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Issue 13010: use VRP for static asserts
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@lionello
lionello committed Jul 1, 2014
1 parent 59f088f commit 8292395
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Showing 2 changed files with 118 additions and 47 deletions.
159 changes: 112 additions & 47 deletions src/constfold.c
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Original file line number Diff line number Diff line change
Expand Up @@ -900,6 +900,62 @@ Expression *Identity(TOK op, Type *type, Expression *e1, Expression *e2)
}


static bool unsignedCmp(d_uns64 n1, TOK op, d_uns64 n2)
{
switch (op)
{
case TOKlt: return n1 < n2;
case TOKle: return n1 <= n2;
case TOKgt: return n1 > n2;
case TOKge: return n1 >= n2;

case TOKleg: return 1;
case TOKlg: return n1 != n2;
case TOKunord: return 0;
case TOKue: return n1 == n2;
case TOKug: return n1 > n2;
case TOKuge: return n1 >= n2;
case TOKul: return n1 < n2;
case TOKule: return n1 <= n2;

default:
assert(0);
}
}

static bool signedCmp(sinteger_t n1, TOK op, sinteger_t n2)
{
switch (op)
{
case TOKlt: return n1 < n2;
case TOKle: return n1 <= n2;
case TOKgt: return n1 > n2;
case TOKge: return n1 >= n2;

case TOKleg: return 1;
case TOKlg: return n1 != n2;
case TOKunord: return 0;
case TOKue: return n1 == n2;
case TOKug: return n1 > n2;
case TOKuge: return n1 >= n2;
case TOKul: return n1 < n2;
case TOKule: return n1 <= n2;

default:
assert(0);
}
}

static bool integerCmp(bool anyunsigned, sinteger_t n1, TOK op, sinteger_t n2)
{
/* Do an unsigned comparison if any of the integers is unsigned. */
if (anyunsigned)
return unsignedCmp(n1, op, n2);
else
return signedCmp(n1, op, n2);
}


Expression *Cmp(TOK op, Type *type, Expression *e1, Expression *e2)
{ Expression *e;
Loc loc = e1->loc;
Expand Down Expand Up @@ -943,16 +999,20 @@ Expression *Cmp(TOK op, Type *type, Expression *e1, Expression *e2)
assert(0);
}
}
else if (e1->isConst() != 1 || e2->isConst() != 1)
return EXP_CANT_INTERPRET;
else if (e1->type->isreal())
{
if (e1->isConst() != 1 || e2->isConst() != 1)
return EXP_CANT_INTERPRET;

r1 = e1->toReal();
r2 = e2->toReal();
goto L1;
}
else if (e1->type->isimaginary())
{
if (e1->isConst() != 1 || e2->isConst() != 1)
return EXP_CANT_INTERPRET;

r1 = e1->toImaginary();
r2 = e2->toImaginary();
L1:
Expand Down Expand Up @@ -1007,57 +1067,62 @@ Expression *Cmp(TOK op, Type *type, Expression *e1, Expression *e2)
{
assert(0);
}
else
{ sinteger_t n1;
sinteger_t n2;

n1 = e1->toInteger();
n2 = e2->toInteger();
if (e1->type->isunsigned() || e2->type->isunsigned())
else if (e1->isConst() != 1 || e2->isConst() != 1)
{
/* Use VRP to determine whether the comparison is always true or false. */
bool anyunsigned = (e1->type->isunsigned() || e2->type->isunsigned());
IntRange r1 = getIntRange(e1);
IntRange r2 = getIntRange(e2);
switch (op)
{
switch (op)
{
case TOKlt: n = ((d_uns64) n1) < ((d_uns64) n2); break;
case TOKle: n = ((d_uns64) n1) <= ((d_uns64) n2); break;
case TOKgt: n = ((d_uns64) n1) > ((d_uns64) n2); break;
case TOKge: n = ((d_uns64) n1) >= ((d_uns64) n2); break;

case TOKleg: n = 1; break;
case TOKlg: n = ((d_uns64) n1) != ((d_uns64) n2); break;
case TOKunord: n = 0; break;
case TOKue: n = ((d_uns64) n1) == ((d_uns64) n2); break;
case TOKug: n = ((d_uns64) n1) > ((d_uns64) n2); break;
case TOKuge: n = ((d_uns64) n1) >= ((d_uns64) n2); break;
case TOKul: n = ((d_uns64) n1) < ((d_uns64) n2); break;
case TOKule: n = ((d_uns64) n1) <= ((d_uns64) n2); break;
case TOKul:
case TOKule:
case TOKlt:
case TOKle:
if (integerCmp(anyunsigned, r1.imax.value, op, r2.imin.value))
n = 1;
else if (integerCmp(anyunsigned, r1.imin.value, op, r2.imax.value))
return EXP_CANT_INTERPRET;
else
n = 0;
break;

default:
assert(0);
}
}
else
{
switch (op)
{
case TOKlt: n = n1 < n2; break;
case TOKle: n = n1 <= n2; break;
case TOKgt: n = n1 > n2; break;
case TOKge: n = n1 >= n2; break;
case TOKug:
case TOKuge:
case TOKgt:
case TOKge:
if (integerCmp(anyunsigned, r1.imin.value, op, r2.imax.value))
n = 1;
else if (integerCmp(anyunsigned, r1.imax.value, op, r2.imin.value))
return EXP_CANT_INTERPRET;
else
n = 0;
break;

case TOKleg: n = 1; break;
case TOKlg: n = n1 != n2; break;
case TOKunord: n = 0; break;
case TOKue: n = n1 == n2; break;
case TOKug: n = n1 > n2; break;
case TOKuge: n = n1 >= n2; break;
case TOKul: n = n1 < n2; break;
case TOKule: n = n1 <= n2; break;
case TOKleg:
n = 1;
break;

default:
assert(0);
}
case TOKunord:
n = 0;
break;

case TOKue:
case TOKlg:
return EXP_CANT_INTERPRET;

default:
assert(0);
}
}
else
{
sinteger_t n1 = e1->toInteger();
sinteger_t n2 = e2->toInteger();

bool anyunsigned = (e1->type->isunsigned() || e2->type->isunsigned());
n = integerCmp(anyunsigned, n1, op, n2);
}
e = new IntegerExp(loc, n, type);
return e;
}
Expand Down
6 changes: 6 additions & 0 deletions test/compilable/testVRP.d
View file
Original file line number Diff line number Diff line change
Expand Up @@ -329,3 +329,9 @@ void test13001(bool unknown)
static assert(!__traits(compiles, b = i + 254));
}
}

void test13010(ubyte value)
{
immutable int i = value;
static assert(i + 1 > 0);
}

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