https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118976
--- Comment #12 from Luke Robison <lrbison at amazon dot com> --- Tamar, I'm happy to test as many flags as you can think of, just send them my way. See below for detailed results, but I see that -fdisable-tree-cunroll does not fix the problem, and I suspect that -march=armv8.4-a+sve must cause a similar code path to -fno-vect-cost-model, since without a CPU to target, no cost model is available. In fact, with those flags, this problem affects gcc down to 8 as well. CFLAGS="-fno-inline -O3 -Wall -fno-strict-aliasing -march=armv8.4-a+sve " gcc:8 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 gcc:9 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 gcc:10 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 gcc:11 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 gcc:12.4 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 gcc:13.3 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 gcc:14.2 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 CFLAGS="-fno-inline -O3 -Wall -fno-strict-aliasing -march=armv8.4-a+sve -fdisable-tree-cunroll" cc1: note: disable pass tree-cunroll for functions in the range of [0, 4294967295] gcc:8 gives PASS: got 0x00bbbbbb 0x00aaaaaa as expected cc1: note: disable pass tree-cunroll for functions in the range of [0, 4294967295] gcc:9 gives PASS: got 0x00bbbbbb 0x00aaaaaa as expected cc1: note: disable pass tree-cunroll for functions in the range of [0, 4294967295] gcc:10 gives PASS: got 0x00bbbbbb 0x00aaaaaa as expected cc1: note: disable pass tree-cunroll for functions in the range of [0, 4294967295] gcc:11 gives PASS: got 0x00bbbbbb 0x00aaaaaa as expected cc1: note: disable pass tree-cunroll for functions in the range of [0, 4294967295] gcc:12.4 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 cc1: note: disable pass tree-cunroll for functions in the range of [0, 4294967295] gcc:13.3 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00 cc1: note: disable pass tree-cunroll for functions in the range of [0, 4294967295] gcc:14.2 gives ERROR: expected 0x00bbbbbb 0x00aaaaaa but got 0x00bbbbbb 0xaaaaaa00
