Ron wrote:
Hi Folks. I would have thought that with -Os the code below should work.
static volatile char* Ptr;
.
.
static Send(char* p)
{
if (p)
{
while (Ptr != NULL) {;}
Ptr = p;
UDR1 = *Ptr++;
}
}
.
.
SIGNAL(SIG_UART1_TRANS)
{
if (*Ptr == '\0')
Ptr = NULL;
else
UDR1 = *Ptr++;
}
However, the while loop becomes:
LDS R24,0x018D
LDS R25,0x018E
SBIW R24,0x00
BRNE PC-0x01
The code is as expected with -O0. Version is 3.4.6. Something I'm
missing?
Probably.
You didn't declare Ptr to be volatile.
Instead you declared Ptr to *point to* a volatile char.
So in the while loop (while you're comparing Ptr to NULL) there's no
reason to re-read Ptr because it's not volatile.
--
Ned Konz
[EMAIL PROTECTED]
http://bike-nomad.com
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