Unverified Commit 79ba5c1c authored by Ignacio Encinas's avatar Ignacio Encinas Committed by Alexandre Ghiti
Browse files

selftests: riscv: fix v_exec_initval_nolibc.c 



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: default avatarCharlie Jenkins <charlie@rivosinc.com>
Tested-by: default avatarCharlie Jenkins <charlie@rivosinc.com>
Signed-off-by: default avatarIgnacio Encinas <ignacio@iencinas.com>
Link: https://lore.kernel.org/r/20250306-fix-v_exec_initval_nolibc-v2-1-97f9dc8a7faf@iencinas.com


Signed-off-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
parent 83d78ac6

tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c

+3 −7
Original line number Diff line number Diff line
@@ -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;						\

	}									\

})