#1930 gcc-torture-execute-pr20466-1 fails

[Philipp Klaus Krause]

When removing the preprocessor guard, the gcc-torture-execute-pr20466-1 regression test fails for all ports in revision #7290.

Philipp

[Sergey Belyashov]

I have added more checks to the test:

int
f (int **ipp, int *i1p, int *i2p, int **i3, int **i4)
{
  **ipp = *i1p;
  *ipp = i2p;
  *i3 = *i4;
  **ipp = 99;
  return 3;
}

void
testTortureExecute (void)
{
  int i = 42, i1 = 66, i2 = 1, i3 = -1, i4 = 55;
  int *ip = &i;
  int *i3p = &i3;
  int *i4p = &i4;
#if !(defined(__SDCC_pic14) && !defined(__SDCC_PIC14_ENHANCED)) // Pseudo-stack size limit
  f (&ip, &i1, &i2, &i3p, &i4p);
  ASSERT(i == 66);
  ASSERT(ip == &i2);
  ASSERT(i2 == 99);
  ASSERT(i3 == -1);
  ASSERT(i3p == i4p);
  ASSERT(i4 == 55);
  if (i != 66 || ip != &i2 || i2 != 99 || i3 != -1 || i3p != i4p || i4 != 55)
    ASSERT (0);
  return;
#endif
}

Result: FAIL: "Assertion failed" on i2 == 99
Next I look into generated asm file:

...
;gen/ucz80/gcc-torture-execute-pr20466-1/gcc-torture-execute-pr20466-1.c:18: *i3 = *i4;
;       genAssign
;       AOP_STK for
;fetchPairLong
        ld      c, 10 (ix)
        ld      b, 11 (ix)
;       genAssign
;       AOP_STK for
;fetchPairLong
        ld      l, 12 (ix)
        ld      h, 13 (ix)
;       genPointerGet
;fetchPairLong
;       _moveFrom_tpair_()
        ld      e, (hl)
        inc     hl
;       _moveFrom_tpair_()
        ld      d, (hl)
;       genAssign (pointer)
;       isBitvar = 0
;fetchPairLong
        ld      a, e
        ld      (bc), a
        inc     bc
        ld      a, d
        ld      (bc), a
;gen/ucz80/gcc-torture-execute-pr20466-1/gcc-torture-execute-pr20466-1.c:20: return 3;
...

So **ipp = 99; was eliminated out. Why?

[Sergey Belyashov]

Continue investigation...
Operation is marked dead by CSE and GCSE (any one) optimizations. It is eliminated on line SDCCopt.c:3207 by killDeadCode().

More deep investigation should do cse hacker :-)

[Erik Petrich]

Fixed in [r13788]