/* { dg-options "-O2 -m32 -march=i386" }
/* { dg-do compile } */
typedef struct
{
void *A;
void *B;
void *C;
unsigned long D;
} S;
void
foo (S *x)
{
unsigned long long *c = x->C;
unsigned long long *a = x->A;
unsigned long long *b = x->B;
unsigned long d = x->D;
for (; d >= 2; d -= 2)
{
asm volatile ("" : "=m" (*c) : "m" (*a), "m" (*b) : "eax", "ecx", "edx",
"cc");
c++;
b++;
a++;
}
if (d > 0)
asm volatile ("" : "=m" (*c) : "m" (*a), "m" (*b) : "eax", "ecx", "edx",
"cc");
}
(distilled from the GIMP) ICEs on HEAD/4.1 when not -fomit-frame-pointer.
As the pattern clobbers 3 registers out of 6 available ones, I think it should
be theoretically reloadable (just use (%ebx) for one memory, (%esi) for another
one and (%edi) for yet another one.
But after tree-ssa we end up with:
__asm__ __volatile__("":"=m" *(c + D.1386):"m" *(a + D.1386), "m" *(b +
D.1386):"cc", "edx", "ecx", "eax");
which is one register too much if a, b, c and D.1386 need each assigned one
reg.
Reload should try harder in that case though, and just create temporaries, say
%ebx = (c + D.1386)
%esi = (a + D.1386)
%edi = (b + D.1386).
--
Summary: reload bailing out even when some regs are still
available
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jakub at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25221
