benchtests: Add ilogb* tests

Add a benchtest to ilogb, ilogbf and ilogbf128 based on the logb* benchtests.

benchtests/Makefile

@@ -25,10 +25,10 @@ bench-math := acos acosh asin asinh atan atanh cos cosh exp exp2 log log2 \
 	      modf pow rint sin sincos sinh sqrt tan tanh fmin fmax fminf \
 	      fmaxf powf trunc truncf roundeven roundevenf expf exp2f logf \
 	      log2f sincosf sinf cosf isnan isinf isfinite hypot logb logbf \
-	      exp10f
+	      exp10f ilogb ilogbf
 
 ifneq (,$(filter yes,$(float128-fcts) $(float128-alias-fcts)))
-bench-math += expf128 powf128 sinf128
+bench-math += expf128 powf128 sinf128 ilogbf128
 endif
 
 bench-pthread := pthread_once thread_create pthread-locks

benchtests/ilogb-inputs

@@ -0,0 +1,11 @@
+## args: double
+## ret: int
+## includes: math.h
+
+## name: subnormal
+0x0.0000000000001p-1022
+0x0.fffffffffffffp-1022
+
+## name: normal
+1.0
+1024.0

benchtests/ilogbf-inputs

@@ -0,0 +1,11 @@
+## args: float
+## ret: int
+## includes: math.h
+
+## name: subnormal
+0x1p-149
+0x1.fffff8p-128
+
+## name: normal
+1.0
+1024.0

benchtests/ilogbf128-inputs

@@ -0,0 +1,11 @@
+## args: _Float128
+## ret: int
+## includes: math.h
+
+## name: subnormal
+6.47517511943802511092443895822764655e-4966f128
+0x1.fffffffffffffff8p-16383f128
+
+## name: normal
+1.0
+-0x8.2faf442f390a9211f5af128673fp+0L