The switch conversion code will generate an array with VLA vector constants in
it
in some cases but this does not work as the length of the vector type is not
known
at compile time; only the min size is known.
I tried to reject this in initializer_constant_valid_p but code from the C++
front-end
will call initializer_constant_valid_p for `vector_arrayx4()` and then will
cause an ICE
with g++.target/aarch64/sve/pr116595.C (and
g++.target/riscv/rvv/autovec/pr116595.C).
Built and tested for aarch64-linux-gnu.
PR tree-optimization/121091
gcc/ChangeLog:
* tree-switch-conversion.cc (switch_conversion::check_final_bb): Reject
vector types which
have a non-constant number of elements.
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/sve/pr121091-1.c: New test.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
---
.../gcc.target/aarch64/sve/pr121091-1.c | 25 +++++++++++++++++++
gcc/tree-switch-conversion.cc | 3 +++
2 files changed, 28 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/aarch64/sve/pr121091-1.c
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pr121091-1.c
b/gcc/testsuite/gcc.target/aarch64/sve/pr121091-1.c
new file mode 100644
index 00000000000..ea2e5ce6b6a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/pr121091-1.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+/* PR tree-optimization/121091 */
+/* Switch conversion would convert this
+ into static constant array but since
+ svbool_t is a VLA type, it can't be
+ stored in a constant pool. */
+
+#include "arm_sve.h"
+
+svbool_t e(int mode, svbool_t pg) {
+ switch (mode) {
+ case 0:
+ pg = svptrue_pat_b16(SV_VL6);
+ break;
+ case 1:
+ pg = svpfalse_b();
+ break;
+ case 2:
+ pg = svptrue_pat_b16(SV_VL2);
+ break;
+ }
+ return pg;
+}
diff --git a/gcc/tree-switch-conversion.cc b/gcc/tree-switch-conversion.cc
index d0882879e61..dc9f67bd272 100644
--- a/gcc/tree-switch-conversion.cc
+++ b/gcc/tree-switch-conversion.cc
@@ -636,6 +636,9 @@ switch_conversion::check_final_bb ()
val = gimple_phi_arg_def (phi, i);
if (!is_gimple_ip_invariant (val))
reason = "non-invariant value from a case";
+ else if (VECTOR_TYPE_P (TREE_TYPE (val))
+ && !TYPE_VECTOR_SUBPARTS (TREE_TYPE (val)).is_constant
())
+ reason = "VLA vector type";
else
{
reloc = initializer_constant_valid_p (val, TREE_TYPE (val));
--
2.43.0
