Cleanup: remove unused m4/libxml.m4

[lttng-tools.git] / src / common / utils.c

diff --git a/src/common/utils.c b/src/common/utils.c
index 16d2f817ad8a1b21d99228a67e5bba25e0d1f3fa..893122905bd44ca75b9fa3836cdf9098e142dfff 100644 (file)
--- 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.
@@ -1362,11 +1429,17 @@ static const char *get_man_bin_path(void)
 }
 
 LTTNG_HIDDEN
-int utils_show_man_page(int section, const char *page_name)
+int utils_show_help(int section, const char *page_name,
+               const char *help_msg)
 {
        char section_string[8];
        const char *man_bin_path = get_man_bin_path();
-       int ret;
+       int ret = 0;
+
+       if (help_msg) {
+               printf("%s", help_msg);
+               goto end;
+       }
 
        /* Section integer -> section string */
        ret = sprintf(section_string, "%d", section);
@@ -1381,5 +1454,7 @@ int utils_show_man_page(int section, const char *page_name)
         */
        ret = execlp(man_bin_path, "man", "-M", MANPATH,
                section_string, page_name, NULL);
+
+end:
        return ret;
 }