re PR rtl-optimization/39794 (Miscompile with -O2 -funroll-loops)

re PR rtl-optimization/39794 (Miscompile with -O2 -funroll-loops)

	PR rtl-optimization/39794
	* alias.c (canon_true_dependence): Add x_addr argument.
	* rtl.h (canon_true_dependence): Adjust prototype.
	* cse.c (check_dependence): Adjust canon_true_dependence callers.
	* cselib.c (cselib_invalidate_mem): Likewise.
	* gcse.c (compute_transp): Likewise.
	* dse.c (scan_reads_nospill): Likewise.
	(record_store, check_mem_read_rtx): Likewise.  For non-const-or-frame
	addresses pass base->val_rtx as mem_addr, for const-or-frame addresses
	canon_base_addr of the group, plus optional offset.
	(struct group_info): Rename canon_base_mem to
	canon_base_addr.
	(get_group_info): Set canon_base_addr to canon_rtx of base, not
	canon_rtx of base_mem.

	* gcc.dg/pr39794.c: New test.

From-SVN: r146669