hw/apic.c: use __builtin funtions instead of assembly code
Suggested by malc.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5465 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/hw/apic.c b/hw/apic.c
index 0f661b6..46daf8a 100644
--- a/hw/apic.c
+++ b/hw/apic.c
@@ -104,15 +104,14 @@
static void apic_set_irq(APICState *s, int vector_num, int trigger_mode);
static void apic_update_irq(APICState *s);
-/* Find first bit starting from msb. Return 0 if value = 0 */
+/* Find first bit starting from msb */
static int fls_bit(uint32_t value)
{
+#if defined(__GNUC__)
+ return 31 - __builtin_clz(value);
+#else
unsigned int ret = 0;
-#if defined(HOST_I386) || defined(HOST_X86_64)
- __asm__ __volatile__ ("bsr %1, %0\n" : "+r" (ret) : "rm" (value));
- return ret;
-#else
if (value > 0xffff)
value >>= 16, ret = 16;
if (value > 0xff)
@@ -125,15 +124,14 @@
#endif
}
-/* Find first bit starting from lsb. Return 0 if value = 0 */
+/* Find first bit starting from lsb */
static int ffs_bit(uint32_t value)
{
+#if defined(__GNUC__)
+ return __builtin_ffs(value) - 1;
+#else
unsigned int ret = 0;
-#if defined(HOST_I386) || defined(HOST_X86_64)
- __asm__ __volatile__ ("bsf %1, %0\n" : "+r" (ret) : "rm" (value));
- return ret;
-#else
if (!value)
return 0;
if (!(value & 0xffff))