[Bug testsuite/108776] new test case c-c++-common/rotate-11.c from r12-9158-ga015ebe382cd6d fails

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108776

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|powerpc64le-linux-gnu       |powerpc64le-linux-gnu
                   |                            |s390x-linux-gnu
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |rguenth at gcc dot gnu.org
   Last reconfirmed|                            |2023-05-11

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Also fails on s390x.

On ppc64le we only have four r<<, baz() and qux() are not handled (why
do we have 6 functions but expect 5 rotates only without checking exactly
which function we expect not to transform?).  On trunk we handle
baz() fine but still do not handle qux().

The IL into forwprop1 is the same so it's likely differences in ranger
behavior triggering here.

branch:

;; Function baz (baz, funcdef_no=2, decl_uid=3331, cgraph_uid=3,
symbol_order=2)

326      range_of_expr(y_11(D)) at stmt _2 = _1 << y_11(D);
327        range_on_entry (y_11(D)) to BB 5
328          range_of_stmt (y_11(D)) at stmt GIMPLE_NOP
   GLOBAL : UPDATE cache for y_11(D) in BB 0 : successors :   : No updates!
             TRUE : (328) range_of_stmt (y_11(D)) unsigned int VARYING

y_11(D) : CACHE: BB 5 DOM query, found unsigned int VARYING at BB0
CACHE: Range for DOM returns : unsigned int VARYING
Filled from dominator! :  unsigned int VARYING
           TRUE : (327) range_on_entry (y_11(D)) unsigned int VARYING
         TRUE : (326) range_of_expr (y_11(D)) unsigned int VARYING
unsigned char baz (unsigned char x, unsigned int y)

trunk:

;; Function baz (baz, funcdef_no=2, decl_uid=3954, cgraph_uid=3,
symbol_order=2)

299      range_of_expr(y_11(D)) at stmt _2 = _1 << y_11(D);
300        range_on_entry (y_11(D)) to BB 5
301          range_of_stmt (y_11(D)) at stmt GIMPLE_NOP
   GLOBAL : UPDATE cache for y_11(D) in BB 0 : successors :   : No updates!
             TRUE : (301) range_of_stmt (y_11(D)) [irange] unsigned int VARYING

y_11(D) : CACHE: BB 5 DOM query for y_11(D), found [irange] unsigned int
VARYING at BB0
302     GORI  outgoing_edge for y_11(D) on edge 2->5
303     GORI    compute op 1 (y_11(D)) at if (y_11(D) > 8)
        GORI      LHS =[irange] _Bool [0, 0] NONZERO 0x0
        GORI      Computes y_11(D) = [irange] unsigned int [0, 8] NONZERO 0xf
intersect Known range : [irange] unsigned int VARYING
        GORI    TRUE : (303) produces  (y_11(D)) [irange] unsigned int [0, 8]
NONZERO 0xf
        GORI  TRUE : (302) outgoing_edge (y_11(D)) [irange] unsigned int [0, 8]
NONZERO 0xf
CACHE: BB 3 DOM query for y_11(D), found [irange] unsigned int VARYING at BB2
304     GORI  outgoing_edge for y_11(D) on edge 2->3
305     GORI    compute op 1 (y_11(D)) at if (y_11(D) > 8)
        GORI      LHS =[irange] _Bool [1, 1]
        GORI      Computes y_11(D) = [irange] unsigned int [9, +INF] intersect
Known range : [irange] unsigned int VARYING
        GORI    TRUE : (305) produces  (y_11(D)) [irange] unsigned int [9,
+INF]
        GORI  TRUE : (304) outgoing_edge (y_11(D)) [irange] unsigned int [9,
+INF]
CACHE: Adjusted edge range for 2->3 : [irange] unsigned int [9, +INF]
CACHE: Range for DOM returns : [irange] unsigned int [9, +INF]
306     GORI  outgoing_edge for y_11(D) on edge 3->5
307     GORI    compute op 1 (y_11(D)) at if (y_11(D) != 16)
        GORI      LHS =[irange] _Bool [0, 0] NONZERO 0x0
        GORI      Computes y_11(D) = [irange] unsigned int [16, 16] NONZERO
0x10 intersect Known range : [irange] unsigned int VARYING
        GORI    TRUE : (307) produces  (y_11(D)) [irange] unsigned int [16, 16]
NONZERO 0x10
        GORI  TRUE : (306) outgoing_edge (y_11(D)) [irange] unsigned int [16,
16] NONZERO 0x10
CACHE: Range for DOM returns : [irange] unsigned int [0, 8][16, 16] NONZERO
0x1f
Filled from dominator! :  [irange] unsigned int [0, 8][16, 16] NONZERO 0x1f
           TRUE : (300) range_on_entry (y_11(D)) [irange] unsigned int [0,
8][16, 16] NONZERO 0x1f
         TRUE : (299) range_of_expr (y_11(D)) [irange] unsigned int [0, 8][16,
16] NONZERO 0x1f
gimple_simplified to _14 = _16;
Removing dead stmt _14 = _16;

unsigned char baz (unsigned char x, unsigned int y)


On x86_64 the IL into forwprop1 is different (logical-op-non-short-circuit):

ppc64le:
  <bb 2> :
  if (y_11(D) > 8)
    goto <bb 3>; [INV]
  else
    goto <bb 5>; [INV]

  <bb 3> :
  if (y_11(D) != 16)
    goto <bb 4>; [INV]
  else
    goto <bb 5>; [INV]

x86_64:
  <bb 2> :
  _1 = y_14(D) > 8;
  _2 = y_14(D) != 16;
  _3 = _1 & _2;
  if (_3 != 0)
    goto <bb 3>; [INV]
  else
    goto <bb 4>; [INV]

Setting --param logical-op-non-short-circuit=1 fixes the testcase for ppc64le
on the branch, I suspect it will be the same for s390x.