https://gcc.gnu.org/g:24949e640307f91a831e0fb699fea85fb9276a09
commit r15-5843-g24949e640307f91a831e0fb699fea85fb9276a09
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date: Sat Nov 30 13:12:13 2024 -0800
gimple-lim: Reuse boolean var when moving PHI
While looking into PR 117859, I noticed that LIM
sometimes would produce `bool_var2 = bool_var1 != 0` instead
of just using bool_var2. This patch allows LIM to reuse bool_var1
in the place where bool_var2 was going to be used.
Bootstrapped and tested on x86_64-linux-gnu.
gcc/ChangeLog:
* tree-ssa-loop-im.cc (move_computations_worker): While moving
phi, reuse the lhs of the conditional if it is a boolean type.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
Diff:
---
gcc/tree-ssa-loop-im.cc | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/gcc/tree-ssa-loop-im.cc b/gcc/tree-ssa-loop-im.cc
index 538a0588d332..0130a809e30f 100644
--- a/gcc/tree-ssa-loop-im.cc
+++ b/gcc/tree-ssa-loop-im.cc
@@ -1304,11 +1304,22 @@ move_computations_worker (basic_block bb)
edges of COND. */
extract_true_false_args_from_phi (dom, stmt, &arg0, &arg1);
gcc_assert (arg0 && arg1);
- t = make_ssa_name (boolean_type_node);
- new_stmt = gimple_build_assign (t, gimple_cond_code (cond),
- gimple_cond_lhs (cond),
- gimple_cond_rhs (cond));
- gsi_insert_on_edge (loop_preheader_edge (level), new_stmt);
+ /* For `bool_val != 0`, reuse bool_val. */
+ if (gimple_cond_code (cond) == NE_EXPR
+ && integer_zerop (gimple_cond_rhs (cond))
+ && types_compatible_p (TREE_TYPE (gimple_cond_lhs (cond)),
+ boolean_type_node))
+ {
+ t = gimple_cond_lhs (cond);
+ }
+ else
+ {
+ t = make_ssa_name (boolean_type_node);
+ new_stmt = gimple_build_assign (t, gimple_cond_code (cond),
+ gimple_cond_lhs (cond),
+ gimple_cond_rhs (cond));
+ gsi_insert_on_edge (loop_preheader_edge (level), new_stmt);
+ }
new_stmt = gimple_build_assign (gimple_phi_result (stmt),
COND_EXPR, t, arg0, arg1);
todo |= TODO_cleanup_cfg;
