[Bug tree-optimization/113727] [14 Regression] csmith: differences from nothing to -O1 since r14-4612-g6decda1a35be57

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113727

--- Comment #22 from Richard Biener <rguenth at gcc dot gnu.org> ---
Handling LHS sra_handled_bf_read_p the same as RHS also fixes the issue,
we then detect the partial overlap of the accesses without looking at
grp_partial_lhs.

I wonder if we run into the same issue for REAL/IMAGPART_EXPR on the LHS
when we have both _Complex and component accesses mixed.

So alternative patch:

diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
index f8e71ec48b9..8e9c2e3d343 100644
--- a/gcc/tree-sra.cc
+++ b/gcc/tree-sra.cc
@@ -1161,7 +1161,7 @@ build_access_from_expr_1 (tree expr, gimple *stmt, bool
write)
   bool partial_ref;

   if ((TREE_CODE (expr) == BIT_FIELD_REF
-       && (write || !sra_handled_bf_read_p (expr)))
+       && !sra_handled_bf_read_p (expr))
       || TREE_CODE (expr) == IMAGPART_EXPR
       || TREE_CODE (expr) == REALPART_EXPR)
     {
@@ -3973,7 +3980,7 @@ sra_modify_expr (tree *expr, bool write,
gimple_stmt_iterator *stmt_gsi,
   bool partial_cplx_access = false;

   if (TREE_CODE (*expr) == BIT_FIELD_REF
-      && (write || !sra_handled_bf_read_p (*expr)))
+      && !sra_handled_bf_read_p (*expr))
     {
       bfr = *expr;
       expr = &TREE_OPERAND (*expr, 0);
@@ -4517,7 +4524,7 @@ sra_modify_assign (gimple *stmt, gimple_stmt_iterator
*gsi)
   if (TREE_CODE (rhs) == REALPART_EXPR || TREE_CODE (lhs) == REALPART_EXPR
       || TREE_CODE (rhs) == IMAGPART_EXPR || TREE_CODE (lhs) == IMAGPART_EXPR
       || (TREE_CODE (rhs) == BIT_FIELD_REF && !sra_handled_bf_read_p (rhs))
-      || TREE_CODE (lhs) == BIT_FIELD_REF)
+      || (TREE_CODE (lhs) == BIT_FIELD_REF && !sra_handled_bf_read_p (lhs)))
     {
       modify_this_stmt = sra_modify_expr (gimple_assign_rhs1_ptr (stmt),
                                          false, gsi, gsi);