set_range_info should return TRUE only when it sets a new value. It was
currently returning true whenever it set a value, whether it was
different or not.
With this change, VRP no longer overwrites global ranges DOM has set.
2 testcases needed adjusting that were expecting VRP2 to set a range but
turns out it was really being set in DOM2. Instead they check for the
range in the final listing...
Bootstrapped on x86_64-pc-linux-gnu with no regressions. Pushed.
Andrew
From dae5de2a2353b928cc7099a78d88a40473abefd2 Mon Sep 17 00:00:00 2001
From: Andrew MacLeod <amacl...@redhat.com>
Date: Wed, 27 Sep 2023 12:34:16 -0400
Subject: [PATCH 1/5] Return TRUE only when a global value is updated.
set_range_info should return TRUE only when it sets a new value. VRP no
longer overwrites global ranges DOM has set. Check for ranges in the
final listing.
gcc/
* tree-ssanames.cc (set_range_info): Return true only if the
current value changes.
gcc/testsuite/
* gcc.dg/pr93917.c: Check for ranges in final optimized listing.
* gcc.dg/tree-ssa/vrp-unreachable.c: Ditto.
---
gcc/testsuite/gcc.dg/pr93917.c | 4 ++--
.../gcc.dg/tree-ssa/vrp-unreachable.c | 4 ++--
gcc/tree-ssanames.cc | 24 +++++++++----------
3 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/gcc/testsuite/gcc.dg/pr93917.c b/gcc/testsuite/gcc.dg/pr93917.c
index f09e1c41ae8..f636b77f45d 100644
--- a/gcc/testsuite/gcc.dg/pr93917.c
+++ b/gcc/testsuite/gcc.dg/pr93917.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-vrp1 -fdump-tree-vrp2" } */
+/* { dg-options "-O2 -fdump-tree-vrp1 -fdump-tree-vrp2 -fdump-tree-optimized-alias" } */
void f3(int n);
@@ -19,5 +19,5 @@ void f2(int*n)
/* { dg-final { scan-tree-dump-times "Global Export.*0, \\+INF" 1 "vrp1" } } */
/* { dg-final { scan-tree-dump-times "__builtin_unreachable" 1 "vrp1" } } */
-/* { dg-final { scan-tree-dump-times "Global Export.*0, \\+INF" 1 "vrp2" } } */
/* { dg-final { scan-tree-dump-times "__builtin_unreachable" 0 "vrp2" } } */
+/* { dg-final { scan-tree-dump-times "0, \\+INF" 2 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp-unreachable.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp-unreachable.c
index 5835dfc8dbc..4aad7f1be5d 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/vrp-unreachable.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp-unreachable.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-vrp1-alias -fdump-tree-vrp2-alias" } */
+/* { dg-options "-O2 -fdump-tree-vrp1 -fdump-tree-vrp2 -fdump-tree-optimized-alias" } */
void dead (unsigned n);
void alive (unsigned n);
@@ -39,4 +39,4 @@ void func (unsigned n, unsigned m)
/* { dg-final { scan-tree-dump-not "dead" "vrp1" } } */
/* { dg-final { scan-tree-dump-times "builtin_unreachable" 1 "vrp1" } } */
/* { dg-final { scan-tree-dump-not "builtin_unreachable" "vrp2" } } */
-/* { dg-final { scan-tree-dump-times "fff8 VALUE 0x0" 4 "vrp2" } } */
+/* { dg-final { scan-tree-dump-times "fff8 VALUE 0x0" 2 "optimized" } } */
diff --git a/gcc/tree-ssanames.cc b/gcc/tree-ssanames.cc
index 23387b90fe3..1eae411ac1c 100644
--- a/gcc/tree-ssanames.cc
+++ b/gcc/tree-ssanames.cc
@@ -418,10 +418,17 @@ set_range_info (tree name, const vrange &r)
if (r.undefined_p () || r.varying_p ())
return false;
+ // Pick up the current range, or VARYING if none.
tree type = TREE_TYPE (name);
+ Value_Range tmp (type);
+ if (range_info_p (name))
+ range_info_get_range (name, tmp);
+ else
+ tmp.set_varying (type);
+
if (POINTER_TYPE_P (type))
{
- if (r.nonzero_p ())
+ if (r.nonzero_p () && !tmp.nonzero_p ())
{
set_ptr_nonnull (name);
return true;
@@ -429,18 +436,11 @@ set_range_info (tree name, const vrange &r)
return false;
}
- /* If a global range already exists, incorporate it. */
- if (range_info_p (name))
- {
- Value_Range tmp (type);
- range_info_get_range (name, tmp);
- tmp.intersect (r);
- if (tmp.undefined_p ())
- return false;
+ // If the result doesn't change, or is undefined, return false.
+ if (!tmp.intersect (r) || tmp.undefined_p ())
+ return false;
- return range_info_set_range (name, tmp);
- }
- return range_info_set_range (name, r);
+ return range_info_set_range (name, tmp);
}
/* Set nonnull attribute to pointer NAME. */
--
2.41.0
