X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=4d49728c0f47a23cce6eba1bc2f72f11c2c14836;hb=cf0bcb51ea857687a353d2851e572dba6cc63cb0;hp=16d2f817ad8a1b21d99228a67e5bba25e0d1f3fa;hpb=b07e7ef09b90a6bbb055f49bb2a6586dd45e73c9;p=lttng-tools.git

diff --git a/src/common/utils.c b/src/common/utils.c
index 16d2f817a..4d49728c0 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -1017,6 +1017,59 @@ static inline unsigned int fls_u32(uint32_t x)
 #define HAS_FLS_U32
 #endif
 
+#if defined(__x86_64)
+static inline
+unsigned int fls_u64(uint64_t x)
+{
+	long r;
+
+	asm("bsrq %1,%0\n\t"
+	    "jnz 1f\n\t"
+	    "movq $-1,%0\n\t"
+	    "1:\n\t"
+	    : "=r" (r) : "rm" (x));
+	return r + 1;
+}
+#define HAS_FLS_U64
+#endif
+
+#ifndef HAS_FLS_U64
+static __attribute__((unused))
+unsigned int fls_u64(uint64_t x)
+{
+	unsigned int r = 64;
+
+	if (!x)
+		return 0;
+
+	if (!(x & 0xFFFFFFFF00000000ULL)) {
+		x <<= 32;
+		r -= 32;
+	}
+	if (!(x & 0xFFFF000000000000ULL)) {
+		x <<= 16;
+		r -= 16;
+	}
+	if (!(x & 0xFF00000000000000ULL)) {
+		x <<= 8;
+		r -= 8;
+	}
+	if (!(x & 0xF000000000000000ULL)) {
+		x <<= 4;
+		r -= 4;
+	}
+	if (!(x & 0xC000000000000000ULL)) {
+		x <<= 2;
+		r -= 2;
+	}
+	if (!(x & 0x8000000000000000ULL)) {
+		x <<= 1;
+		r -= 1;
+	}
+	return r;
+}
+#endif
+
 #ifndef HAS_FLS_U32
 static __attribute__((unused)) unsigned int fls_u32(uint32_t x)
 {
@@ -1063,6 +1116,20 @@ int utils_get_count_order_u32(uint32_t x)
 	return fls_u32(x - 1);
 }
 
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+LTTNG_HIDDEN
+int utils_get_count_order_u64(uint64_t x)
+{
+	if (!x) {
+		return -1;
+	}
+
+	return fls_u64(x - 1);
+}
+
 /**
  * Obtain the value of LTTNG_HOME environment variable, if exists.
  * Otherwise returns the value of HOME.