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authortmk <nobody@nowhere>2013-02-16 04:20:01 +0900
committertmk <nobody@nowhere>2013-02-16 04:20:01 +0900
commit998dc6c17e0b0cfe8377529a130d9c61590caf2a (patch)
treef0745fb55e970f057a862732739be4a665cdf910 /common/util.c
parentf8d289e66965f99469292370c3b9200a03254f8e (diff)
parent06e4fc66edd15efa5afdcaed2102c7698b626484 (diff)
Merge branch 'layer_switch'
Diffstat (limited to 'common/util.c')
-rw-r--r--common/util.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/common/util.c b/common/util.c
index 9d8fb93219..ff1926d7d1 100644
--- a/common/util.c
+++ b/common/util.c
@@ -39,6 +39,7 @@ uint8_t bitpop16(uint16_t bits)
}
// most significant on-bit - return highest location of on-bit
+// NOTE: return 0 when bit0 is on or all bits are off
uint8_t biton(uint8_t bits)
{
uint8_t n = 0;
@@ -47,3 +48,13 @@ uint8_t biton(uint8_t bits)
if (bits >> 1) { bits >>= 1; n += 1;}
return n;
}
+
+uint8_t biton16(uint16_t bits)
+{
+ uint8_t n = 0;
+ if (bits >> 8) { bits >>= 8; n += 8;}
+ if (bits >> 4) { bits >>= 4; n += 4;}
+ if (bits >> 2) { bits >>= 2; n += 2;}
+ if (bits >> 1) { bits >>= 1; n += 1;}
+ return n;
+}