| Message ID | 20231012215903.2104652-1-visitorckw@gmail.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | ACPI: NFIT: Optimize nfit_mem_cmp() for efficiency | expand |
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index f96bf32cd368..eea827d9af08 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1138,11 +1138,7 @@ static int nfit_mem_cmp(void *priv, const struct list_head *_a, handleA = __to_nfit_memdev(a)->device_handle; handleB = __to_nfit_memdev(b)->device_handle; - if (handleA < handleB) - return -1; - else if (handleA > handleB) - return 1; - return 0; + return handleA - handleB; } static int nfit_mem_init(struct acpi_nfit_desc *acpi_desc)
The original code used conditional branching in the nfit_mem_cmp function to compare two values and return -1, 1, or 0 based on the result. However, the list_sort comparison function only needs results <0, >0, or =0. This patch optimizes the code to make the comparison branchless, improving efficiency and reducing code size. This change reduces the number of comparison operations from 1-2 to a single subtraction operation, thereby saving the number of instructions. Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> --- drivers/acpi/nfit/core.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)