Razya Ladelsky wrote:
Hi,
When passing an address of a local variable as the first argument of
'sync_fetch_and_add'
I get an error of unrecognizable insn.
For example, the test below (extracted from
gcc.c-torture/compile/sync-1.c) fails on powerpc.
If however, 'uc' was a global variable, the compilation passed perfectly.
This scenario does not happen for ints, only for chars.
void test_op_ignore (void)
{
unsigned char uc;
(void) __sync_fetch_and_add (&uc, 1);
}
Here's the failure message:
error: unrecognizable insn:
(insn 16 15 17 3 (parallel [
(set (reg:SI 123)
(ior:SI (and:SI (plus:SI (mem/v:QI (reg/f:SI 115
virtual-stack-vars) [-1 S1 A64])
I wonder why you are setting a SImode regester when doing a QImode
fetch_and_add operation. Perhaps the compiler is trying to keep uc in a
register which would not make sense for an atomic memory operation.
Perhaps the insn predicates and/or constraints need to be adjusted so
that the operand is forced into memory.
David Daney
