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Diffstat (limited to 'compiler-rt/lib/builtins/clzsi2.c')
-rw-r--r--compiler-rt/lib/builtins/clzsi2.c62
1 files changed, 30 insertions, 32 deletions
diff --git a/compiler-rt/lib/builtins/clzsi2.c b/compiler-rt/lib/builtins/clzsi2.c
index fe06f065b00..90dc82d08ef 100644
--- a/compiler-rt/lib/builtins/clzsi2.c
+++ b/compiler-rt/lib/builtins/clzsi2.c
@@ -17,36 +17,34 @@
/* Precondition: a != 0 */
-COMPILER_RT_ABI si_int
-__clzsi2(si_int a)
-{
- su_int x = (su_int)a;
- si_int t = ((x & 0xFFFF0000) == 0) << 4; /* if (x is small) t = 16 else 0 */
- x >>= 16 - t; /* x = [0 - 0xFFFF] */
- su_int r = t; /* r = [0, 16] */
- /* return r + clz(x) */
- t = ((x & 0xFF00) == 0) << 3;
- x >>= 8 - t; /* x = [0 - 0xFF] */
- r += t; /* r = [0, 8, 16, 24] */
- /* return r + clz(x) */
- t = ((x & 0xF0) == 0) << 2;
- x >>= 4 - t; /* x = [0 - 0xF] */
- r += t; /* r = [0, 4, 8, 12, 16, 20, 24, 28] */
- /* return r + clz(x) */
- t = ((x & 0xC) == 0) << 1;
- x >>= 2 - t; /* x = [0 - 3] */
- r += t; /* r = [0 - 30] and is even */
- /* return r + clz(x) */
-/* switch (x)
- * {
- * case 0:
- * return r + 2;
- * case 1:
- * return r + 1;
- * case 2:
- * case 3:
- * return r;
- * }
- */
- return r + ((2 - x) & -((x & 2) == 0));
+COMPILER_RT_ABI si_int __clzsi2(si_int a) {
+ su_int x = (su_int)a;
+ si_int t = ((x & 0xFFFF0000) == 0) << 4; /* if (x is small) t = 16 else 0 */
+ x >>= 16 - t; /* x = [0 - 0xFFFF] */
+ su_int r = t; /* r = [0, 16] */
+ /* return r + clz(x) */
+ t = ((x & 0xFF00) == 0) << 3;
+ x >>= 8 - t; /* x = [0 - 0xFF] */
+ r += t; /* r = [0, 8, 16, 24] */
+ /* return r + clz(x) */
+ t = ((x & 0xF0) == 0) << 2;
+ x >>= 4 - t; /* x = [0 - 0xF] */
+ r += t; /* r = [0, 4, 8, 12, 16, 20, 24, 28] */
+ /* return r + clz(x) */
+ t = ((x & 0xC) == 0) << 1;
+ x >>= 2 - t; /* x = [0 - 3] */
+ r += t; /* r = [0 - 30] and is even */
+ /* return r + clz(x) */
+ /* switch (x)
+ * {
+ * case 0:
+ * return r + 2;
+ * case 1:
+ * return r + 1;
+ * case 2:
+ * case 3:
+ * return r;
+ * }
+ */
+ return r + ((2 - x) & -((x & 2) == 0));
}
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