On Tue, May 10, 2016 at 10:12 PM, Eric Botcazou <ebotca...@adacore.com> wrote: > Hi, > > this patch is aimed at cleaning up the mess with the RTL libfunc machinery. > > On the one hand you have comments like these in the RTL expander: > > /* It is incorrect to use the libcall calling conventions to call > memcpy in this context. This could be a user call to memcpy and > the user may wish to examine the return value from memcpy. For > targets where libcalls and normal calls have different conventions > for returning pointers, we could end up generating incorrect code. */ > > /* It is incorrect to use the libcall calling conventions to call > memset in this context. This could be a user call to memset and > the user may wish to examine the return value from memset. For > targets where libcalls and normal calls have different conventions > for returning pointers, we could end up generating incorrect code. */ > > and on the other hand you have at the end of expand_builtin_memcmp: > > emit_library_call_value (memcmp_libfunc, result, LCT_PURE, > TYPE_MODE (integer_type_node), 3, > XEXP (arg1_rtx, 0), Pmode, > XEXP (arg2_rtx, 0), Pmode, > convert_to_mode (TYPE_MODE (sizetype), arg3_rtx, > TYPE_UNSIGNED (sizetype)), > TYPE_MODE (sizetype)); > > so the RTL expander is not allowed to call memcpy & memset libfuncs on its own > but it is for __builtin_memcmp, which is rather inconsistent. > > So the patch eliminates all the RTL libfuncs and replaces them by calls to the > corresponding builtins, except for 3 of them: > - synchronize_libfunc, which is used by the ARM and MIPS back-ends, > - unwind_sjlj_register_libfunc, which is used by the SJLJ machinery, > - unwind_sjlj_unregister_libfunc, likewise. > > abort_libfunc and memcmp_libfunc are set by VMS to something else than the > default but this looks like an optimization and can presumably be dropped. > > Bootstrapped/regtested on x86-64/Linux and PowerPC/Linux, OK for mainline?
The middle-end parts are ok, I'm leaving backend parts for their maintainers to comment but those parts are ok as well if they do not comment within a reasonable amount of time. Did you check the internals manual if it needs adjustment? Thanks, Richard. > > 2016-05-10 Eric Botcazou <ebotca...@adacore.com> > > * builtins.c (expand_builtin_memcmp): Do not emit the call here. > (expand_builtin_trap): Emit a regular call. > (set_builtin_user_assembler_name): Remove obsolete cases. > * dse.c (scan_insn): Adjust. > * except.c: Include calls.h. > (sjlj_emit_function_enter): If DONT_USE_BUILTIN_SETJMP is defined, > emit a regular call to setjmp. > * expr.c (emit_block_move_hints): Call emit_block_copy_via_libcall. > (block_move_libcall_safe_for_call_parm): Use memcpy builtin. > (emit_block_move_via_libcall): Delete. > (block_move_fn): Delete. > (init_block_move_fn): Likewise. > (emit_block_move_libcall_fn): Likewise. > (emit_block_op_via_libcall): New function. > (set_storage_via_libcall): Tidy up and use memset builtin. > (block_clear_fn): Delete. > (init_block_clear_fn): Likewise. > (clear_storage_libcall_fn): Likewise. > (expand_assignment): Call emit_block_move_via_libcall. > Do not include gt-expr.h. > * expr.h (emit_block_op_via_libcall): Declare. > (emit_block_copy_via_libcall): New inline function. > (emit_block_move_via_libcall): Likewise. > (emit_block_comp_via_libcall): Likewise. > (block_clear_fn): Delete. > (init_block_move_fn): Likewise. > (init_block_clear_fn): Likewise. > (emit_block_move_via_libcall): Likewise. > (set_storage_via_libcall): Add default parameter value. > * libfuncs.h (enum libfunc_index): Remove obsolete values. > (abort_libfunc): Delete. > (memcpy_libfunc): Likewise. > (memmove_libfunc): Likewise. > (memcmp_libfunc): Likewise. > (memset_libfunc): Likewise. > (setbits_libfunc): Likewise. > (setjmp_libfunc): Likewise. > (longjmp_libfunc): Likewise. > (profile_function_entry_libfunc): Likewise. > (profile_function_exit_libfunc): Likewise. > (gcov_flush_libfunc): Likewise. > * optabs-libfuncs.c (build_libfunc_function): Set DECL_ARTIFICIAL > and DECL_VISIBILITY on the declaration. > (init_optabs): Do not initialize obsolete libfuncs. > * optabs.c (prepare_cmp_insn): Call emit_block_comp_via_libcall. > * tree-core.h (ECF_RET1): Define. > (ECF_TM_PURE): Adjust. > (ECF_TM_BUILTIN): Likewise. > * tree.c (set_call_expr_flags): Deal with ECF_RET1. > (build_common_builtin_nodes): Initialize abort builtin. > Add ECF_RET1 on memcpy, memmove and memset builtins. > Pass final flags for alloca and alloca_with_align builtins. > * config/alpha/alpha.c (alpha_init_libfuncs): Do not initialize > obsolete builtins. > * config/ia64/ia64.c (ia64_vms_init_libfuncs): Likewise. > * config/i386/i386.c (ix86_expand_set_or_movmem): Adjust call to > set_storage_via_libcall and call emit_block_copy_via_libcall. > > -- > Eric Botcazou
