This adds some extra checks to see if we can remove the casts
for signed integer overflow reasons while doing a negative.
This is needed more due to the recent patch which adds them
in some cases.
Bootstrapped and tested on x86_64-linux-gnu.
PR tree-optimization/107765
gcc/ChangeLog:
* match.pd (`(cast)-(cast)a`): Expand to use ranger
to see if we can remove the casts.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/neg-cast-1.c: New test.
* gcc.dg/tree-ssa/neg-cast-4.c: New test.
Signed-off-by: Andrea Pinski <[email protected]>
---
gcc/match.pd | 37 ++++++++++++++++++----
gcc/testsuite/gcc.dg/tree-ssa/neg-cast-1.c | 23 ++++++++++++++
gcc/testsuite/gcc.dg/tree-ssa/neg-cast-4.c | 16 ++++++++++
3 files changed, 69 insertions(+), 7 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/neg-cast-1.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/neg-cast-4.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 751f5571183..8de356b102c 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1233,15 +1233,38 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
show up. Else it is safe if the negation is done in an unsigned type.
Note the outer cast cannot be a boolean type as the only valid values
are 0,-1/1 (depending on the signedness of the boolean) and the negative
- is there to get the correct value. */
+ is there to get the correct value.
+ Also handle the case where we */
(simplify
- (convert (negate:s@1 (convert:s @0)))
+ (convert (negate:s@1 (convert:s@ic @0)))
(if (INTEGRAL_TYPE_P (type)
- && tree_nop_conversion_p (type, TREE_TYPE (@1))
- && (TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (@0))
- || TYPE_UNSIGNED (type))
- && TREE_CODE (type) != BOOLEAN_TYPE)
- (negate (convert @0))))
+ && tree_nop_conversion_p (type, TREE_TYPE (@1)))
+ (with {
+ bool can_handle = false;
+#if GIMPLE
+ int_range_max vr;
+#endif
+ if ((TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (@0))
+ || TYPE_UNSIGNED (type))
+ && TREE_CODE (type) != BOOLEAN_TYPE)
+ can_handle = true;
+ else if (wi::ges_p (tree_nonzero_bits (@ic), 0))
+ can_handle = true;
+#if GIMPLE
+ /* If we know that @0 does not contain signed max, then the
+ conversion can be removed. */
+ else if (TREE_CODE (@0) == SSA_NAME
+ && types_match (type, TREE_TYPE (@0))
+ && get_range_query (cfun)->range_of_expr (vr, @0)
+ && !vr.undefined_p ())
+ {
+ tree stype = signed_type_for (type);
+ can_handle = !vr.contains_p (wi::min_value (stype));
+ }
+#endif
+ }
+ (if (can_handle)
+ (negate (convert @0))))))
(for op (negate abs)
/* Simplify cos(-x) and cos(|x|) -> cos(x). Similarly for cosh. */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/neg-cast-1.c
b/gcc/testsuite/gcc.dg/tree-ssa/neg-cast-1.c
new file mode 100644
index 00000000000..ec5d0e15251
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/neg-cast-1.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized -fdump-tree-cddce1" } */
+/* PR tree-optimization/107765 */
+
+int a(int input)
+{
+ if (input == -__INT_MAX__-1) return 1;
+ unsigned t = input;
+ int tt = -t;
+ return tt == -input;
+}
+
+int b(int input)
+{
+ if (input == -__INT_MAX__-1) __builtin_trap();
+ unsigned t = input;
+ int tt = -t;
+ return tt;
+}
+
+/* { dg-final { scan-tree-dump "return 1" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "\\(unsigned int\\)" "cddce1" } } */
+/* { dg-final { scan-tree-dump-not "\\(int\\)" "cddce1" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/neg-cast-4.c
b/gcc/testsuite/gcc.dg/tree-ssa/neg-cast-4.c
new file mode 100644
index 00000000000..fe3fe6a2ecc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/neg-cast-4.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-phiopt2-details -fdump-tree-optimized" } */
+/* PR tree-optimization/107765 */
+
+int b(int input)
+{
+ if (input == -__INT_MAX__-1) return input;
+ unsigned t = input;
+ int tt = -t;
+ return tt;
+}
+
+/* { dg-final { scan-tree-dump-not "if " "optimized" } } */
+/* { dg-final { scan-tree-dump-times "\\(unsigned int\\)" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "\\(int\\)" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "converted to straightline code" 1
"phiopt2" } } */
--
2.43.0
