core.math: Use internal approxEqual to allow some inaccuracies on certain hardware

Author: ibuclaw

src/core/math.d

@@ -221,26 +221,32 @@ T toPrec(T:real)(real f)  { pragma(inline, false); return f; }
     r = toPrec!real(d + d);
     r = toPrec!real(r + r);
 
+    // Comparison tests.
+    bool approxEqual(T)(T lhs, T rhs)
+    {
+        return fabs((lhs - rhs) / rhs) <= 1e-2 || fabs(lhs - rhs) <= 1e-5;
+    }
+
     enum real PIR = 0xc.90fdaa22168c235p-2;
     enum double PID = 0x1.921fb54442d18p+1;
     enum float PIF = 0x1.921fb6p+1;
-    static assert(toPrec!float(PIR) == PIF);
-    static assert(toPrec!double(PIR) == PID);
-    static assert(toPrec!real(PIR) == PIR);
-    static assert(toPrec!float(PID) == PIF);
-    static assert(toPrec!double(PID) == PID);
-    static assert(toPrec!real(PID) == PID);
-    static assert(toPrec!float(PIF) == PIF);
-    static assert(toPrec!double(PIF) == PIF);
-    static assert(toPrec!real(PIF) == PIF);
-
-    assert(toPrec!float(PIR) == PIF);
-    assert(toPrec!double(PIR) == PID);
-    assert(toPrec!real(PIR) == PIR);
-    assert(toPrec!float(PID) == PIF);
-    assert(toPrec!double(PID) == PID);
-    assert(toPrec!real(PID) == PID);
-    assert(toPrec!float(PIF) == PIF);
-    assert(toPrec!double(PIF) == PIF);
-    assert(toPrec!real(PIF) == PIF);
+    static assert(approxEqual(toPrec!float(PIR), PIF));
+    static assert(approxEqual(toPrec!double(PIR), PID));
+    static assert(approxEqual(toPrec!real(PIR), PIR));
+    static assert(approxEqual(toPrec!float(PID), PIF));
+    static assert(approxEqual(toPrec!double(PID), PID));
+    static assert(approxEqual(toPrec!real(PID), PID));
+    static assert(approxEqual(toPrec!float(PIF), PIF));
+    static assert(approxEqual(toPrec!double(PIF), PIF));
+    static assert(approxEqual(toPrec!real(PIF), PIF));
+
+    assert(approxEqual(toPrec!float(PIR), PIF));
+    assert(approxEqual(toPrec!double(PIR), PID));
+    assert(approxEqual(toPrec!real(PIR), PIR));
+    assert(approxEqual(toPrec!float(PID), PIF));
+    assert(approxEqual(toPrec!double(PID), PID));
+    assert(approxEqual(toPrec!real(PID), PID));
+    assert(approxEqual(toPrec!float(PIF), PIF));
+    assert(approxEqual(toPrec!double(PIF), PIF));
+    assert(approxEqual(toPrec!real(PIF), PIF));
 }