gcc/ChangeLog:

PR debug/41343
PR debug/41447
PR debug/41264
PR debug/41338
* tree.def (DEBUG_EXPR_DECL): New.
* rtl.def (DEBUG_EXPR): New.
* gengtype.c (adjust_field_rtx_def): Handle it.
* tree-ssa.c (propagate_var_def_into_debug_stmts): Rename to...
(insert_debug_temp_for_var_def): ... this.  Drop support for
moving.  Take iterator for def stmt; insert debug stmt before it.
Scan early for use count and kind in debug stmts.
(propagate_defs_into_debug_stmts): Rename to...
(insert_debug_temps_for_defs): ... this.  Likewise.
* tree.h (DEBUG_TEMP_UID): New.
* tree.c (next_debug_decl_uid): New.
(make_node_stat): Count debug decls separately.
(copy_node_stat): Likewise.
* cfgexpand.c (expand_debug_expr): Handle DEBUG_EXPR_DECL.
* var-tracking.c (dv_is_decl_p): Recognize it.
(VALUE_RECURSED_INTO): Apply to DEBUG_EXPRs too.
(track_expr_p): Track expanded DEBUG_EXPR_DECLs.
(vt_expand_loc_callback): Expand DEBUG_EXPRs.
(emit_note_insn_var_location): Don't emit notes for DEBUG_EXPR_DECLs.
* cselib.c (rtx_equal_for_cselib_p): Handle DEBUG_EXPR.
(cselib_hash_rtx): Likewise.
(cselib_expand_value_rtx_1): Use callback for DEBUG_EXPR.
* tree-ssa-operands.c (get_expr_operands): Skip DEBUG_EXPR_DECLs in
debug bind stmts.
* emit-rtl.c (verify_rtx_sharing): Handle DEBUG_EXPR and VALUE.
(copy_rtx_if_shared_1, reset_used_flags, set_used_flags): Likewise.
* rtl.c (copy_rtx): Likewise.
(rtx_equal_p_cb, rtx_equal_p): Handle DEBUG_EXPR.
* print-rtl.c (print_rtx): Likewise.
* sched-vis.c (print_value): Likewise.
(print_insn): Handle DEBUG_EXPR_DECL.
* tree-dump.c (dequeue_and_dump): Likewise.
* tree-pretty-print.c (dump_decl_name, dump_generic_node): Likewise.
* gimple-iterator (gsi_replace): Check for same lhs.
(gsi_remove): Insert debug temps.
* tree-ssa-loop-im.c (rewrite_reciprocal): Replace with same lhs.
(move_computations_stmt): Drop explicit propagation into debug stmts.
(rewrite_bittest): Likewise.  Use gsi_remove for propagation.
* tree-ssa-reassoc.c (rewrite_expr_tree, linearize_expr): Likewise.
* tree-ssa-sink.c (statement_sink_location): Likewise.
* tree-ssa-forwprop (forward_propagate_addr_expr): Likewise.
* tree-ssanames.c (release_ssa_name): Adjust for rename.
* tree-flow.h: Likewise.
* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Don't mark
debug temps without values.
(eliminate_unnecessary_stmts): Don't discard just-inserted
debug stmts.
gcc/testsuite/ChangeLog:
PR debug/41343
PR debug/41447
PR debug/41264
PR debug/41338
* gcc.dg/guality/pr41447-1.c: New.
* gcc.dg/debug/pr41264-1.c: New.
* gcc.dg/debug/pr41343-1.c: New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@152681 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 7 insertions, 1 deletions

diff --git a/gcc/gimple-iterator.c b/gcc/gimple-iterator.c
index 66927d67c2c..c3ca0e37501 100644
--- a/gcc/gimple-iterator.c
+++ b/gcc/gimple-iterator.c
@@ -358,7 +358,8 @@ gsi_split_seq_before (gimple_stmt_iterator *i)
 
 /* Replace the statement pointed-to by GSI to STMT.  If UPDATE_EH_INFO
    is true, the exception handling information of the original
-   statement is moved to the new statement.  */
+   statement is moved to the new statement.  Assignments must only be
+   replaced with assignments to the same LHS.  */
 
 void
 gsi_replace (gimple_stmt_iterator *gsi, gimple stmt, bool update_eh_info)
@@ -368,6 +369,9 @@ gsi_replace (gimple_stmt_iterator *gsi, gimple stmt, bool update_eh_info)
   if (stmt == orig_stmt)
     return;
 
+  gcc_assert (!gimple_has_lhs (orig_stmt)
+	      || gimple_get_lhs (orig_stmt) == gimple_get_lhs (stmt));
+
   gimple_set_location (stmt, gimple_location (orig_stmt));
   gimple_set_bb (stmt, gsi_bb (*gsi));
 
@@ -470,6 +474,8 @@ gsi_remove (gimple_stmt_iterator *i, bool remove_permanently)
   gimple_seq_node cur, next, prev;
   gimple stmt = gsi_stmt (*i);
 
+  insert_debug_temps_for_defs (i);
+
   /* Free all the data flow information for STMT.  */
   gimple_set_bb (stmt, NULL);
   delink_stmt_imm_use (stmt);