This patch actually addresses a few PRs.
The root PR was 97909. Ranger context functionality was added to
fold_const back in early November
(https://gcc.gnu.org/pipermail/gcc-patches/2021-November/583216.html)
The other 2 PRs mentioned (83072 and 83073) partially worked after this,
but the original patch did not change the result of the query in
expr_not_equal_to () to a multi-range object.
This patch simply changes the value_range variable in that routine to an
int_range<5> so we can pick up more precision. This in turn allows us to
capture all the tests as expected.
Bootstrapped on x86_64-pc-linux-gnu with no regressions.
OK for trunk?
Andrew
From 329626a426d21dfe484053f7b6ac4f2d0c14fa0e Mon Sep 17 00:00:00 2001
From: Andrew MacLeod <amacl...@redhat.com>
Date: Wed, 12 Jan 2022 13:31:08 -0500
Subject: [PATCH 2/2] Allow more precision when querying from fold_const.
fold_const::expr_not_equal_to queries for a current range, but still uses
the old value_range class. This is causing it to miss opportunities when
ranger can provide something better.
PR tree-optimization/83072
PR tree-optimization/83073
PR tree-optimization/97909
gcc/
* fold-const.c (expr_not_equal_to): Use a multi-range class.
gcc/testsuite/
* gcc.dg/pr83072-2.c: New.
* gcc.dg/pr83073.c: New.
---
gcc/fold-const.c | 2 +-
gcc/testsuite/gcc.dg/pr83072-2.c | 18 ++++++++++++++++++
gcc/testsuite/gcc.dg/pr83073.c | 10 ++++++++++
3 files changed, 29 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/pr83072-2.c
create mode 100644 gcc/testsuite/gcc.dg/pr83073.c
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 397fa9a03a1..7945b8d9eda 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -10734,7 +10734,7 @@ tree_expr_nonzero_p (tree t)
bool
expr_not_equal_to (tree t, const wide_int &w)
{
- value_range vr;
+ int_range<5> vr;
switch (TREE_CODE (t))
{
case INTEGER_CST:
diff --git a/gcc/testsuite/gcc.dg/pr83072-2.c b/gcc/testsuite/gcc.dg/pr83072-2.c
new file mode 100644
index 00000000000..f495f2582c4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr83072-2.c
@@ -0,0 +1,18 @@
+/* { dg-do compile} */
+/* { dg-options "-O2 -fdump-tree-evrp-details" } */
+
+int f1(int a, int b, int c){
+ if(c==0)__builtin_unreachable();
+ a *= c;
+ b *= c;
+ return a == b;
+}
+
+int f2(int a, int b, int c){
+ c |= 1;
+ a *= c;
+ b *= c;
+ return a == b;
+}
+
+/* { dg-final { scan-tree-dump-times "gimple_simplified to" 2 "evrp" } } */
diff --git a/gcc/testsuite/gcc.dg/pr83073.c b/gcc/testsuite/gcc.dg/pr83073.c
new file mode 100644
index 00000000000..1168ae822a4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr83073.c
@@ -0,0 +1,10 @@
+/* { dg-do compile} */
+/* { dg-options "-O2 -fdump-tree-evrp-details -fno-tree-fre -fno-tree-ccp -fno-tree-forwprop" } */
+
+int f(int x)
+{
+ x = x|1;
+ return x & 1;
+}
+
+/* { dg-final { scan-tree-dump "gimple_simplified to.* = 1" "evrp" } } */
--
2.17.2
