Hello,
This patch extends the implementation to support instructions with
REG_INC notes.
It addresses the comments from the previous submission:
http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01299.html.
btw, regarding your previous question about the usage of the address
register been auto inc, apparently it can be used as follows:
insn 1) def1 = MEM [ pre_dec (addr) ]
out edges: [1 -(T,2,1)-> 1] [1 -(T,2,0)-> 2]
in edges: [1 -(T,2,1)-> 1] [2 -(T,2,1)-> 1] [2 -(A,0,1)->1]
insn 2) MEM [ addr + 3 ] = def1
out edges: [2 -(T,2,1)-> 1] [2 -(A,0,1)->1]
in edges: [1 -(T,2,0)-> 2]
Reg-moves were not created for the address when testing on ppc.
Tested and bootstrap with patch 1 on ppc64-redhat-linux
enabling SMS on loops with SC 1. On arm-linux-gnueabi bootstrap
c on top of the set of patches that support do-loop pattern
(http://gcc.gnu.org/ml/gcc-patches/2011-07/msg01807.html) which solves
the bootstrap failure on ARM with SMS flags.
OK for mainline?
Thanks,
Revital
* ddg.c (autoinc_var_is_used_p): New function.
(create_ddg_dep_from_intra_loop_link,
add_cross_iteration_register_deps): Call it.
* modulo-sched.c (sms_schedule): Handle instructions with REG_INC.
Index: ddg.c
===================================================================
--- ddg.c (revision 179138)
+++ ddg.c (working copy)
@@ -145,6 +145,23 @@ mem_access_insn_p (rtx insn)
return rtx_mem_access_p (PATTERN (insn));
}
+/* Return true if DEF_INSN contains address been auto-inc or auto-dec
+ which is used in USE_INSN. Otherwise return false. The result is
+ been used to decide whether to remove the edge between def_insn and
+ use_insn when -fmodulo-sched-allow-regmoves is set. */
+static bool
+autoinc_var_is_used_p (rtx def_insn, rtx use_insn)
+{
+ rtx note;
+
+ for (note = REG_NOTES (def_insn); note; note = XEXP (note, 1))
+ if (REG_NOTE_KIND (note) == REG_INC
+ && reg_referenced_p (XEXP (note, 0), PATTERN (use_insn)))
+ return true;
+
+ return false;
+}
+
/* Computes the dependence parameters (latency, distance etc.), creates
a ddg_edge and adds it to the given DDG. */
static void
@@ -173,10 +190,15 @@ create_ddg_dep_from_intra_loop_link (ddg
compensate for that by generating reg-moves based on the life-range
analysis. The anti-deps that will be deleted are the ones which
have true-deps edges in the opposite direction (in other words
- the kernel has only one def of the relevant register). TODO:
- support the removal of all anti-deps edges, i.e. including those
+ the kernel has only one def of the relevant register).
+ If the address that is been auto-inc or auto-dec in DEST_NODE
+ is used in SRC_NODE then do not remove the edge to make sure
+ reg-moves will not be created for this address.
+ TODO: support the removal of all anti-deps edges, i.e. including those
whose register has multiple defs in the loop. */
- if (flag_modulo_sched_allow_regmoves && (t == ANTI_DEP && dt == REG_DEP))
+ if (flag_modulo_sched_allow_regmoves
+ && (t == ANTI_DEP && dt == REG_DEP)
+ && !autoinc_var_is_used_p (dest_node->insn, src_node->insn))
{
rtx set;
@@ -302,10 +324,14 @@ add_cross_iteration_register_deps (ddg_p
gcc_assert (first_def_node);
/* Always create the edge if the use node is a branch in
- order to prevent the creation of reg-moves. */
+ order to prevent the creation of reg-moves.
+ If the address that is been auto-inc or auto-dec in LAST_DEF
+ is used in USE_INSN then do not remove the edge to make sure
+ reg-moves will not be created for that address. */
if (DF_REF_ID (last_def) != DF_REF_ID (first_def)
|| !flag_modulo_sched_allow_regmoves
- || JUMP_P (use_node->insn))
+ || JUMP_P (use_node->insn)
+ || autoinc_var_is_used_p (DF_REF_INSN (last_def), use_insn))
create_ddg_dep_no_link (g, use_node, first_def_node, ANTI_DEP,
REG_DEP, 1);
Index: modulo-sched.c
===================================================================
--- modulo-sched.c (revision 179138)
+++ modulo-sched.c (working copy)
@@ -1266,12 +1271,10 @@ sms_schedule (void)
continue;
}
- /* Don't handle BBs with calls or barriers or auto-increment insns
- (to avoid creating invalid reg-moves for the auto-increment insns),
+ /* Don't handle BBs with calls or barriers
or !single_set with the exception of instructions that include
count_reg---these instructions are part of the control part
that do-loop recognizes.
- ??? Should handle auto-increment insns.
??? Should handle insns defining subregs. */
for (insn = head; insn != NEXT_INSN (tail); insn = NEXT_INSN (insn))
{
@@ -1282,7 +1285,6 @@ sms_schedule (void)
|| (NONDEBUG_INSN_P (insn) && !JUMP_P (insn)
&& !single_set (insn) && GET_CODE (PATTERN (insn)) != USE
&& !reg_mentioned_p (count_reg, insn))
- || (FIND_REG_INC_NOTE (insn, NULL_RTX) != 0)
|| (INSN_P (insn) && (set = single_set (insn))
&& GET_CODE (SET_DEST (set)) == SUBREG))
break;
@@ -1296,8 +1298,6 @@ sms_schedule (void)
fprintf (dump_file, "SMS loop-with-call\n");
else if (BARRIER_P (insn))
fprintf (dump_file, "SMS loop-with-barrier\n");
- else if (FIND_REG_INC_NOTE (insn, NULL_RTX) != 0)
- fprintf (dump_file, "SMS reg inc\n");
else if ((NONDEBUG_INSN_P (insn) && !JUMP_P (insn)
&& !single_set (insn) && GET_CODE (PATTERN (insn)) != USE))
fprintf (dump_file, "SMS loop-with-not-single-set\n");
