https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104322
Bug ID: 104322
Summary: Dead code in gcc/tree-vect-loop.cc
Product: gcc
Version: 12.0
Status: UNCONFIRMED
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
Target Milestone: ---
I noticed the following dead code:
gcc/tree-vect-loop.cc:6643
if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def)
stmt_info = vect_stmt_to_vectorize (STMT_VINFO_REDUC_DEF (stmt_info));
else
{
gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info)
== vect_double_reduction_def);
use_operand_p use_p;
gimple *use_stmt;
bool res = single_imm_use (gimple_phi_result (stmt_info->stmt),
&use_p, &use_stmt);
gcc_assert (res);
phi_info = loop_vinfo->lookup_stmt (use_stmt);
stmt_info = vect_stmt_to_vectorize (STMT_VINFO_REDUC_DEF (phi_info));
}
/* PHIs should not participate in patterns. */
gcc_assert (!STMT_VINFO_RELATED_STMT (phi_info));
gphi *reduc_def_phi = as_a <gphi *> (phi_info->stmt);
/* Verify following REDUC_IDX from the latch def leads us back to the PHI
and compute the reduction chain length. Discover the real
reduction operation stmt on the way (stmt_info and slp_for_stmt_info). */
tree reduc_def
= PHI_ARG_DEF_FROM_EDGE (reduc_def_phi,
loop_latch_edge
(gimple_bb (reduc_def_phi)->loop_father));
unsigned reduc_chain_length = 0;
bool only_slp_reduc_chain = true;
stmt_info = NULL;
As seen the 2 assignments to stmt_info are dead.
