On 11/9/21 14:37, Richard Biener wrote:
On Mon, Nov 8, 2021 at 8:45 PM Andrew MacLeod <amacl...@redhat.com> wrote:
On 11/8/21 10:05 AM, Martin Liška wrote:
On 9/28/21 22:39, Andrew MacLeod wrote:
In Theory, modifying the IL should be fine, it happens already in
places, but its not extensively tested under those conditions yet.
Hello Andrew.
I've just tried using a global gimple_ranger and it crashes when loop
unswitching duplicates
some BBs.
Please try the attached patch for:
hey Martin,
try using this in your tree. Since nothing else is using a growing BB
right now, I'll let you work with it and see if everything works as
expected before checking it in, just in case we need more tweaking.
With this,
make RUNTESTFLAGS=dg.exp=loop-unswitch*.c check-gcc
runs clean.
basically, I tried to grow it by either a factor of 10% for the current
BB size when the grow is requested, or some double the needed extra
size, or 128... whichever value is "maximum" That means it shoudnt be
asking for tooo much each time, but also not a minimum amount.
Im certainly open to suggestion on how much to grow it each time.
Note the vector being grown is ONLY fo the SSA_NAme being asked for.. so
it really an on-demand thing just for specific names, in your case,
mostly just the switch index.
Let me know how this works for you, and if you have any other issues.
So I think in the end we shouldn't need the growing. Ideally we'd do all
the analysis before the first transform, but for that we'd need ranger to
be able to "simplify" conditions based on a known true/false predicate
that's not yet in the IL. Consider
for (;;)
{
if (invariant < 3) // A
{
...
}
if (invariant < 5) // B
{
...
}
}
unswitch analysis will run into the condition 'A' and determine the loop
can be unswitched with the condition 'invariant < 3'. To be able to
perform cost assessment and to avoid redundant unswitching we
want to determine that if we unswitch with 'invariant < 3' being
true then the condition at 'B' is true as well before actually inserting
the if (invariant < 3) outside of the loop.
So I'm thinking of assigning a gimple_uid to each condition we want to
unswitch on and have an array indexed by the uid with meta-data on
the unswitch opportunity, the "related" conditions could be marked with
the same uid (or some other), and the folding result recorded so that
at transform time we can just do the appropriate replacement without
invoking ranger again.
Calculating all this before transformation is quite ambitious based on the code
we have now.
Note one can have in a loop:
if (a > 100)
...
switch (a)
case 1000:
...
case 20:
...
case 200:
...
which means the first predicate effectively makes some cases unreachable.
Moreover
one can have
if (a > 100 && b < 300)
...
and more complex conditions.
Now, but how do we arrange for the ranger analysis here?
That's likely something we need support from ranger, yes.
We might also somehow want to remember that on the
'invariant < 3' == false copy of the loop there's still the
unswitching opportunity on 'invariant < 5', but not on the
'invariant < 5' == true copy.
Currently unswitching uses a custom simplify_using_entry_checks
which tries to do simplification only after the fact (and so costing
also is far from costing the true cost and ordering of the opportunities
to do the best first is not implemented either).
I'm sending updated version of the patch where I changed:
- simplify_using_entry_checks is put back for the floating point expressions
- all scans utilize scan-tree-dump-times
- some new tests were added
- global ranger is used (I rely on the growing patch provided by Andrew)
- better ranger API is used for gcond expression: ranger.range_of_stmt (r, stmt) &&
r.singleton_p (&result))
- auto_edge_flag is used now
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
Thoughts?
Martin
Richard.
Andrew
From cd14c58668623b3028764d9209fd6b5510939e29 Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Wed, 1 Sep 2021 13:04:15 +0200
Subject: [PATCH] Loop unswitching: support gswitch statements.
The patch extends the loop unswitching pass so that gswitch
statements are supported. The pass now uses ranger which marks
switch edges that are known to be unreachable in a versioned loop.
gcc/ChangeLog:
* tree-cfg.c (gimple_lv_add_condition_to_bb): Support non-gimple
expressions that needs to be gimplified.
* tree-ssa-loop-unswitch.c (tree_unswitch_loop): Add new
cond_edge argument.
(tree_may_unswitch_on): Support gswitch statements.
(clean_up_switches): New function.
(tree_ssa_unswitch_loops): Call clean_up_switches.
(tree_unswitch_single_loop): Change assumptions.
gcc/testsuite/ChangeLog:
* gcc.dg/loop-unswitch-6.c: New test.
* gcc.dg/loop-unswitch-7.c: New test.
* gcc.dg/loop-unswitch-8.c: New test.
* gcc.dg/loop-unswitch-9.c: New test.
* gcc.dg/loop-unswitch-10.c: New test.
* gcc.dg/loop-unswitch-11.c: New test.
Co-Authored-By: Richard Biener <rguent...@suse.de>
---
gcc/testsuite/gcc.dg/loop-unswitch-10.c | 28 +++
gcc/testsuite/gcc.dg/loop-unswitch-11.c | 60 ++++++
gcc/testsuite/gcc.dg/loop-unswitch-6.c | 56 +++++
gcc/testsuite/gcc.dg/loop-unswitch-7.c | 45 ++++
gcc/testsuite/gcc.dg/loop-unswitch-8.c | 28 +++
gcc/testsuite/gcc.dg/loop-unswitch-9.c | 34 +++
gcc/tree-cfg.c | 7 +-
gcc/tree-ssa-loop-unswitch.c | 272 +++++++++++++++++++-----
8 files changed, 479 insertions(+), 51 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/loop-unswitch-10.c
create mode 100644 gcc/testsuite/gcc.dg/loop-unswitch-11.c
create mode 100644 gcc/testsuite/gcc.dg/loop-unswitch-6.c
create mode 100644 gcc/testsuite/gcc.dg/loop-unswitch-7.c
create mode 100644 gcc/testsuite/gcc.dg/loop-unswitch-8.c
create mode 100644 gcc/testsuite/gcc.dg/loop-unswitch-9.c
diff --git a/gcc/testsuite/gcc.dg/loop-unswitch-10.c b/gcc/testsuite/gcc.dg/loop-unswitch-10.c
new file mode 100644
index 00000000000..747de272935
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/loop-unswitch-10.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -funswitch-loops -fdump-tree-unswitch-details" } */
+
+int
+foo(double *a, double *b, double *c, double *d, double *r, int size, float order)
+{
+ for (int i = 0; i < size; i++)
+ {
+ double tmp;
+
+ if (order == 1.f)
+ tmp = -8 * a[i];
+ else
+ tmp = -4 * b[i];
+
+ double x = 3 * tmp + d[i] + tmp;
+
+ if (order == 1.f)
+ x += 2;
+
+ double y = 3.4f * tmp + d[i];
+ r[i] = x + y;
+ }
+
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 1.0e" 1 "unswitch" } } */
diff --git a/gcc/testsuite/gcc.dg/loop-unswitch-11.c b/gcc/testsuite/gcc.dg/loop-unswitch-11.c
new file mode 100644
index 00000000000..30f4f347f7b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/loop-unswitch-11.c
@@ -0,0 +1,60 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -funswitch-loops -fdump-tree-unswitch-details --param=max-unswitch-insns=1000 --param=max-unswitch-level=10" } */
+
+int
+__attribute__((noipa))
+foo(double *a, double *b, double *c, double *d, double *r, int size, int order)
+{
+ for (int i = 0; i < size; i++)
+ {
+ double tmp, tmp2;
+
+ if (order <= 0)
+ tmp = 123;
+
+ switch(order)
+ {
+ case 0:
+ tmp += -8 * a[i];
+ tmp2 = 2 * b[i];
+ break;
+ case 1:
+ tmp = 3 * a[i] - 2 * b[i];
+ tmp2 = 5 * b[i] - 2 * c[i];
+ break;
+ case 2:
+ tmp = 9 * a[i] + 2 * b[i] + c[i];
+ tmp2 = 4 * b[i] + 2 * c[i] + 8 * d[i];
+ break;
+ case 3:
+ tmp = 3 * a[i] + 2 * b[i] - c[i];
+ tmp2 = b[i] - 2 * c[i] + 8 * d[i];
+ break;
+ defaut:
+ __builtin_unreachable ();
+ }
+
+ double x = 3 * tmp + d[i] + tmp;
+ double y = 3.4f * tmp + d[i] + tmp2;
+ r[i] = x + y;
+ }
+
+ return 0;
+}
+
+#define N 16 * 1024
+double aa[N], bb[N], cc[N], dd[N], rr[N];
+
+int main()
+{
+ for (int i = 0; i < 100 * 1000; i++)
+ foo (aa, bb, cc, dd, rr, N, i % 4);
+}
+
+
+/* Test that we actually unswitched something. */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* <= 0" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 0" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 1" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 2" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 3" 1 "unswitch" } } */
diff --git a/gcc/testsuite/gcc.dg/loop-unswitch-6.c b/gcc/testsuite/gcc.dg/loop-unswitch-6.c
new file mode 100644
index 00000000000..315d6850877
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/loop-unswitch-6.c
@@ -0,0 +1,56 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -funswitch-loops -fdump-tree-unswitch-details --param=max-unswitch-insns=1000 --param=max-unswitch-level=10" } */
+
+int
+__attribute__((noipa))
+foo(double *a, double *b, double *c, double *d, double *r, int size, int order)
+{
+ for (int i = 0; i < size; i++)
+ {
+ double tmp, tmp2;
+
+ switch(order)
+ {
+ case 0:
+ tmp = -8 * a[i];
+ tmp2 = 2 * b[i];
+ break;
+ case 1:
+ tmp = 3 * a[i] - 2 * b[i];
+ tmp2 = 5 * b[i] - 2 * c[i];
+ break;
+ case 2:
+ tmp = 9 * a[i] + 2 * b[i] + c[i];
+ tmp2 = 4 * b[i] + 2 * c[i] + 8 * d[i];
+ break;
+ case 3:
+ tmp = 3 * a[i] + 2 * b[i] - c[i];
+ tmp2 = b[i] - 2 * c[i] + 8 * d[i];
+ break;
+ defaut:
+ __builtin_unreachable ();
+ }
+
+ double x = 3 * tmp + d[i] + tmp;
+ double y = 3.4f * tmp + d[i] + tmp2;
+ r[i] = x + y;
+ }
+
+ return 0;
+}
+
+#define N 16 * 1024
+double aa[N], bb[N], cc[N], dd[N], rr[N];
+
+int main()
+{
+ for (int i = 0; i < 100 * 1000; i++)
+ foo (aa, bb, cc, dd, rr, N, i % 4);
+}
+
+
+/* Test that we actually unswitched something. */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 0" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 1" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 2" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 3" 1 "unswitch" } } */
diff --git a/gcc/testsuite/gcc.dg/loop-unswitch-7.c b/gcc/testsuite/gcc.dg/loop-unswitch-7.c
new file mode 100644
index 00000000000..efabd52886c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/loop-unswitch-7.c
@@ -0,0 +1,45 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -funswitch-loops -fdump-tree-unswitch-details --param=max-unswitch-insns=1000 --param=max-unswitch-level=10" } */
+
+int
+foo(double *a, double *b, double *c, double *d, double *r, int size, int order)
+{
+ for (int i = 0; i < size; i++)
+ {
+ double tmp, tmp2;
+
+ switch(order)
+ {
+ case 5 ... 6:
+ case 9:
+ tmp = -8 * a[i];
+ tmp2 = 2 * b[i];
+ break;
+ case 11:
+ tmp = 3 * a[i] - 2 * b[i];
+ tmp2 = 5 * b[i] - 2 * c[i];
+ break;
+ case 22:
+ tmp = 9 * a[i] + 2 * b[i] + c[i];
+ tmp2 = 4 * b[i] + 2 * c[i] + 8 * d[i];
+ break;
+ case 33:
+ tmp = 3 * a[i] + 2 * b[i] - c[i];
+ tmp2 = b[i] - 2 * c[i] + 8 * d[i];
+ break;
+ defaut:
+ __builtin_unreachable ();
+ }
+
+ double x = 3 * tmp + d[i] + tmp;
+ double y = 3.4f * tmp + d[i] + tmp2;
+ r[i] = x + y;
+ }
+
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order_.* >= 5 & order_.* <= 6 \\| order_.* == 9" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 1" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 2" 1 "unswitch" } } */
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 3" 1 "unswitch" } } */
diff --git a/gcc/testsuite/gcc.dg/loop-unswitch-8.c b/gcc/testsuite/gcc.dg/loop-unswitch-8.c
new file mode 100644
index 00000000000..4cec1f53bcc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/loop-unswitch-8.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -funswitch-loops -fdump-tree-unswitch-details" } */
+
+int
+foo(double *a, double *b, double *c, double *d, double *r, int size, int order)
+{
+ for (int i = 0; i < size; i++)
+ {
+ double tmp;
+
+ if (order == 1)
+ tmp = -8 * a[i];
+ else
+ tmp = -4 * b[i];
+
+ double x = 3 * tmp + d[i] + tmp;
+
+ if (order == 1)
+ x += 2;
+
+ double y = 3.4f * tmp + d[i];
+ r[i] = x + y;
+ }
+
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* == 1" 1 "unswitch" } } */
diff --git a/gcc/testsuite/gcc.dg/loop-unswitch-9.c b/gcc/testsuite/gcc.dg/loop-unswitch-9.c
new file mode 100644
index 00000000000..3058d4a5b38
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/loop-unswitch-9.c
@@ -0,0 +1,34 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -funswitch-loops -fdump-tree-unswitch-details" } */
+
+int
+foo(double *a, double *b, double *c, double *d, double *r, int size, unsigned order)
+{
+ for (int i = 0; i < size; i++)
+ {
+ double tmp;
+
+ switch (order)
+ {
+ case 0 ... 4:
+ tmp = -8 * a[i];
+ break;
+ default:
+ tmp = -4 * b[i];
+ break;
+ }
+
+ double x = 3 * tmp + d[i] + tmp;
+
+ /* This should not be unswitched as it's mutually excluded with case 0 ... 4. */
+ if (order >= 5)
+ x += 2;
+
+ double y = 3.4f * tmp + d[i];
+ r[i] = x + y;
+ }
+
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-times ";; Unswitching loop with condition: order.* <= 4" 1 "unswitch" } } */
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 8ed8c69b5b1..7db54f1cda2 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -9062,11 +9062,16 @@ gimple_lv_add_condition_to_bb (basic_block first_head ATTRIBUTE_UNUSED,
edge e0;
/* Build new conditional expr */
+ gsi = gsi_last_bb (cond_bb);
+
+ cond_expr = force_gimple_operand_gsi_1 (&gsi, cond_expr,
+ is_gimple_condexpr_for_cond,
+ NULL_TREE, false,
+ GSI_CONTINUE_LINKING);
new_cond_expr = gimple_build_cond_from_tree (cond_expr,
NULL_TREE, NULL_TREE);
/* Add new cond in cond_bb. */
- gsi = gsi_last_bb (cond_bb);
gsi_insert_after (&gsi, new_cond_expr, GSI_NEW_STMT);
/* Adjust edges appropriately to connect new head with first head
diff --git a/gcc/tree-ssa-loop-unswitch.c b/gcc/tree-ssa-loop-unswitch.c
index fe4dacc0833..bb4ff760166 100644
--- a/gcc/tree-ssa-loop-unswitch.c
+++ b/gcc/tree-ssa-loop-unswitch.c
@@ -37,6 +37,10 @@ along with GCC; see the file COPYING3. If not see
#include "gimple-iterator.h"
#include "cfghooks.h"
#include "tree-ssa-loop-manip.h"
+#include "cfganal.h"
+#include "tree-cfgcleanup.h"
+#include "tree-pretty-print.h"
+#include "gimple-range.h"
/* This file implements the loop unswitching, i.e. transformation of loops like
@@ -74,9 +78,10 @@ along with GCC; see the file COPYING3. If not see
tree-ssa-loop-im.c ensures that all the suitable conditions are in this
shape. */
-static class loop *tree_unswitch_loop (class loop *, basic_block, tree);
-static bool tree_unswitch_single_loop (class loop *, int);
-static tree tree_may_unswitch_on (basic_block, class loop *);
+static class loop *tree_unswitch_loop (class loop *, basic_block, tree, edge);
+static bool tree_unswitch_single_loop (class loop *, int, const auto_edge_flag &);
+static tree tree_may_unswitch_on (basic_block, class loop *, edge *,
+ const auto_edge_flag &);
static bool tree_unswitch_outer_loop (class loop *);
static edge find_loop_guard (class loop *);
static bool empty_bb_without_guard_p (class loop *, basic_block);
@@ -84,6 +89,7 @@ static bool used_outside_loop_p (class loop *, tree);
static void hoist_guard (class loop *, edge);
static bool check_exit_phi (class loop *);
static tree get_vop_from_header (class loop *);
+static void clean_up_switches (const auto_edge_flag &ignored_edge_flag);
/* Main entry point. Perform loop unswitching on all suitable loops. */
@@ -91,19 +97,23 @@ unsigned int
tree_ssa_unswitch_loops (void)
{
bool changed = false;
+ auto_edge_flag ignored_edge_flag (cfun);
/* Go through all loops starting from innermost. */
for (auto loop : loops_list (cfun, LI_FROM_INNERMOST))
{
if (!loop->inner)
/* Unswitch innermost loop. */
- changed |= tree_unswitch_single_loop (loop, 0);
+ changed |= tree_unswitch_single_loop (loop, 0, ignored_edge_flag);
else
changed |= tree_unswitch_outer_loop (loop);
}
if (changed)
- return TODO_cleanup_cfg;
+ {
+ clean_up_switches (ignored_edge_flag);
+ return TODO_cleanup_cfg;
+ }
return 0;
}
@@ -182,47 +192,115 @@ is_maybe_undefined (const tree name, gimple *stmt, class loop *loop)
}
/* Checks whether we can unswitch LOOP on condition at end of BB -- one of its
- basic blocks (for what it means see comments below). */
+ basic blocks (for what it means see comments below).
+ When a gswitch case is returned, fill up COND_EDGE for it. */
static tree
-tree_may_unswitch_on (basic_block bb, class loop *loop)
+tree_may_unswitch_on (basic_block bb, class loop *loop, edge *cond_edge,
+ const auto_edge_flag &ignored_edge_flag)
{
gimple *last, *def;
- gcond *stmt;
- tree cond, use;
+ tree use;
basic_block def_bb;
ssa_op_iter iter;
/* BB must end in a simple conditional jump. */
last = last_stmt (bb);
- if (!last || gimple_code (last) != GIMPLE_COND)
- return NULL_TREE;
- stmt = as_a <gcond *> (last);
+ if (gcond *stmt = safe_dyn_cast <gcond *> (last))
+ {
+ /* To keep the things simple, we do not directly remove the conditions,
+ but just replace tests with 0 != 0 resp. 1 != 0. Prevent the infinite
+ loop where we would unswitch again on such a condition. */
+ if (gimple_cond_true_p (stmt) || gimple_cond_false_p (stmt))
+ return NULL_TREE;
- /* To keep the things simple, we do not directly remove the conditions,
- but just replace tests with 0 != 0 resp. 1 != 0. Prevent the infinite
- loop where we would unswitch again on such a condition. */
- if (gimple_cond_true_p (stmt) || gimple_cond_false_p (stmt))
- return NULL_TREE;
+ /* Condition must be invariant. */
+ FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
+ {
+ def = SSA_NAME_DEF_STMT (use);
+ def_bb = gimple_bb (def);
+ if (def_bb
+ && flow_bb_inside_loop_p (loop, def_bb))
+ return NULL_TREE;
+ /* Unswitching on undefined values would introduce undefined
+ behavior that the original program might never exercise. */
+ if (is_maybe_undefined (use, stmt, loop))
+ return NULL_TREE;
+ }
- /* Condition must be invariant. */
- FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
+ edge e1 = EDGE_SUCC (bb, 0);
+ edge e2 = EDGE_SUCC (bb, 1);
+ *cond_edge = e1->flags & EDGE_TRUE_VALUE ? e1 : e2;
+ return build2 (gimple_cond_code (stmt), boolean_type_node,
+ gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
+ }
+ else if (gswitch *stmt = safe_dyn_cast <gswitch *> (last))
{
- def = SSA_NAME_DEF_STMT (use);
+ unsigned nlabels = gimple_switch_num_labels (stmt);
+ tree idx = gimple_switch_index (stmt);
+ if (TREE_CODE (idx) != SSA_NAME
+ || nlabels < 1)
+ return NULL_TREE;
+ /* Index must be invariant. */
+ def = SSA_NAME_DEF_STMT (idx);
def_bb = gimple_bb (def);
if (def_bb
&& flow_bb_inside_loop_p (loop, def_bb))
return NULL_TREE;
/* Unswitching on undefined values would introduce undefined
behavior that the original program might never exercise. */
- if (is_maybe_undefined (use, stmt, loop))
+ if (is_maybe_undefined (idx, stmt, loop))
return NULL_TREE;
- }
- cond = build2 (gimple_cond_code (stmt), boolean_type_node,
- gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->succs)
+ {
+ if (!(e->flags & ignored_edge_flag))
+ {
+ /* Build compound expression for all cases leading
+ to this edge. */
+ tree expr = NULL_TREE;
+ for (unsigned i = 1; i < gimple_switch_num_labels (stmt); ++i)
+ {
+ tree lab = gimple_switch_label (stmt, i);
+ basic_block dest = label_to_block (cfun, CASE_LABEL (lab));
+ edge e2 = find_edge (gimple_bb (stmt), dest);
+ if (e == e2)
+ {
+ tree cmp;
+ if (CASE_HIGH (lab) != NULL_TREE)
+ {
+ tree cmp1 = build2 (GE_EXPR, boolean_type_node, idx,
+ CASE_LOW (lab));
+ tree cmp2 = build2 (LE_EXPR, boolean_type_node, idx,
+ CASE_HIGH (lab));
+ cmp = build2 (BIT_AND_EXPR, boolean_type_node, cmp1,
+ cmp2);
+ }
+ else
+ cmp = build2 (EQ_EXPR, boolean_type_node, idx,
+ CASE_LOW (lab));
+
+ /* Combine the expression with the existing one. */
+ if (expr == NULL_TREE)
+ expr = cmp;
+ else
+ expr = build2 (BIT_IOR_EXPR, boolean_type_node, expr,
+ cmp);
+ }
+ }
- return cond;
+ if (expr != NULL_TREE)
+ {
+ *cond_edge = e;
+ return expr;
+ }
+ }
+ }
+ }
+
+ return NULL_TREE;
}
/* Simplifies COND using checks in front of the entry of the LOOP. Just very
@@ -263,12 +341,14 @@ simplify_using_entry_checks (class loop *loop, tree cond)
grow exponentially. */
static bool
-tree_unswitch_single_loop (class loop *loop, int num)
+tree_unswitch_single_loop (class loop *loop, int num,
+ const auto_edge_flag &ignored_edge_flag)
{
basic_block *bbs;
class loop *nloop;
unsigned i, found;
tree cond = NULL_TREE;
+ edge cond_edge = NULL;
gimple *stmt;
bool changed = false;
HOST_WIDE_INT iterations;
@@ -311,11 +391,13 @@ tree_unswitch_single_loop (class loop *loop, int num)
bbs = get_loop_body (loop);
found = loop->num_nodes;
+ gimple_ranger ranger;
while (1)
{
/* Find a bb to unswitch on. */
for (; i < loop->num_nodes; i++)
- if ((cond = tree_may_unswitch_on (bbs[i], loop)))
+ if ((cond = tree_may_unswitch_on (bbs[i], loop, &cond_edge,
+ ignored_edge_flag)))
break;
if (i == loop->num_nodes)
@@ -333,24 +415,77 @@ tree_unswitch_single_loop (class loop *loop, int num)
break;
}
- cond = simplify_using_entry_checks (loop, cond);
stmt = last_stmt (bbs[i]);
- if (integer_nonzerop (cond))
+ gcond *condition = dyn_cast<gcond *> (stmt);
+ gswitch *swtch = dyn_cast<gswitch *> (stmt);
+
+ if (condition != NULL)
{
- /* Remove false path. */
- gimple_cond_set_condition_from_tree (as_a <gcond *> (stmt),
- boolean_true_node);
- changed = true;
+ tree result;
+ int_range_max r;
+
+ if (ranger.range_of_stmt (r, stmt) && r.singleton_p (&result))
+ {
+ gimple_cond_set_condition_from_tree (condition,
+ result);
+ update_stmt (condition);
+ changed = true;
+ }
+ else
+ {
+ /* FIXME: Remove legacy code for floating point type that
+ is currently not supported by ranger. */
+ cond = simplify_using_entry_checks (loop, cond);
+ if (integer_nonzerop (cond))
+ {
+ gimple_cond_set_condition_from_tree (condition,
+ boolean_true_node);
+ update_stmt (condition);
+ changed = true;
+ }
+ else if (integer_zerop (cond))
+ {
+ /* Remove true path. */
+ gimple_cond_set_condition_from_tree (condition,
+ boolean_false_node);
+ update_stmt (condition);
+ changed = true;
+ }
+ }
}
- else if (integer_zerop (cond))
+ else if (swtch != NULL)
{
- /* Remove true path. */
- gimple_cond_set_condition_from_tree (as_a <gcond *> (stmt),
- boolean_false_node);
- changed = true;
+ hash_set<edge> ignored_edges;
+ unsigned nlabels = gimple_switch_num_labels (swtch);
+ tree index_candidate = NULL_TREE;
+
+ for (unsigned i = 0; i < nlabels; ++i)
+ {
+ tree lab = gimple_switch_label (swtch, i);
+ basic_block dest = label_to_block (cfun, CASE_LABEL (lab));
+ edge e = find_edge (gimple_bb (stmt), dest);
+
+ int_range_max r;
+ if (ranger.range_on_edge (r, e, gimple_switch_index (swtch))
+ && r.undefined_p ())
+ {
+ e->flags |= ignored_edge_flag;
+ ignored_edges.add (e);
+ }
+ else
+ index_candidate = CASE_LOW (lab);
+ }
+
+ if (index_candidate != NULL_TREE
+ && ignored_edges.elements () == EDGE_COUNT (bbs[i]->succs) - 1)
+ {
+ gimple_switch_set_index (swtch, index_candidate);
+ update_stmt (swtch);
+ }
}
+
/* Do not unswitch too much. */
- else if (num > param_max_unswitch_level)
+ if (num > param_max_unswitch_level)
{
i++;
continue;
@@ -371,7 +506,6 @@ tree_unswitch_single_loop (class loop *loop, int num)
break;
}
- update_stmt (stmt);
i++;
}
@@ -435,7 +569,8 @@ tree_unswitch_single_loop (class loop *loop, int num)
/* Find a bb to unswitch on. */
for (; found < loop->num_nodes; found++)
if ((bbs[found]->flags & BB_REACHABLE)
- && (cond = tree_may_unswitch_on (bbs[found], loop)))
+ && (cond = tree_may_unswitch_on (bbs[found], loop, &cond_edge,
+ ignored_edge_flag)))
break;
if (found == loop->num_nodes)
@@ -446,11 +581,15 @@ tree_unswitch_single_loop (class loop *loop, int num)
}
if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, ";; Unswitching loop\n");
+ {
+ fprintf (dump_file, ";; Unswitching loop with condition: ");
+ print_generic_expr (dump_file, cond);
+ fprintf (dump_file, "\n");
+ }
initialize_original_copy_tables ();
/* Unswitch the loop on this condition. */
- nloop = tree_unswitch_loop (loop, bbs[found], cond);
+ nloop = tree_unswitch_loop (loop, bbs[found], cond, cond_edge);
if (!nloop)
{
free_original_copy_tables ();
@@ -463,8 +602,8 @@ tree_unswitch_single_loop (class loop *loop, int num)
free_original_copy_tables ();
/* Invoke itself on modified loops. */
- tree_unswitch_single_loop (nloop, num + 1);
- tree_unswitch_single_loop (loop, num + 1);
+ tree_unswitch_single_loop (nloop, num + 1, ignored_edge_flag);
+ tree_unswitch_single_loop (loop, num + 1, ignored_edge_flag);
free (bbs);
return true;
}
@@ -476,18 +615,15 @@ tree_unswitch_single_loop (class loop *loop, int num)
static class loop *
tree_unswitch_loop (class loop *loop,
- basic_block unswitch_on, tree cond)
+ basic_block unswitch_on, tree cond, edge cond_edge)
{
profile_probability prob_true;
- edge edge_true, edge_false;
/* Some sanity checking. */
gcc_assert (flow_bb_inside_loop_p (loop, unswitch_on));
- gcc_assert (EDGE_COUNT (unswitch_on->succs) == 2);
gcc_assert (loop->inner == NULL);
- extract_true_false_edges_from_block (unswitch_on, &edge_true, &edge_false);
- prob_true = edge_true->probability;
+ prob_true = cond_edge->probability;
return loop_version (loop, unshare_expr (cond),
NULL, prob_true,
prob_true.invert (),
@@ -965,6 +1101,42 @@ check_exit_phi (class loop *loop)
return true;
}
+/* Remove all dead cases from switches that are unswitched. */
+
+static void
+clean_up_switches (const auto_edge_flag &ignored_edge_flag)
+{
+ basic_block bb;
+
+ FOR_EACH_BB_FN (bb, cfun)
+ {
+ gimple *last = last_stmt (bb);
+ if (gswitch *stmt = safe_dyn_cast <gswitch *> (last))
+ {
+ unsigned nlabels = gimple_switch_num_labels (stmt);
+ unsigned index = 1;
+ for (unsigned i = 1; i < nlabels; ++i)
+ {
+ tree lab = gimple_switch_label (stmt, i);
+ basic_block dest = label_to_block (cfun, CASE_LABEL (lab));
+ edge e = find_edge (gimple_bb (stmt), dest);
+ if (e == NULL)
+ ; /* The edge is already removed. */
+ else if (e->flags & ignored_edge_flag)
+ remove_edge (e);
+ else
+ {
+ gimple_switch_set_label (stmt, index, lab);
+ ++index;
+ }
+ }
+
+ if (index != nlabels)
+ gimple_switch_set_num_labels (stmt, index);
+ }
+ }
+}
+
/* Loop unswitching pass. */
namespace {
--
2.33.1
