[Bug tree-optimization/95856] New: [11 Regression] error: definition in block 2 follows the use since r11-1582-gcf07eea8429c923b

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95856

            Bug ID: 95856
           Summary: [11 Regression] error: definition in block 2 follows
                    the use since r11-1582-gcf07eea8429c923b
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: rguenth at gcc dot gnu.org
            Blocks: 26163
  Target Milestone: ---

Reduced from blender SPEC2017 benchmark:

$ cat space_graph.i
typedef struct {
  float xmin, xmax;
} rctf;

typedef struct {
  rctf tot;
} View2D;

View2D graph_main_area_draw_v2d;

void get_graph_keyframe_extents();

void
graph_main_area_draw() {
  get_graph_keyframe_extents();
  graph_main_area_draw_v2d.tot.xmin -= 10.0f;
  graph_main_area_draw_v2d.tot.xmax += 10.0f;
}

$ gcc -O3 space_graph.i -c
space_graph.i: In function 'graph_main_area_draw':
space_graph.i:14:1: error: definition in block 2 follows the use
   14 | graph_main_area_draw() {
      | ^~~~~~~~~~~~~~~~~~~~
for SSA_NAME: vect__1.5_9 in statement:
vect__4.7_12 = vect__1.5_9 + vect_cst__10;
during GIMPLE pass: slp
space_graph.i:14:1: internal compiler error: verify_ssa failed
0xfcee12 verify_ssa(bool, bool)
        /home/marxin/Programming/gcc/gcc/tree-ssa.c:1208
0xce0a45 execute_function_todo
        /home/marxin/Programming/gcc/gcc/passes.c:1992
0xce178c do_per_function
        /home/marxin/Programming/gcc/gcc/passes.c:1640
0xce178c execute_todo
        /home/marxin/Programming/gcc/gcc/passes.c:2039
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26163
[Bug 26163] [meta-bug] missed optimization in SPEC (2k17, 2k and 2k6 and 95)