On 8/11/23 05:51, Richard Biener wrote:
On Fri, Aug 11, 2023 at 11:17 AM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
So it turns out there was a simplier way of starting to
improve VRP to start to fix PR 110131, PR 108360, and PR 108397.
That was rewrite test_for_singularity to use range_op_handler
and Value_Range.
This patch implements that and
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
I'm hoping Andrew/Aldy can have a look here.
Richard.
gcc/ChangeLog:
* vr-values.cc (test_for_singularity): Add edge argument
and rewrite using range_op_handler.
(simplify_compare_using_range_pairs): Use Value_Range
instead of value_range and update test_for_singularity call.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/vrp124.c: New test.
* gcc.dg/tree-ssa/vrp125.c: New test.
---
gcc/testsuite/gcc.dg/tree-ssa/vrp124.c | 44 +++++++++++++
gcc/testsuite/gcc.dg/tree-ssa/vrp125.c | 44 +++++++++++++
gcc/vr-values.cc | 91 ++++++++------------------
3 files changed, 114 insertions(+), 65 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/vrp124.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/vrp125.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp124.c
b/gcc/testsuite/gcc.dg/tree-ssa/vrp124.c
new file mode 100644
index 00000000000..6ccbda35d1b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp124.c
@@ -0,0 +1,44 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+/* Should be optimized to a == -100 */
+int g(int a)
+{
+ if (a == -100 || a >= 0)
+ ;
+ else
+ return 0;
+ return a < 0;
+}
+
+/* Should optimize to a == 0 */
+int f(int a)
+{
+ if (a == 0 || a > 100)
+ ;
+ else
+ return 0;
+ return a < 50;
+}
+
+/* Should be optimized to a == 0. */
+int f2(int a)
+{
+ if (a == 0 || a > 100)
+ ;
+ else
+ return 0;
+ return a < 100;
+}
+
+/* Should optimize to a == 100 */
+int f1(int a)
+{
+ if (a < 0 || a == 100)
+ ;
+ else
+ return 0;
+ return a > 50;
+}
+
+/* { dg-final { scan-tree-dump-not "goto " "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp125.c
b/gcc/testsuite/gcc.dg/tree-ssa/vrp125.c
new file mode 100644
index 00000000000..f6c2f8e35f1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp125.c
@@ -0,0 +1,44 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+/* Should be optimized to a == -100 */
+int g(int a)
+{
+ if (a == -100 || a == -50 || a >= 0)
+ ;
+ else
+ return 0;
+ return a < -50;
+}
+
+/* Should optimize to a == 0 */
+int f(int a)
+{
+ if (a == 0 || a == 50 || a > 100)
+ ;
+ else
+ return 0;
+ return a < 50;
+}
+
+/* Should be optimized to a == 0. */
+int f2(int a)
+{
+ if (a == 0 || a == 50 || a > 100)
+ ;
+ else
+ return 0;
+ return a < 25;
+}
+
+/* Should optimize to a == 100 */
+int f1(int a)
+{
+ if (a < 0 || a == 50 || a == 100)
+ ;
+ else
+ return 0;
+ return a > 50;
+}
+
+/* { dg-final { scan-tree-dump-not "goto " "optimized" } } */
diff --git a/gcc/vr-values.cc b/gcc/vr-values.cc
index a4fddd62841..7004b0224bd 100644
--- a/gcc/vr-values.cc
+++ b/gcc/vr-values.cc
@@ -907,66 +907,30 @@ simplify_using_ranges::simplify_bit_ops_using_ranges
a known value range VR.
If there is one and only one value which will satisfy the
- conditional, then return that value. Else return NULL.
-
- If signed overflow must be undefined for the value to satisfy
- the conditional, then set *STRICT_OVERFLOW_P to true. */
+ conditional on the EDGE, then return that value.
+ Else return NULL. */
static tree
test_for_singularity (enum tree_code cond_code, tree op0,
- tree op1, const value_range *vr)
+ tree op1, Value_Range vr, bool edge)
VR should be a "vrange &". THis is the top level base class for all
ranges of all types/kinds, and what we usually pass values around as if
we want tohem to be any kind. If this is inetger only, we'd pass a an
'irange &'
Value_Range is the opposite. Its the sink that contains one of each kind
of range and can switch around between them as needed. You do not want
to pass that by value! The generic engine uses these so it can suppose
floats. int, pointers, whatever...
{
- tree min = NULL;
- tree max = NULL;
-
- /* Extract minimum/maximum values which satisfy the conditional as it was
- written. */
- if (cond_code == LE_EXPR || cond_code == LT_EXPR)
+ /* This is already a singularity. */
+ if (cond_code == NE_EXPR || cond_code == EQ_EXPR)
+ return NULL;
+ auto range_op = range_op_handler (cond_code);
+ int_range<2> op1_range (TREE_TYPE (op0));
+ wide_int w = wi::to_wide (op1);
+ op1_range.set (TREE_TYPE (op1), w, w);
If this is only going to work with integers, you might want to check
that somewhere or switch to irange and int_range_max..
You can make it work with any kind (if you know op1 is a constant) by
simply doing
Value_Range op1_range (TREE_TYPE (op1))
get_global_range_query->range_of_expr (op1_range, op1)
That will convert trees to a the appropriate range... THis is also true
for integer constants... but you can also just do the WI conversion like
you do.
The routine also get confusing to read because it passes in op0 and
op1, but of course ranger uses op1 and op2 nomenclature, and it looks a
bit confusing :-P I'd change the operands passed in to op1 and op2 if
we are rewriting the routine.
+ Value_Range vr1(TREE_TYPE (op0));
+ if (range_op.op1_range (vr1, TREE_TYPE (op0),
+ edge ? range_true () : range_false (),
+ op1_range))
IF you decide to stick with integers, then you can just make vr1 an
int_range_max vr1;
You don't need the type in the declaration if you know its an irange.
Value_Range needs a type because it needs to know if its an integr or a
floating point (or whatever) that it is going ot be used as.
{
- min = TYPE_MIN_VALUE (TREE_TYPE (op0));
-
- max = op1;
- if (cond_code == LT_EXPR)
- {
- tree one = build_int_cst (TREE_TYPE (op0), 1);
- max = fold_build2 (MINUS_EXPR, TREE_TYPE (op0), max, one);
- /* Signal to compare_values_warnv this expr doesn't overflow. */
- if (EXPR_P (max))
- suppress_warning (max, OPT_Woverflow);
- }
- }
- else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
- {
- max = TYPE_MAX_VALUE (TREE_TYPE (op0));
-
- min = op1;
- if (cond_code == GT_EXPR)
- {
- tree one = build_int_cst (TREE_TYPE (op0), 1);
- min = fold_build2 (PLUS_EXPR, TREE_TYPE (op0), min, one);
- /* Signal to compare_values_warnv this expr doesn't overflow. */
- if (EXPR_P (min))
- suppress_warning (min, OPT_Woverflow);
- }
- }
-
- /* Now refine the minimum and maximum values using any
- value range information we have for op0. */
- if (min && max)
- {
- tree type = TREE_TYPE (op0);
- tree tmin = wide_int_to_tree (type, vr->lower_bound ());
- tree tmax = wide_int_to_tree (type, vr->upper_bound ());
- if (compare_values (tmin, min) == 1)
- min = tmin;
- if (compare_values (tmax, max) == -1)
- max = tmax;
-
- /* If the new min/max values have converged to a single value,
- then there is only one value which can satisfy the condition,
- return that value. */
- if (operand_equal_p (min, max, 0) && is_gimple_min_invariant (min))
- return min;
+ vr.intersect (vr1);
+ tree newop1;
+ /* If the updated range is just a singleton, then we can just do a
comparison */
+ if (vr.singleton_p (&newop1))
+ return newop1;
}
return NULL;
}
@@ -1224,9 +1188,9 @@ simplify_using_ranges::simplify_compare_using_ranges_1
(tree_code &cond_code, tr
&& cond_code != EQ_EXPR
&& TREE_CODE (op0) == SSA_NAME
&& INTEGRAL_TYPE_P (TREE_TYPE (op0))
- && is_gimple_min_invariant (op1))
+ && TREE_CODE (op1) == INTEGER_CST)
{
- value_range vr;
+ Value_Range vr (TREE_TYPE (op0));
OK, so we know they are integers.. you could just iuse int_range_max
vr; if you want to stick to integers
if (!query->range_of_expr (vr, op0, stmt))
vr.set_undefined ();
@@ -1235,20 +1199,17 @@ simplify_using_ranges::simplify_compare_using_ranges_1
(tree_code &cond_code, tr
able to simplify this conditional. */
if (!vr.undefined_p () && !vr.varying_p ())
{
- tree new_tree = test_for_singularity (cond_code, op0, op1, &vr);
+ tree new_tree = test_for_singularity (cond_code, op0, op1, vr,
+ true);
if (new_tree)
{
cond_code = EQ_EXPR;
op1 = new_tree;
happened = true;
}
-
- /* Try again after inverting the condition. We only deal
- with integral types here, so no need to worry about
- issues with inverting FP comparisons. */
- new_tree = test_for_singularity
- (invert_tree_comparison (cond_code, false),
- op0, op1, &vr);
+ /* Try again after inverting the condition. */
+ new_tree = test_for_singularity (cond_code, op0, op1, vr,
+ false);
if (new_tree)
{
cond_code = NE_EXPR;
--
2.31.1
Other than that, LGTM.
Andrew
