blob: bc637302dfae5a6223397ef6d3a5fadeb8564b2e [file] [log] [blame]
/* Check that all more-or-less trivially fillable delayed-branch-slots
are filled. */
/* { dg-do compile } */
/* { dg-options "-O2" } */
/* { dg-final { scan-assembler-times "\tnop|addq 8,|subq 8," 2 } } */
/* The reason for the weird variant of scan-assembler-not "\tnop" is that we
used to have an unused DWunion temp on stack in xlshrdi3 and delay-slots for
the conditional jumps filled by the addq 8/subq setting up that, but with a
MAX_FIXED_MODE_SIZE no longer 32, but the default 64, that stack-frame is
eliminated, but we no longer have eligible insns to fill the delay-slots.
Not wanting to tweak the code in the test-case, this is second best: allowing
two nops -or- an addq 8 + subq 8 assuming code generation is otherwise
reasonably sane. */
void *f(void **p)
/* Supposedly the memory read finds its way into the "ret"
delay-slot. */
return *p;
#if 0
/* Until the negative effects of g:897a73086b2 a.k.a. r10-6395
a.k.a. "One more fix for PR 91333 - suboptimal register allocation
for inline asm", which appears to have caused a "nop" (unfilled
delay-slot) to appear for this function for CRIS-decc0rated (but not
CRIS-cc0) and increasing one execution-path by one instruction (and
the size of the whole function), it's left out. It was but a mere
attempt to expose the flaw better noticed with xlshrdi3. It exposes
a real issue, just less important. FIXME: extract to separate test. */
int g(int *x, int *y, char *v, int n)
int z = *x;
int w = *v + 31;
/* Two branch and two return slots, all filled. */
if (z != 23 && z != n+1)
return *x+*y+24+w;
return *y+24+w;
/* No problem with the two examples above, but with a more involved
example, the epilogue contents matter (the condition-code register
clobber was mistaken for a register that needed to be alive). */
struct DWstruct {int low, high;};
typedef unsigned long long DItype;
typedef unsigned int USItype;
typedef union
struct DWstruct s;
DItype ll;
} DWunion;
unsigned long long
xlshrdi3 (DItype u, unsigned int b)
if (b == 0)
return u;
const DWunion uu = {.ll = u};
const int bm = (4 * 8) - b;
DWunion w;
if (bm <= 0)
w.s.high = 0;
w.s.low = (USItype) uu.s.high >> -bm;
const USItype carries = (USItype) uu.s.high << bm;
w.s.high = (USItype) uu.s.high >> b;
w.s.low = ((USItype) uu.s.low >> b) | carries;
return w.ll;