> > When I compile this c-File I get this error in the line, where the macro
> > is used:
> >
> > asm operand requires impossible reload
> >
> > What does this error message mean ?
>
> It means that the compiler was unable to find a register to use. It's
> a strange error to get for an asm like this. You may need to put
> together a complete small test case.
I could strip down my file to the attached example. Removing more instructions
or types causes the error to disappear.
In my last mail I forgot to mention that I use the fr30 version of gcc 4.1.1
(3.4.6) did not have the problem. The problem is in line 30.
> > If I compile using the -S switch, the generated assembler file looks fine
> > and the inline assembler is inserted right.
>
> That doesn't make sense. If you get the error without -S, you should
> get the error with -S.
That would indeed be very strange. It was my fault. I was trying with
different options and missed to delete temporary files. With option -da I get
files until *.c.58.shorten
As I can imagine not everybody wants to build fr30 gcc to reproduce the error,
I will post the part of c.58.shorten, that I think is relevant:
(note 188 21 23 ( __chan (expr_list:REG_DEP_TRUE (reg/v/f:SI 9 r9 [orig:43
__chan ] [43])
(const_int 0 [0x0]))) NOTE_INSN_VAR_LOCATION)
(note:HI 23 188 24 ("hal_if3.c") 30)
(insn:HI 24 23 122 hal_if3.c:30 (set (reg:SI 1 r1)
(asm_operands/v:SI ("st r1, @-r15 ;
mov ps, r1 ;
ldi:8 #0x10, %0 ;
and r1, %0 ;
lsr #1, %0 ;
ld @r15+, r1 ;
andccr #0xef
") ("=r") 0 []
[] ("hal_if3.c") 30)) -1 (nil)
(expr_list:REG_UNUSED (reg:SI 1 r1)
(nil)))
(note:HI 122 24 147 NOTE_INSN_DELETED)
(insn 147 122 126 (set (reg:SI 2 r2)
(reg/v/f:SI 9 r9 [orig:43 __chan ] [43])) 6 {movsi_internal} (nil)
(nil))
You see the inline instructions with the %0 placeholder. What wants the
compiler to do next ? As I read the RTL the compiler already choose r2 for
the output variable r. It only has to replace the %0 by r2. What is its
problem here ? Is there happening another reload pass ?
Thank you very much for your help,
Lars
typedef volatile unsigned int hal_virtual_comm_table_t[8];
typedef void (*__comm_if_putc_t)(void* __ch_data, unsigned char __ch);
static __inline__ void __call_COMM_IF_PUTC(hal_virtual_comm_table_t t, unsigned char _p1_) { void *dp = (void *)t[0]; ((__comm_if_putc_t)(t[3]))(dp, _p1_); }
extern volatile unsigned int hal_virtual_vector_table[64];
typedef hal_virtual_comm_table_t *__call_if_console_procs_t;
typedef hal_virtual_comm_table_t *__call_if_debug_procs_t;
static __inline__ __call_if_debug_procs_t __call_vv_CYGNUM_CALL_IF_DEBUG_PROCS(void) { return ((__call_if_debug_procs_t)hal_virtual_vector_table[6]); }
static char __mangler_line[100];
static int __mangler_pos = 0;
void
cyg_hal_diag_mangler_gdb_flush(void* __ch_data)
{
unsigned int old;
hal_virtual_comm_table_t* __chan = __call_vv_CYGNUM_CALL_IF_DEBUG_PROCS();
do {
register int x ;
asm volatile (
"st r1, @-r15 ;\n"
"mov ps, r1 ;\n"
"ldi:8 #0x10, %0 ;\n"
"and r1, %0 ;\n"
"lsr #1, %0 ;\n"
"ld @r15+, r1 ;\n"
"andccr #0xef \n"
: "=r" (x) );
(old) = (x);
} while (0);
while(1)
{
static const char hex[] = "0123456789ABCDEF";
unsigned char csum = 0;
char c1;
int i;
csum += 'O';
for( i = 0; i < __mangler_pos; i++ )
{
char ch = __mangler_line[i];
char h = hex[(ch>>4)&0xF];
char l = hex[ch&0xF];
__call_COMM_IF_PUTC(*__chan,h);
__call_COMM_IF_PUTC(*__chan,l);
csum += h;
csum += l;
}
nak:
if( c1 == '+' ) break;
if( c1 != '-' ) goto nak;
}
__mangler_pos = 0;
do {
register int x = old;
asm volatile (
"CMP #8, %0 ;\n"
"BEQ 0f ;\n"
"ANDCCR #0xEF ;\n"
"BRA 1f;\n" "0:\n"
"ORCCR #0x10 ;\n"
"1:\n" : : "r"(x) );
} while (0);
}
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