tree-optimization/106513 - fix mistake in bswap symbolic number shifts
Commit Message
This fixes a mistake in typing a local variable in the symbolic
shift routine.
Bootstrap & regtest pending on x86_64-unknown-linux-gnu.
PR tree-optimization/106513
* gimple-ssa-store-merging.cc (do_shift_rotate): Use uint64_t
for head_marker.
* gcc.dg/torture/pr106513.c: New testcase.
---
gcc/gimple-ssa-store-merging.cc | 2 +-
gcc/testsuite/gcc.dg/torture/pr106513.c | 26 +++++++++++++++++++++++++
2 files changed, 27 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr106513.c
Comments
On Wed, Aug 10, 2022 at 03:47:10PM +0200, Richard Biener via Gcc-patches wrote:
> This fixes a mistake in typing a local variable in the symbolic
> shift routine.
>
> Bootstrap & regtest pending on x86_64-unknown-linux-gnu.
>
> PR tree-optimization/106513
> * gimple-ssa-store-merging.cc (do_shift_rotate): Use uint64_t
> for head_marker.
Ok.
>
> * gcc.dg/torture/pr106513.c: New testcase.
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/pr106513.c
> @@ -0,0 +1,26 @@
> +/* { dg-do run } */
> +
> +typedef __INT64_TYPE__ int64_t;
> +
> +__attribute__((noinline)) int64_t
> +swap64 (int64_t n)
> +{
> + return (((n & (((int64_t) 0xff) )) << 56) |
> + ((n & (((int64_t) 0xff) << 8)) << 40) |
> + ((n & (((int64_t) 0xff) << 16)) << 24) |
> + ((n & (((int64_t) 0xff) << 24)) << 8) |
> + ((n & (((int64_t) 0xff) << 32)) >> 8) |
> + ((n & (((int64_t) 0xff) << 40)) >> 24) |
> + ((n & (((int64_t) 0xff) << 48)) >> 40) |
> + ((n & ((int64_t)(0xffull << 56))) >> 56));
> +}
> +
> +int main (void)
> +{
> + volatile int64_t n = 0x8000000000000000l;
> +
> + if (swap64(n) != 0xffffffffffffff80l)
> + __builtin_abort ();
Please use ll instead of l in both cases above.
Perhaps -0x80ll would be simpler...
Jakub
@@ -263,7 +263,7 @@ do_shift_rotate (enum tree_code code,
int count)
{
int i, size = TYPE_PRECISION (n->type) / BITS_PER_UNIT;
- unsigned head_marker;
+ uint64_t head_marker;
if (count < 0
|| count >= TYPE_PRECISION (n->type)
new file mode 100644
@@ -0,0 +1,26 @@
+/* { dg-do run } */
+
+typedef __INT64_TYPE__ int64_t;
+
+__attribute__((noinline)) int64_t
+swap64 (int64_t n)
+{
+ return (((n & (((int64_t) 0xff) )) << 56) |
+ ((n & (((int64_t) 0xff) << 8)) << 40) |
+ ((n & (((int64_t) 0xff) << 16)) << 24) |
+ ((n & (((int64_t) 0xff) << 24)) << 8) |
+ ((n & (((int64_t) 0xff) << 32)) >> 8) |
+ ((n & (((int64_t) 0xff) << 40)) >> 24) |
+ ((n & (((int64_t) 0xff) << 48)) >> 40) |
+ ((n & ((int64_t)(0xffull << 56))) >> 56));
+}
+
+int main (void)
+{
+ volatile int64_t n = 0x8000000000000000l;
+
+ if (swap64(n) != 0xffffffffffffff80l)
+ __builtin_abort ();
+
+ return 0;
+}