https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71632
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
In any case, this looks to me like expansion or TER bug.
The problem in this case is that expand_cond_expr_using_cmove
expands the tree arguments:
op00 = expand_normal (gimple_assign_rhs1 (srcstmt));
op01 = expand_normal (gimple_assign_rhs2 (srcstmt));
and then calls emit_conditional_move, which fails, thus we throw it all away,
and the caller of expand_cond_expr_using_cmove then calls jumpifnot, which
expands those again. I bet this isn't the only spot in the expander that does
it similarly. The problem is that with very deep TER trees this has
prohibitive compile time/memory complexity.
So, either we need to fix all the places in the expander that might try to
expand the same tree argument multiple times, or we need to tweak TER, so that
it e.g. counts number of leafs in a TER tree and/or their maximum depth and
artificially disables TER of certain SSA_NAMEs so that one expand_normal has
always reasonably sized TER trees to expand, not something unbounded.
void
foo (double d, double *p, double *q)
{
int i;
for (i = 0; i < 64; i++)
{
double t1 = d > p[0] ? 1.0 : 0.0;
double t2 = t1 > p[1] ? 1.0 : 0.0;
double t3 = t2 > p[2] ? 1.0 : 0.0;
double t4 = t3 > p[3] ? 1.0 : 0.0;
double t5 = t4 > p[4] ? 1.0 : 0.0;
double t6 = t5 > p[5] ? 1.0 : 0.0;
double t7 = t6 > p[6] ? 1.0 : 0.0;
double t8 = t7 > p[7] ? 1.0 : 0.0;
double t9 = t8 > p[8] ? 1.0 : 0.0;
double t10 = t9 > p[9] ? 1.0 : 0.0;
double t11 = t10 > p[10] ? 1.0 : 0.0;
double t12 = t11 > p[11] ? 1.0 : 0.0;
double t13 = t12 > p[12] ? 1.0 : 0.0;
double t14 = t13 > p[13] ? 1.0 : 0.0;
double t15 = t14 > p[14] ? 1.0 : 0.0;
double t16 = t15 > p[15] ? 1.0 : 0.0;
double t17 = t16 > p[16] ? 1.0 : 0.0;
double t18 = t17 > p[17] ? 1.0 : 0.0;
double t19 = t18 > p[18] ? 1.0 : 0.0;
double t20 = t19 > p[19] ? 1.0 : 0.0;
double t21 = t20 > p[20] ? 1.0 : 0.0;
double t22 = t21 > p[21] ? 1.0 : 0.0;
double t23 = t22 > p[22] ? 1.0 : 0.0;
double t24 = t23 > p[23] ? 1.0 : 0.0;
double t25 = t24 > p[24] ? 1.0 : 0.0;
double t26 = t25 > p[25] ? 1.0 : 0.0;
double t27 = t26 > p[26] ? 1.0 : 0.0;
double t28 = t27 > p[27] ? 1.0 : 0.0;
double t29 = t28 > p[28] ? 1.0 : 0.0;
double t30 = t29 > p[29] ? 1.0 : 0.0;
double t31 = t30 > p[30] ? 1.0 : 0.0;
double t32 = t31 > p[31] ? 1.0 : 0.0;
double t33 = t32 > p[32] ? 1.0 : 0.0;
double t34 = t33 > p[33] ? 1.0 : 0.0;
double t35 = t34 > p[34] ? 1.0 : 0.0;
double t36 = t35 > p[35] ? 1.0 : 0.0;
double t37 = t36 > p[36] ? 1.0 : 0.0;
double t38 = t37 > p[37] ? 1.0 : 0.0;
double t39 = t38 > p[38] ? 1.0 : 0.0;
*q = t39;
p += 39;
q++;
}
}
