rtl.h (MEM_READONLY_P): Replace RTX_UNCHANGING_P.

	* 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.

From-SVN: r86178

1 files changed, 16 insertions, 46 deletions

diff --git a/gcc/alias.c b/gcc/alias.c
index 7200fff..57bc38d 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -113,7 +113,7 @@ static bool nonoverlapping_component_refs_p (tree, tree);
 static tree decl_for_component_ref (tree);
 static rtx adjust_offset_for_component_ref (tree, rtx);
 static int nonoverlapping_memrefs_p (rtx, rtx);
-static int write_dependence_p (rtx, rtx, int, int);
+static int write_dependence_p (rtx, rtx, int);
 
 static int nonlocal_mentioned_p_1 (rtx *, void *);
 static int nonlocal_mentioned_p (rtx);
@@ -2173,17 +2173,10 @@ true_dependence (rtx mem, enum machine_mode mem_mode, rtx x,
   if (DIFFERENT_ALIAS_SETS_P (x, mem))
     return 0;
 
-  /* Unchanging memory can't conflict with non-unchanging memory.
-     A non-unchanging read can conflict with a non-unchanging write.
-     An unchanging read can conflict with an unchanging write since
-     there may be a single store to this address to initialize it.
-     Note that an unchanging store can conflict with a non-unchanging read
-     since we have to make conservative assumptions when we have a
-     record with readonly fields and we are copying the whole thing.
-     Just fall through to the code below to resolve potential conflicts.
-     This won't handle all cases optimally, but the possible performance
-     loss should be negligible.  */
-  if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem))
+  /* Read-only memory is by definition never modified, and therefore can't
+     conflict with anything.  We don't expect to find read-only set on MEM,
+     but stupid user tricks can produce them, so don't abort.  */
+  if (MEM_READONLY_P (x))
     return 0;
 
   if (nonoverlapping_memrefs_p (mem, x))
@@ -2253,14 +2246,10 @@ canon_true_dependence (rtx mem, enum machine_mode mem_mode, rtx mem_addr,
   if (DIFFERENT_ALIAS_SETS_P (x, mem))
     return 0;
 
-  /* If X is an unchanging read, then it can't possibly conflict with any
-     non-unchanging store.  It may conflict with an unchanging write though,
-     because there may be a single store to this address to initialize it.
-     Just fall through to the code below to resolve the case where we have
-     both an unchanging read and an unchanging write.  This won't handle all
-     cases optimally, but the possible performance loss should be
-     negligible.  */
-  if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem))
+  /* Read-only memory is by definition never modified, and therefore can't
+     conflict with anything.  We don't expect to find read-only set on MEM,
+     but stupid user tricks can produce them, so don't abort.  */
+  if (MEM_READONLY_P (x))
     return 0;
 
   if (nonoverlapping_memrefs_p (x, mem))
@@ -2294,11 +2283,10 @@ canon_true_dependence (rtx mem, enum machine_mode mem_mode, rtx mem_addr,
 }
 
 /* Returns nonzero if a write to X might alias a previous read from
-   (or, if WRITEP is nonzero, a write to) MEM.  If CONSTP is nonzero,
-   honor the RTX_UNCHANGING_P flags on X and MEM.  */
+   (or, if WRITEP is nonzero, a write to) MEM.  */
 
 static int
-write_dependence_p (rtx mem, rtx x, int writep, int constp)
+write_dependence_p (rtx mem, rtx x, int writep)
 {
   rtx x_addr, mem_addr;
   rtx fixed_scalar;
@@ -2317,18 +2305,9 @@ write_dependence_p (rtx mem, rtx x, int writep, int constp)
   if (DIFFERENT_ALIAS_SETS_P (x, mem))
     return 0;
 
-  if (constp)
-    {
-      /* Unchanging memory can't conflict with non-unchanging memory.  */
-      if (RTX_UNCHANGING_P (x) != RTX_UNCHANGING_P (mem))
-	return 0;
-
-      /* If MEM is an unchanging read, then it can't possibly conflict with
-	 the store to X, because there is at most one store to MEM, and it
-	 must have occurred somewhere before MEM.  */
-      if (! writep && RTX_UNCHANGING_P (mem))
-	return 0;
-    }
+  /* A read from read-only memory can't conflict with read-write memory.  */
+  if (!writep && MEM_READONLY_P (mem))
+    return 0;
 
   if (nonoverlapping_memrefs_p (x, mem))
     return 0;
@@ -2369,7 +2348,7 @@ write_dependence_p (rtx mem, rtx x, int writep, int constp)
 int
 anti_dependence (rtx mem, rtx x)
 {
-  return write_dependence_p (mem, x, /*writep=*/0, /*constp*/1);
+  return write_dependence_p (mem, x, /*writep=*/0);
 }
 
 /* Output dependence: X is written after store in MEM takes place.  */
@@ -2377,16 +2356,7 @@ anti_dependence (rtx mem, rtx x)
 int
 output_dependence (rtx mem, rtx x)
 {
-  return write_dependence_p (mem, x, /*writep=*/1, /*constp*/1);
-}
-
-/* Unchanging anti dependence: Like anti_dependence but ignores
-   the UNCHANGING_RTX_P property on const variable references.  */
-
-int
-unchanging_anti_dependence (rtx mem, rtx x)
-{
-  return write_dependence_p (mem, x, /*writep=*/0, /*constp*/0);
+  return write_dependence_p (mem, x, /*writep=*/1);
 }
 
 /* A subroutine of nonlocal_mentioned_p, returns 1 if *LOC mentions