https://gcc.gnu.org/g:45a3277149d95a51cf9109cab87ee39a7dce73e2
commit r15-5380-g45a3277149d95a51cf9109cab87ee39a7dce73e2
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date: Sun Nov 17 20:21:58 2024 -0800
match: Fix the `max<a,b>==0` pattern for pointers [PR117646]
For pointers I forgot that BIT_IOR_EXPR is not valid so when
I added the pattern to convert `max<a,b> != 0` (r15-5356), GCC
would start to ICEing saying pointer types were not valid for
BIT_IOR_EXPR.
This fixes the problem by casting to the unsigned type of the
inner type. There was another way of fixing this to handling it
as `a == 0 & b == 0` but both match and reassoication (for pointers)
will then convert it back into the form I am creating here so
let's just use that form instead.
Bootstrapped and tested on x86_64-linux-gnu.
PR tree-optimization/117646
gcc/ChangeLog:
* match.pd (`max<a,b>==0`): Add casts to `unsigned type`.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/minmaxneeqptr-1.c: New test.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
Diff:
---
gcc/match.pd | 6 ++++--
gcc/testsuite/gcc.dg/torture/minmaxneeqptr-1.c | 21 +++++++++++++++++++++
2 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index 4bec24a21b29..f5181325f3b9 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -4799,9 +4799,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
MAX (A, B) != 0 -> (A|B) != 0 iff unsigned. */
(for cmp (eq ne)
(simplify
- (cmp (max @0 @1) integer_zerop@2)
+ (cmp (max @0 @1) integer_zerop)
(if (TYPE_UNSIGNED (TREE_TYPE (@0)))
- (cmp (bit_ior @0 @1) @2))))
+ (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); }
+ (cmp (bit_ior (convert:utype @0) (convert:utype @1))
+ { build_zero_cst (utype); } )))))
/* Undo fancy ways of writing max/min or other ?: expressions, like
a - ((a - b) & -(a < b)) and a - (a - b) * (a < b) into (a < b) ? b : a.
diff --git a/gcc/testsuite/gcc.dg/torture/minmaxneeqptr-1.c
b/gcc/testsuite/gcc.dg/torture/minmaxneeqptr-1.c
new file mode 100644
index 000000000000..aa45722330f4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/minmaxneeqptr-1.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+
+/* PR tree-optimization/117646 */
+
+int maxeq(char *a, char *b) {
+ char *p = a < b ? b : a;
+ return p == (void*)0;
+}
+int maxne(char *a, char *b) {
+ char *p = a < b ? b : a;
+ return p == (void*)0;
+}
+
+int mineq(char *a, char *b) {
+ char *p = a > b ? b : a;
+ return p == (void*)0;
+}
+int minne(char *a, char *b) {
+ char *p = a > b ? b : a;
+ return p == (void*)0;
+}
