https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128406
Bug ID: 128406
Summary: [16/17 Regression] ICE with abnormal SSA names and
vector constructors
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Keywords: ice-on-valid-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: ktkachov at gcc dot gnu.org
Target Milestone: ---
typedef float v8sf __attribute__ ((vector_size (32)));
extern int rt (void) __attribute__ ((returns_twice));
extern int get (void);
extern void use (float, float, float, float, float, int);
/* x and a0...a3 occur in abnormal PHIs. BB SLP changes the CONSTRUCTOR
into a CONSTRUCTOR of vectors of a0...a3 and of x. A splat of x at the
CONSTRUCTOR would be a use of x after its redefinition. */
void
f (v8sf *out, v8sf v, float x)
{
get ();
float a0 = v[0], a1 = v[1], a2 = v[2], a3 = v[3];
int k = get ();
float b0 = a0, b1 = a1, b2 = a2, b3 = a3;
float y0 = x, y1 = x, y2 = x, y3 = x;
x++;
*out = (v8sf) { b0, b1, b2, b3, y0, y1, y2, y3 };
get ();
rt ();
use (x, a0, a1, a2, a3, k);
}
on x86_64 with -O2 -mavx ICEs:
Unable to coalesce ssa_names 3 and 40 which are marked as MUST COALESCE.
x_3(ab) and x_40(ab)
during RTL pass: expand
<source>: In function 'f':
<source>:11:1: internal compiler error: SSA corruption
11 | f (v8sf *out, v8sf v, float x)
| ^
0x20a13d8 diagnostics::context::diagnostic_impl(rich_location*,
diagnostics::metadata const*, diagnostics::option_id, char const*,
__va_list_tag (*) [1], diagnostics::kind)
???:0
0x209a6cb internal_error(char const*, ...)
???:0
0xfb0dd4 coalesce_ssa_name(_var_map*)
???:0
0xf48ae1 rewrite_out_of_ssa(ssaexpand*)
???:0
