Index: fusl/src/math/ilogbl.c |
diff --git a/fusl/src/math/ilogbl.c b/fusl/src/math/ilogbl.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..7b1a9cf8d007ff16c1d6fe072916a5a8a226e3e3 |
--- /dev/null |
+++ b/fusl/src/math/ilogbl.c |
@@ -0,0 +1,55 @@ |
+#include <limits.h> |
+#include "libm.h" |
+ |
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 |
+int ilogbl(long double x) |
+{ |
+ return ilogb(x); |
+} |
+#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 |
+int ilogbl(long double x) |
+{ |
+ #pragma STDC FENV_ACCESS ON |
+ union ldshape u = {x}; |
+ uint64_t m = u.i.m; |
+ int e = u.i.se & 0x7fff; |
+ |
+ if (!e) { |
+ if (m == 0) { |
+ FORCE_EVAL(0/0.0f); |
+ return FP_ILOGB0; |
+ } |
+ /* subnormal x */ |
+ for (e = -0x3fff+1; m>>63 == 0; e--, m<<=1); |
+ return e; |
+ } |
+ if (e == 0x7fff) { |
+ FORCE_EVAL(0/0.0f); |
+ return m<<1 ? FP_ILOGBNAN : INT_MAX; |
+ } |
+ return e - 0x3fff; |
+} |
+#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 |
+int ilogbl(long double x) |
+{ |
+ #pragma STDC FENV_ACCESS ON |
+ union ldshape u = {x}; |
+ int e = u.i.se & 0x7fff; |
+ |
+ if (!e) { |
+ if (x == 0) { |
+ FORCE_EVAL(0/0.0f); |
+ return FP_ILOGB0; |
+ } |
+ /* subnormal x */ |
+ x *= 0x1p120; |
+ return ilogbl(x) - 120; |
+ } |
+ if (e == 0x7fff) { |
+ FORCE_EVAL(0/0.0f); |
+ u.i.se = 0; |
+ return u.f ? FP_ILOGBNAN : INT_MAX; |
+ } |
+ return e - 0x3fff; |
+} |
+#endif |