On Mon, Jun 12, 2017 at 6:02 PM, Bin Cheng <bin.ch...@arm.com> wrote:
> Hi,
> I was asked by upstream to split the loop distribution patch into small ones.
> It is hard because data structure and algorithm are closely coupled together.
> Anyway, this is the patch series with smaller patches. Basically I tried to
> separate data structure and bug-fix changes apart with one as the main patch.
> Note I only made necessary code refactoring in order to separate patch, apart
> from that, there is no change against the last version.
>
> This is the first patch introducing new internal function IFN_LOOP_DIST_ALIAS.
> GCC will distribute loops under condition of this function call.
>
> Bootstrap and test on x86_64 and AArch64. Is it OK?
Hi,
I need to update this patch fixing an issue in
vect_loop_dist_alias_call. The previous patch fails to find some
IFN_LOOP_DIST_ALIAS calls.
Bootstrap and test in series. Is it OK?
Thanks,
bin
>
> Thanks,
> bin
> 2017-06-07 Bin Cheng <bin.ch...@arm.com>
>
> * cfgloop.h (struct loop): New field ldist_alias_id.
> * cfgloopmanip.c (lv_adjust_loop_entry_edge): Comment change.
> * internal-fn.c (expand_LOOP_DIST_ALIAS): New function.
> * internal-fn.def (LOOP_DIST_ALIAS): New.
> * tree-vectorizer.c (vect_loop_dist_alias_call): New function.
> (fold_loop_dist_alias_call): New function.
> (vectorize_loops): Fold IFN_LOOP_DIST_ALIAS call depending on
> successful vectorization or not.
From ab8334c5f109c593610df3efcf1aa5a2edcf6be9 Mon Sep 17 00:00:00 2001
From: Bin Cheng <binch...@e108451-lin.cambridge.arm.com>
Date: Wed, 7 Jun 2017 13:04:03 +0100
Subject: [PATCH 01/13] ifn_loop_dist_alias-20170608.txt
---
gcc/cfgloop.h | 9 ++++++
gcc/cfgloopmanip.c | 3 +-
gcc/internal-fn.c | 8 ++++++
gcc/internal-fn.def | 1 +
gcc/tree-vectorizer.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++-
5 files changed, 98 insertions(+), 2 deletions(-)
diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
index a8bec1d..be4187a 100644
--- a/gcc/cfgloop.h
+++ b/gcc/cfgloop.h
@@ -225,6 +225,15 @@ struct GTY ((chain_next ("%h.next"))) loop {
builtins. */
tree simduid;
+ /* For loops generated by distribution with runtime alias checks, this
+ is a unique identifier of the original distributed loop. Generally
+ it is the number of the original loop. IFN_LOOP_DIST_ALIAS builtin
+ uses this id as its first argument. Give a loop with an id, we can
+ look upward in dominance tree for the corresponding IFN_LOOP_DIST_ALIAS
+ buildin. Note this id has no meanling after IFN_LOOP_DIST_ALIAS is
+ folded and eliminated. */
+ int ldist_alias_id;
+
/* Upper bound on number of iterations of a loop. */
struct nb_iter_bound *bounds;
diff --git a/gcc/cfgloopmanip.c b/gcc/cfgloopmanip.c
index d764ab9..adb2f65 100644
--- a/gcc/cfgloopmanip.c
+++ b/gcc/cfgloopmanip.c
@@ -1653,7 +1653,8 @@ force_single_succ_latches (void)
THEN_PROB is the probability of then branch of the condition.
ELSE_PROB is the probability of else branch. Note that they may be both
- REG_BR_PROB_BASE when condition is IFN_LOOP_VECTORIZED. */
+ REG_BR_PROB_BASE when condition is IFN_LOOP_VECTORIZED or
+ IFN_LOOP_DIST_ALIAS. */
static basic_block
lv_adjust_loop_entry_edge (basic_block first_head, basic_block second_head,
diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c
index 75fe027..96e40cb 100644
--- a/gcc/internal-fn.c
+++ b/gcc/internal-fn.c
@@ -2250,6 +2250,14 @@ expand_LOOP_VECTORIZED (internal_fn, gcall *)
gcc_unreachable ();
}
+/* This should get folded in tree-vectorizer.c. */
+
+static void
+expand_LOOP_DIST_ALIAS (internal_fn, gcall *)
+{
+ gcc_unreachable ();
+}
+
/* Expand MASK_LOAD call STMT using optab OPTAB. */
static void
diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def
index e162d81..79c19fb 100644
--- a/gcc/internal-fn.def
+++ b/gcc/internal-fn.def
@@ -158,6 +158,7 @@ DEF_INTERNAL_FN (GOMP_SIMD_LAST_LANE, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)
DEF_INTERNAL_FN (GOMP_SIMD_ORDERED_START, ECF_LEAF | ECF_NOTHROW, NULL)
DEF_INTERNAL_FN (GOMP_SIMD_ORDERED_END, ECF_LEAF | ECF_NOTHROW, NULL)
DEF_INTERNAL_FN (LOOP_VECTORIZED, ECF_NOVOPS | ECF_LEAF | ECF_NOTHROW, NULL)
+DEF_INTERNAL_FN (LOOP_DIST_ALIAS, ECF_NOVOPS | ECF_LEAF | ECF_NOTHROW, NULL)
DEF_INTERNAL_FN (ANNOTATE, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)
DEF_INTERNAL_FN (UBSAN_NULL, ECF_LEAF | ECF_NOTHROW, ".R.")
DEF_INTERNAL_FN (UBSAN_BOUNDS, ECF_LEAF | ECF_NOTHROW, NULL)
diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index 1bef2e4..05e9f84 100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -469,6 +469,67 @@ fold_loop_vectorized_call (gimple *g, tree value)
}
}
+/* If LOOP has been versioned during loop distribution, return the internal
+ call guarding it. */
+
+static gimple *
+vect_loop_dist_alias_call (struct loop *loop)
+{
+ gimple_stmt_iterator gsi;
+ gimple *g;
+ basic_block bb = loop_preheader_edge (loop)->src;
+ basic_block entry = ENTRY_BLOCK_PTR_FOR_FN (cfun);
+ struct loop *outer_loop = bb->loop_father;
+
+ /* Look upward in dominance tree. */
+ for (; bb != entry && flow_bb_inside_loop_p (outer_loop, bb);
+ bb = get_immediate_dominator (CDI_DOMINATORS, bb))
+ {
+ if (bb->loop_father != outer_loop)
+ continue;
+
+ g = last_stmt (bb);
+ if (g == NULL || gimple_code (g) != GIMPLE_COND)
+ continue;
+
+ gsi = gsi_for_stmt (g);
+ gsi_prev (&gsi);
+ if (gsi_end_p (gsi))
+ continue;
+
+ g = gsi_stmt (gsi);
+ /* The guarding internal function call must have the same distribution
+ alias id. */
+ if (gimple_call_internal_p (g, IFN_LOOP_DIST_ALIAS)
+ && (tree_to_shwi (gimple_call_arg (g, 0)) == loop->ldist_alias_id))
+ return g;
+ }
+ return NULL;
+}
+
+/* Fold LOOP_DIST_ALIAS internal call stmt according to KEEP_P and update
+ any immediate uses of it's LHS. Stmt is folded to its second argument
+ if KEEP_P is true, otherwise to boolean_false_node. */
+
+static void
+fold_loop_dist_alias_call (gimple *g, bool keep_p)
+{
+ tree lhs = gimple_call_lhs (g);
+ use_operand_p use_p;
+ imm_use_iterator iter;
+ gimple *use_stmt;
+ gimple_stmt_iterator gsi = gsi_for_stmt (g);
+ tree folded_value = keep_p ? gimple_call_arg (g, 1) : boolean_false_node;
+
+ update_call_from_tree (&gsi, folded_value);
+ FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
+ {
+ FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+ SET_USE (use_p, folded_value);
+ update_stmt (use_stmt);
+ }
+}
+
/* Set the uids of all the statements in basic blocks inside loop
represented by LOOP_VINFO. LOOP_VECTORIZED_CALL is the internal
call guarding the loop which has been if converted. */
@@ -595,7 +656,7 @@ vectorize_loops (void)
else
{
loop_vec_info loop_vinfo, orig_loop_vinfo;
- gimple *loop_vectorized_call;
+ gimple *loop_vectorized_call, *loop_dist_alias_call;
try_vectorize:
if (!((flag_tree_loop_vectorize
&& optimize_loop_nest_for_speed_p (loop))
@@ -603,6 +664,7 @@ vectorize_loops (void)
continue;
orig_loop_vinfo = NULL;
loop_vectorized_call = vect_loop_vectorized_call (loop);
+ loop_dist_alias_call = vect_loop_dist_alias_call (loop);
vectorize_epilogue:
vect_location = find_loop_location (loop);
if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOCATION
@@ -710,6 +772,12 @@ vectorize_loops (void)
loop_vectorized_call = NULL;
ret |= TODO_cleanup_cfg;
}
+ if (loop_dist_alias_call)
+ {
+ fold_loop_dist_alias_call (loop_dist_alias_call, true);
+ loop_dist_alias_call = NULL;
+ ret |= TODO_cleanup_cfg;
+ }
if (new_loop)
{
@@ -743,6 +811,15 @@ vectorize_loops (void)
{
fold_loop_vectorized_call (g, boolean_false_node);
ret |= TODO_cleanup_cfg;
+ g = NULL;
+ }
+ else
+ g = vect_loop_dist_alias_call (loop);
+
+ if (g)
+ {
+ fold_loop_dist_alias_call (g, false);
+ ret |= TODO_cleanup_cfg;
}
}
}
--
1.9.1
