On 24/06/2024 8:29 am, Xin Li wrote:
On 6/23/2024 1:28 PM, Brian Gerst wrote:
On Sat, Jun 22, 2024 at 1:14 PM Xin Li (Intel) <xin@xxxxxxxxx> wrote:
- printf "#define %s_MASK_CHECK
BUILD_BUG_ON_ZERO(NCAPINTS != %d)\n\n", s, ncapints;
+ printf "\n#define %s_FEATURE(x)\t\t\t\t\\\n", s;
+ printf "\t((\t\t\t\t\t";
+ for (i = 0; i < ncapints; i++) {
+ if (masks[i])
+ printf "\t\\\n\t\t((x) >> 5) == %2d
? %s_MASK%d :", i, s, i;
+ }
+ printf " 0\t\\\n";
+ printf "\t) & (1 << ((x) & 31)))\n";
The original macro had 1UL here. I don't know if it is strictly
necessary in this case since we're using 32-bit masks, but it would
probably be safer.
I did notice it, but don't think UL is needed.
You do need 1U, or you'll trip UBSAN every time you test feature 31 in a
word.
I'll note that the hypervisor bit is one such example.