Correct ilogb(0)

4 files changed, 27 insertions, 4 deletions

diff --git a/test.cc b/test.cc
index 818b23a..86078c5 100644
--- a/test.cc
+++ b/test.cc
@@ -371,7 +371,13 @@ struct vecmathlib_test {
   }
   
   // Change signature: "int" -> "int_t"
-  static int_t ilogb(real_t x) { return std::ilogb(x); }
+  static int_t ilogb(real_t x)
+  {
+    int r = std::ilogb(x);
+    if (r==FP_ILOGB0) return numeric_limits<int_t>::min();
+    if (r==FP_ILOGBNAN) return numeric_limits<int_t>::max();
+    return r;
+  }
   static real_t ldexp(real_t x, int_t n) { return std::ldexp(x, n); }
   static void test_fabs()
   {
diff --git a/vec_double_sse2_scalar.h b/vec_double_sse2_scalar.h
index 70f94e1..66b1398 100644
--- a/vec_double_sse2_scalar.h
+++ b/vec_double_sse2_scalar.h
@@ -396,7 +396,13 @@ namespace vecmathlib {
     }
     realvec fmod(realvec y) const { return std::fmod(v, y.v); }
     realvec hypot(realvec y) const { return MF::vml_hypot(*this, y); }
-    intvec_t ilogb() const { return std::ilogb(v); }
+    intvec_t ilogb() const
+    {
+      int_t r = std::ilogb(v);
+      if (r == FP_ILOGB0) r = numeric_limits<int_t>::min();
+      else if (r == FP_ILOGBNAN) r = numeric_limits<int_t>::max();
+      return r;
+    }
     boolvec_t isfinite() const { return std::isfinite(v); }
     boolvec_t isinf() const { return std::isinf(v); }
     boolvec_t isnan() const { return std::isnan(v); }
diff --git a/vec_float_sse2_scalar.h b/vec_float_sse2_scalar.h
index e39a324..def48fa 100644
--- a/vec_float_sse2_scalar.h
+++ b/vec_float_sse2_scalar.h
@@ -396,7 +396,13 @@ namespace vecmathlib {
     }
     realvec fmod(realvec y) const { return std::fmod(v, y.v); }
     realvec hypot(realvec y) const { return MF::vml_hypot(*this, y); }
-    intvec_t ilogb() const { return std::ilogb(v); }
+    intvec_t ilogb() const
+    {
+      int_t r = std::ilogb(v);
+      if (r == FP_ILOGB0) r = numeric_limits<int_t>::min();
+      else if (r == FP_ILOGBNAN) r = numeric_limits<int_t>::max();
+      return r;
+    }
     boolvec_t isfinite() const { return std::isfinite(v); }
     boolvec_t isinf() const { return std::isinf(v); }
     boolvec_t isnan() const { return std::isnan(v); }
diff --git a/vec_pseudo.h b/vec_pseudo.h
index 31d9cbb..ad3a70c 100644
--- a/vec_pseudo.h
+++ b/vec_pseudo.h
@@ -680,7 +680,12 @@ namespace vecmathlib {
     intvec_t ilogb() const
     {
       intvec_t res;
-      for (int d=0; d<size; ++d) res.v[d] = std::ilogb(v[d]);
+      for (int d=0; d<size; ++d) {
+        int_t r = std::ilogb(v[d]);
+        if (r == FP_ILOGB0) r = numeric_limits<int_t>::min();
+        else if (r == FP_ILOGBNAN) r = numeric_limits<int_t>::max();
+        res.v[d] = r;
+      }
       return res;
     }
     boolvec_t isfinite() const { return mapb(std::isfinite); }