Expr vc_bvVar32RightShiftExpr(VC vc, Expr sh_amt, Expr child) {
Expr ifpart;
Expr thenpart;
Expr elsepart = vc_trueExpr(vc);
Expr ite = vc_trueExpr(vc);
for(int count=32; count >= 0; count--){
if(count != 32) {
ifpart = vc_eqExpr(vc, sh_amt,
vc_bvConstExprFromInt(vc, 32, count));
thenpart = vc_bvRightShiftExpr(vc, count, child);
ite = vc_iteExpr(vc,ifpart,thenpart,elsepart);
elsepart = ite;
} else {
elsepart = vc_bvConstExprFromInt(vc,32, 0);
}
}
return ite;
}
int main(int argc, char** argv)
{
int width=8;
VC handle = vc_createValidityChecker();
// Create variable "x"
Expr x = vc_varExpr(handle, "x", vc_bvType(handle, width));
// Create bitvector x + x
Expr xPlusx = vc_bvPlusExpr(handle, width, x, x);
// Create bitvector constant 2
Expr two = vc_bvConstExprFromInt(handle, width, 2);
// Create bitvector 2*x
Expr xTimes2 = vc_bvMultExpr(handle, width, two, x);
// Create bool expression x + x = 2*x
Expr equality = vc_eqExpr(handle, xPlusx , xTimes2);
vc_assertFormula(handle, vc_trueExpr(handle) );
// We are asking STP: ∀ x. true → ( x + x = 2*x )
// This should be VALID.
printf("######First Query\n");
handleQuery(handle, equality);
// We are asking STP: ∀ x. true → ( x + x = 2 )
// This should be INVALID.
printf("######Second Query\n");
// Create bool expression x + x = 2
Expr badEquality = vc_eqExpr(handle, xPlusx , two);
handleQuery(handle, badEquality);
// Clean up
vc_Destroy(handle);
return 0;
}
// Boolean expressions
value caml_vc_trueExpr(value vc)
{
CAMLparam1(vc);
CAMLreturn(alloc_Expr(vc_trueExpr(VC_val(vc))));
}