util/cutils: Introduce freq_to_str() to display Hertz units

Introduce freq_to_str() to convert frequency values in human
friendly units using the SI units for Hertz.

Suggested-by: Luc Michel <luc@lmichel.fr>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Message-Id: <20201012095804.3335117-2-f4bug@amsat.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/util/cutils.c b/util/cutils.c
index 8da34e04b0..be4e43a9ef 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -885,6 +885,20 @@ char *size_to_str(uint64_t val)
     return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
 }
 
+char *freq_to_str(uint64_t freq_hz)
+{
+    static const char *const suffixes[] = { "", "K", "M", "G", "T", "P", "E" };
+    double freq = freq_hz;
+    size_t idx = 0;
+
+    while (freq >= 1000.0 && idx < ARRAY_SIZE(suffixes)) {
+        freq /= 1000.0;
+        idx++;
+    }
+
+    return g_strdup_printf("%0.3g %sHz", freq, suffixes[idx]);
+}
+
 int qemu_pstrcmp0(const char **str1, const char **str2)
 {
     return g_strcmp0(*str1, *str2);