Vector registers are zero initialized by the kernel. Stop accepting "all ones" as a clean value.

Note that this was not working as expected given that value == 0xff can be assumed to be always false by the compiler as value's range is [-128, 127]. Both GCC (-Wtype-limits) and clang (-Wtautological-constant-out-of-range-compare) warn about this.

Reviewed-by: Charlie Jenkins charlie@rivosinc.com Tested-by: Charlie Jenkins charlie@rivosinc.com Signed-off-by: Ignacio Encinas ignacio@iencinas.com --- Changes in v2:

Remove code that becomes useless now that the only "clean" value for vector registers is 0.

- Link to v1: https://lore.kernel.org/r/20250305-fix-v_exec_initval_nolibc-v1-1-b87b60e430... --- tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c b/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c index 35c0812e32de0c82a54f84bd52c4272507121e35..4dde05e45a04122b566cedc36d20b072413b00e2 100644 --- a/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c +++ b/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c @@ -6,7 +6,7 @@ * the values. To further ensure consistency, this file is compiled without * libc and without auto-vectorization. * - * To be "clean" all values must be either all ones or all zeroes. + * To be "clean" all values must be all zeroes. */

#define __stringify_1(x...) #x @@ -14,9 +14,8 @@

int main(int argc, char **argv) { - char prev_value = 0, value; + char value = 0; unsigned long vl; - int first = 1;

if (argc > 2 && strcmp(argv[2], "x")) asm volatile ( @@ -44,14 +43,11 @@ int main(int argc, char **argv) "vsrl.vi " __stringify(register) ", " __stringify(register) ", 8\n\t" \ ".option pop\n\t" \ : "=r" (value)); \ - if (first) { \ - first = 0; \ - } else if (value != prev_value || !(value == 0x00 || value == 0xff)) { \ + if (value != 0x00) { \ printf("Register " __stringify(register) \ " values not clean! value: %u\n", value); \ exit(-1); \ } \ - prev_value = value; \ } \ })

--- base-commit: 03d38806a902b36bf364cae8de6f1183c0a35a67 change-id: 20250301-fix-v_exec_initval_nolibc-498d976c372d

Best regards,