| Message ID | 4DF1149C.3000604@gjlay.de |
|---|---|
| State | New |
| Headers | show |
2011/6/9 Georg-Johann Lay <avr@gjlay.de>: > 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). Approved. Denis.
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;
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.