The comment above expand_vector_broadcast() states a precondition that
the mode of op must be the element mode of vmode. But when
expand_binop() called expand_vector_broadcast() to broadcast the shift
amount, it only truncated the shift amount if it's too wide, but no
action is performed if the shift amount is too narrow.
PR middle-end/124250
PR target/123807
gcc/
* optabs.cc (expand_vector_broadcast): Add a checking assert to
verify the precondition about the input modes.
(expand_binop): Extend the shift amount if it's narrower than
the element of the shifted vector.
gcc/testsuite/
* gcc.c-torture/compile/pr124250.c: New test.
---
Bootstrapped and regtested on x86_64-linux-gnu and
loongarch64-linux-gnu. Ok for trunk?
gcc/optabs.cc | 34 +++++++++++++------
.../gcc.c-torture/compile/pr124250.c | 8 +++++
2 files changed, 31 insertions(+), 11 deletions(-)
create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr124250.c
diff --git a/gcc/optabs.cc b/gcc/optabs.cc
index e813cf9b215..249413c7576 100644
--- a/gcc/optabs.cc
+++ b/gcc/optabs.cc
@@ -428,9 +428,9 @@ force_expand_binop (machine_mode mode, optab binoptab,
return true;
}
-/* Create a new vector value in VMODE with all elements set to OP. The
- mode of OP must be the element mode of VMODE. If OP is a constant,
- then the return value will be a constant. */
+/* Create a new vector value in VMODE with all elements set to OP. If OP
+ is not a constant, the mode of it must be the element mode of VMODE.
+ If OP is a constant, then the return value will be a constant. */
rtx
expand_vector_broadcast (machine_mode vmode, rtx op)
@@ -439,6 +439,8 @@ expand_vector_broadcast (machine_mode vmode, rtx op)
rtvec vec;
gcc_checking_assert (VECTOR_MODE_P (vmode));
+ gcc_checking_assert (CONST_INT_P (op)
+ || GET_MODE_INNER (vmode) == GET_MODE (op));
if (valid_for_const_vector_p (vmode, op))
return gen_const_vec_duplicate (vmode, op);
@@ -1629,15 +1631,25 @@ expand_binop (machine_mode mode, optab binoptab, rtx
op0, rtx op1,
if (otheroptab
&& (icode = optab_handler (otheroptab, mode)) != CODE_FOR_nothing)
{
- /* The scalar may have been extended to be too wide. Truncate
- it back to the proper size to fit in the broadcast vector. */
+ /* The scalar may be wider or narrower than the vector element.
+ Truncate or extend it to the proper size to fit in the
+ broadcast vector. */
scalar_mode inner_mode = GET_MODE_INNER (mode);
- if (!CONST_INT_P (op1)
- && (GET_MODE_BITSIZE (as_a <scalar_int_mode> (GET_MODE (op1)))
- > GET_MODE_BITSIZE (inner_mode)))
- op1 = force_reg (inner_mode,
- simplify_gen_unary (TRUNCATE, inner_mode, op1,
- GET_MODE (op1)));
+ if (!CONST_INT_P (op1))
+ {
+ auto mode1 = as_a <scalar_int_mode> (GET_MODE (op1));
+ int size1 = GET_MODE_BITSIZE (mode1);
+ int inner_size = GET_MODE_BITSIZE (inner_mode);
+
+ if (size1 != inner_size)
+ {
+ auto unary = size1 > inner_size ? TRUNCATE : ZERO_EXTEND;
+ op1 = force_reg (inner_mode,
+ simplify_gen_unary (unary, inner_mode,
+ op1, mode1));
+ }
+ }
+
rtx vop1 = expand_vector_broadcast (mode, op1);
if (vop1)
{
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr124250.c
b/gcc/testsuite/gcc.c-torture/compile/pr124250.c
new file mode 100644
index 00000000000..1435091dc0b
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr124250.c
@@ -0,0 +1,8 @@
+typedef long long v2i64 __attribute__ ((vector_size (16), aligned (16)));
+v2i64 a, b;
+
+void
+test (int l)
+{
+ a = b >> (-l);
+}
--
2.53.0
