[Bug target/20331] [3.4/4.0/4.1 Regression] Wrong code generation for the argument of the pure function in PIC

Tue Mar 8 21:58:00 GMT 2005

------- Additional Comments From amylaar at gcc dot gnu dot org  2005-03-08 21:58 -------
(In reply to comment #1)
> I've traced what's going on:
>   http://gcc.gnu.org/ml/gcc-patches/2005-03/msg00525.html
> It includes a patch for comment.
> 

The sh64 port is partcularily exposed in emit_libcall_block because it uses
paradoxical subregs to set up the offset part of the PIC address, but I
think your patch makes sense.  Except that this is only the tip of the iceberg.
The problem was introduced in a maga-patch to remove RTX_UNCHANGING_P; there
are a number of other places that need to be fixed up similarily.

2004-08-18  Richard Henderson  <rth@redhat.com>

        * rtl.h (MEM_READONLY_P): Replace RTX_UNCHANGING_P.
        * alias.c (true_dependence): Update to match new semantics.
        (canon_true_dependence, write_dependence_p): Likewise.
        (anti_dependence, output_dependence): Update write_dependence_p args.
        (unchanging_anti_dependence): Remove.
        * calls.c (purge_mem_unchanging_flag): Remove.
        (fixup_tail_calls): Don't call it.
        (expand_call): Don't add unchanging memory to function usage.
        * expr.c (emit_block_move_via_libcall): Likewise.
        (clear_storage_via_libcall): Don't clobber RTX_UNCHANGING_P mems.
        (get_subtarget): Don't use RTX_UNCHANGING_P.
        (expand_assignment, store_constructor, expand_expr_real_1): Likewise.
        (do_tablejump): Set MEM_READONLY_P, not RTX_UNCHANGING_P.
        * combine.c (get_last_value_validate): Use MEM_READONLY_P.
        * cse.c (insert): Don't use RTX_UNCHANGING_P.
        (cse_insn, canon_hash): Use MEM_READONLY_P.
        * emit-rtl.c (set_mem_attributes_minus_bitpos): Use MEM_READONLY_P
        instead of RTX_UNCHANGING_P.
        * explow.c (maybe_set_unchanging): Remove.
        * expr.h (maybe_set_unchanging): Remove.
        * flow.c (insn_dead_p, mark_used_regs): Use anti_dependence.
        * function.c (assign_stack_temp_for_type): Don't use RTX_UNCHANGING_P.
        (assign_parm_setup_reg, expand_function_start): Likewise.
        * integrate.c (copy_rtx_and_substitute): Likewise.
        * ra-rewrite.c (emit_colors): Likewise.
        * regmove.c (copy_src_to_dest, regmove_optimize): Likewise.
        (fixup_match_1): Likewise.
        * reload1.c (reload, alter_reg): Likewise.
        * local-alloc.c (validate_equiv_mem): Check MEM_READONLY_P,
        not RTX_UNCHANGING_P.
        (equiv_init_varies_p): Likewise.
        * loop-invariant.c (check_maybe_invariant): Likewise.
        * resource.c (mark_referenced_resources, mark_set_resources): Likewise.
        * loop.c (note_addr_stored): Likewise.
        (prescan_loop): Likewise. Don't check function usage for clobbered
        unchanging memory.
        * rtlanal.c (rtx_unstable_p): Check MEM_READONLY_P,
        not RTX_UNCHANGING_P.
        (rtx_varies_p, modified_between_p, modified_in_p): Likewise.
        * varasm.c (force_const_mem): Likewise.
        * stmt.c (expand_decl): Don't set RTX_UNCHANGING_P.
        * web.c (entry_register): Likewise.
        * tree-gimple.h (get_base_address): Move decl ...
        * tree.h: ... here.
        * doc/rtl.texi (MEM_READONLY_P): Replace RTX_UNCHANGING_P.

        * config/alpha/alpha.c (alpha_set_memflags_1): Rewrite to be
        called via for_each_rtx.  Copy MEM_SCALAR_P, MEM_NOTRAP_P too.
        (alpha_set_memflags): Update to match.

        * config/darwin.c (machopic_indirect_data_reference): Set
        MEM_READONLY_P instead of RTX_UNCHANGING_P.
        (machopic_indirect_call_target): Likewise.
        (machopic_legitimize_pic_address): Likewise.
        * config/arm/arm.c (legitimize_pic_address, arm_gen_load_multiple,
        arm_gen_store_multiple, arm_gen_movmemqi): Likewise.
        * config/arm/arm.md (load_multiple, store_multiple): Likewise.
        * config/frv/frv.md (symGOT2reg): Likewise.
        * config/i386/i386.c (legitimize_pic_address,
        legitimize_tls_address, ix86_split_to_parts): Likewise.
        * config/ia64/ia64.c (ia64_expand_tls_address): Likewise.
        * config/ia64/ia64.md (load_fptr): Likewise.
        * config/m32r/m32r.c (m32r_legitimize_pic_address): Likewise.
        * config/m68k/m68k.c (legitimize_pic_address): Likewise.
        * config/mcore/mcore.c (block_move_sequence): Likewise.
        * config/mn10300/mn10300.md (symGOT2reg): Likewise.
        * config/pa/pa.c (legitimize_pic_address): Likewise.
        * config/rs6000/rs6000.c (rs6000_legitimize_tls_address): Likewise.
        (rs6000_emit_move): Likewise.
        * config/s390/s390.c (legitimize_pic_address): Likewise.
        (legitimize_tls_address): Likewise.
        * config/s390/s390.md (casesi): Likewise.
        * config/sh/sh.c (prepare_move_operands, sh_reorg): Likewise.
        * config/sh/sh.md (symGOT2reg): Likewise.
        * config/sparc/sparc.c (legitimize_pic_address): Likewise.
        * config/v850/v850.md (casesi): Likewise.

        * config/ia64/ia64.c (gen_thread_pointer): Don't set RTX_UNCHANGING_P.
        * config/iq2000/iq2000.c (save_restore_insns): Likewise.
        * config/mips/mips.c (mips_restore_gp): Likewise.
        (mips_save_restore_reg, mips16_gp_pseudo_reg): Likewise.
        * config/sh/sh.c (sh_reorg): Likewise.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amylaar at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-03-08 21:58:34
               date|                            |

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20331