This patch fixes a thinko in avr_function_arg_advance.
Without the patch, following code will report false positive for
passing args in fixed regs like:
error: Register r0 is needed to pass a parameter but is fixed
error: Register r1 is needed to pass a parameter but is fixed
This is the code:
typedef struct
{
char c[18];
} S;
typedef struct
{
char c[26];
} T;
char foo (S b, T a)
{
return b.c[9];
}
The patch also uses same constraint for cfun->machine->sibcall_fails
(even though it would not hut to have false positived there).
Johann
--
* config/avr/avr.c (avr_function_arg_advance): Fix thinko about
when a value is actually passed in regs.
Index: config/avr/avr.c
===================================================================
--- config/avr/avr.c (Revision 174701)
+++ config/avr/avr.c (Arbeitskopie)
@@ -1784,7 +1784,8 @@ avr_function_arg_advance (CUMULATIVE_ARG
a function must not pass arguments in call-saved regs in order to get
tail-called. */
- if (cum->regno >= 0
+ if (cum->regno >= 8
+ && cum->nregs >= 0
&& !call_used_regs[cum->regno])
{
/* FIXME: We ship info on failing tail-call in struct machine_function.
@@ -1800,7 +1801,8 @@ avr_function_arg_advance (CUMULATIVE_ARG
user has fixed a GPR needed to pass an argument, an (implicit) function
call would clobber that fixed register. See PR45099 for an example. */
- if (cum->regno >= 0)
+ if (cum->regno >= 8
+ && cum->nregs >= 0)
{
int regno;
