You can ignore that last email. I think I finally found where the
problem is. In the main program:
extern void abort (void);
int main ()
{
signed char a = -1;
_Sat unsigned _Fract b = a;
if (b != 0.0ur)
abort();
return 0;
}
If I compile with -O0, I see:
li $2,-1 # 0xffffffffffffffff
sb $2,24($fp)
lbu $4,24($fp)
jal __satfractqiuhq
We put -1 in register $2, store the byte, then load the byte as an
unsigned char instead of a signed char. When TARGET_PROMOTE_PROTOTYPES
was defined it didn't matter because __satfractqiuhq did another sign
extend before using the value. When I got rid of
TARGET_PROMOTE_PROTOTYPES, that extra sign extend went away and the fact
that we are doing a 'lbu' unsigned load instead of a 'lb' signed byte
load triggered the bug. Now I just need to find out why we are doing an
lbu instead of an lb.
Steve Ellcey
[email protected]
