[COMMITTED] match: Improve `(a != b) ? (a + b) : (2 * a)` pattern [PR19832]
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Commit Message
In the testcase provided, we would match f_plus but not g_plus
due to a missing `:c` on the plus operator. This fixes the oversight
there.
Note this was noted in https://github.com/llvm/llvm-project/issues/76318 .
Committed as obvious after bootstrap/test on x86_64-linux-gnu.
PR tree-optimization/19832
gcc/ChangeLog:
* match.pd (`(a != b) ? (a + b) : (2 * a)`): Add `:c`
on the plus operator.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/phi-opt-same-2.c: New test.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
---
gcc/match.pd | 2 +-
.../gcc.dg/tree-ssa/phi-opt-same-2.c | 19 +++++++++++++++++++
2 files changed, 20 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-same-2.c
@@ -5694,7 +5694,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
@2)))
/* (a != b) ? (a + b) : (2 * a) -> (a + b) */
(simplify
- (cnd (ne:c @0 @1) (plus@2 @0 @1) (mult @0 uniform_integer_cst_p@3))
+ (cnd (ne:c @0 @1) (plus:c@2 @0 @1) (mult @0 uniform_integer_cst_p@3))
(if (wi::to_wide (uniform_integer_cst_p (@3)) == 2)
@2))
)
new file mode 100644
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-phiopt1 -fdump-tree-optimized" } */
+/* PR tree-optimization/19832 */
+
+int f_plus(int a, int b)
+{
+ if (a != b) return a + b;
+ return a + a;
+}
+
+int g_plus(int a, int b)
+{
+ if (b != a) return a + b;
+ return a + a;
+}
+
+/* All of the above function's if should have been optimized away even in phiopt1. */
+/* { dg-final { scan-tree-dump-not "if " "phiopt1" } } */
+/* { dg-final { scan-tree-dump-not "if " "optimized" } } */