This code should not raise the floating point 'invalid' flag.
---
void foo()
{
     double x;
     x = 2;
     real y;
     y = 7;
     float z;
     z = 4;
}
---
Here is the generated code for 32 bits:

		push	EBP
		mov	EBP,ESP
		sub	ESP,018h
		fld	qword ptr FLAT:.rodata[08h]     // load SNAN - bad!
		fstp	qword ptr -018h[EBP]
		fld	qword ptr FLAT:.rodata[019h]
		fstp	qword ptr -018h[EBP]
		fld	tbyte ptr FLAT:.rodata[02Ah]
		fstp	tbyte ptr -010h[EBP]
		mov	word ptr -6[EBP],0
		fld	tbyte ptr FLAT:.rodata[045h]
		fstp	tbyte ptr -010h[EBP]
		mov	word ptr -6[EBP],0
		fld	float ptr FLAT:.rodata[060h]
		fstp	float ptr -4[EBP]
		fld	float ptr FLAT:.rodata[06Dh]
		fstp	float ptr -4[EBP]
		leave
		ret

The problem is, that the code first assigns SNAN to the variables *by loading
them through the floating point unit*. This makes them trigger an INVALID exception. For this scheme to work, the floating point values would need to be loaded by integer operations.