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.

From-SVN: r152681