigned char, right side is constant */
|
||||
int LeftSigned = IsSignSigned (Expr->Type);
|
||||
int RightSigned = IsSignSigned (Expr2.Type);
|
||||
|
||||
/* Determine the minimum and maximum values */
|
||||
int LeftMin, LeftMax;
|
||||
if (LeftSigned) {
|
||||
LeftMin = -128;
|
||||
LeftMax = 127;
|
||||
} else {
|
||||
LeftMin = 0;
|
||||
LeftMax = 255;
|
||||
}
|
||||
/* An integer value is always represented as a signed in the
|
||||
* ExprDesc structure. This may lead to false results below,
|
||||
* if it is actually unsigned, but interpreted as signed
|
||||
* because of the representation. Fortunately, in this case,
|
||||
* the actual value doesn't matter, since it's always greater
|
||||
* than what can be represented in a char. So correct the
|
||||
* value accordingly.
|
||||
*/
|
||||
if (!RightSigned && Expr2.IVal < 0) {
|
||||
/* Correct the value so it is an unsigned. It will then
|
||||
* anyway match one of the cases below.
|
||||
*/
|
||||
Expr2.IVal = LeftMax + 1;
|
||||
}
|
||||
|
||||
/* Comparing a char against a constant may have a constant
|
||||
* result.
|
||||
*/
|
||||
switch (Tok) {
|
||||
|
||||
case TOK_EQ:
|
||||
if (Expr2.IVal < LeftMin || Expr2.IVal > LeftMax) {
|
||||
ED_MakeConstAbsInt (Expr, 0);
|
||||
WarnConstCompareResult ();
|
||||
RemoveCode (&Mark0);
|
||||
goto Done;
|
||||
}
|
||||
break;
|
||||
|
||||
case TOK_NE:
|
||||
if (Expr2.IVal < LeftMin || Expr2.IVal > LeftMax) {
|
||||
ED_MakeConstAbsInt (Expr, 1);
|
||||
WarnConstCompareResult ();
|
||||
RemoveCode (&Mark0);
|
||||
goto Done;
|
||||
}
|
||||
break;
|
||||
|
||||
case TOK_LT:
|
||||
if (Expr2.IVal <= LeftMin || Expr2.IVal > LeftMax) {
|
||||
ED_MakeConstAbsInt (Expr, Expr2.IVal > LeftMax);
|
||||
WarnConstCompareResult ();
|
||||
RemoveCode (&Mark0);
|
||||
goto Done;
|
||||
}
|
||||
break;
|
||||
|
||||
case TOK_LE:
|
||||
if (Expr2.IVal < LeftMin || Expr2.IVal >= LeftMax) {
|
||||
ED_MakeConstAbsInt (Expr, Expr2.IVal >= LeftMax);
|
||||
WarnConstCompareResult ();
|
||||
RemoveCode (&Mark0);
|
||||
goto Done;
|
||||
} else if (!LeftSigned && Expr2.IVal == 0) {
|
||||
/* We can replace this by a compare to zero, because
|
||||
* the value of lhs may never be negative.
|
||||
*/
|
||||
GenFunc = g_eq;
|
||||
}
|
||||
break;
|
||||
|
||||
case TOK_GE:
|
||||
if (Expr2.IVal <= LeftMin || Expr2.IVal > LeftMax) {
|
||||
ED_MakeConstAbsInt (Expr, Expr2.IVal <= LeftMin);
|
||||
WarnConstCompareResult ();
|
||||
RemoveCode (&Mark0);
|
||||
goto Done;
|
||||
}
|
||||
break;
|
||||
|
||||
case TOK_GT:
|
||||
if (Expr2.IVal < LeftMin || Expr2.IVal >= LeftMax) {
|
||||
ED_MakeConstAbsInt (Expr, Expr2.IVal < LeftMin);
|
||||
WarnConstCompareResult ();
|
||||
RemoveCode (&Mark0);
|
||||
goto Done;
|
||||
} else if (!LeftSigned && Expr2.IVal == 0) {
|
||||
/* We can replace this by a compare to zero, because
|
||||
* the value of lhs may never be negative.
|
||||
*/
|
||||
GenFunc = g_ne;
|
||||
}
|
||||
break;
|
||||
|
||||
default:
|
||||
Internal ("hie_compare: got token 0x%X\n", Tok);
|
||||
}
|
||||
|
||||
/* If the result is not already constant (as evaluated in the
|
||||
* switch above), we can execute the operation as a char op,
|
||||
* since the right side constant is in a valid range.
|
||||
*/
|
||||
flags |= (CF_CHAR | CF_FORCECHAR);
|
||||
if (!LeftSigned) {
|
||||
flags |= CF_UNSIGNED;
|
||||
}
|
||||
|
||||
} else if (IsTypeChar (Expr->Type) && IsTypeChar (Expr2.Type) &&
|
||||
GetSignedness (Expr->Type) == GetSignedness (Expr2.Type)) {
|
||||
|
||||
/* Both are chars with the same signedness. We can encode the
|
||||
* operation as a char operation.
|
||||
*/
|
||||
flags |= CF_CHAR;
|
||||
if (rconst) {
|
||||
flags |= CF_FORCECHAR;
|
||||
}
|
||||
if (IsSignUnsigned (Expr->Type)) {
|
||||
flags |= CF_UNSIGNED;
|
||||
}
|
||||
} else {
|
||||
unsigned rtype = TypeOf (Expr2.Type) | (flags & CF_CONST);
|
||||
unsigned rtype = TypeOf (Expr2.Type) | (flags & CF_CONST);
|
||||
flags |= g_typeadjust (ltype, rtype);
|
||||
}
|
||||
|
||||
/* Generate code */
|
||||
Gen->Func (flags, Expr2.IVal);
|
||||
GenFunc (flags, Expr2.IVal);
|
||||
|
||||
/* The result is an rvalue in the primary */
|
||||
ED_MakeRValExpr (Expr);
|
||||
@ -2055,7 +2183,7 @@ static void hie_compare (const GenDesc* Ops, /* List of generators */
|
||||
/* Result type is always int */
|
||||
Expr->Type = type_int;
|
||||
|
||||
/* Condition codes are set */
|
||||
Done: /* Condition codes are set */
|
||||
ED_TestDone (Expr);
|
||||
}
|
||||
}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user