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+/// Copyright (c) 2012 Ecma International. All rights reserved.
+/// Ecma International makes this code available under the terms and conditions set
+/// forth on http://hg.ecmascript.org/tests/test262/raw-file/tip/LICENSE (the
+/// "Use Terms"). Any redistribution of this code must retain the above
+/// copyright and this notice and otherwise comply with the Use Terms.
+/**
+ * @path ch08/8.5/8.5.1.js
+ * @description Valid Number ranges
+ */
+
+// Check range support for Number values (IEEE 754 64-bit floats having the form s*m*2**e)
+//
+// For normalized floats, sign (s) is +1 or -1, m (mantisa) is a positive integer less
+// than 2**53 but not less than 2**52 and e (exponent) is an integer ranging from -1074 to 971
+//
+// For denormalized floats, s is +1 or -1, m is a positive integer less than 2**52, and
+// e is -1074
+//
+// Below 64-bit float values shown for informational purposes. Values may be positive or negative.
+// Infinity >= ~1.797693134862315907729305190789e+308 >= 2**1024
+// MAX_NORM = ~1.797693134862315708145274237317e+308 = (2**53 - 1) * (2**-52) * (2**1023) = (2**53-1) * (2**971) = (2**1024) - (2**971)
+// MIN_NORM = ~2.2250738585072013830902327173324e-308 = 2**-1022
+// MAX_DENORM = ~2.2250738585072008890245868760859e-308 = MIN_NORM - MIN_DENORM = (2**-1022) - (2**-1074)
+// MIN_DENORM = ~4.9406564584124654417656879286822e-324 = 2**-1074
+
+// Fill an array with 2 to the power of (0 ... -1075)
+var value = 1;
+var floatValues = new Array(1076);
+for(var power = 0; power <= 1075; power++){
+ floatValues[power] = value;
+ // Use basic math operations for testing, which are required to support 'gradual underflow' rather
+ // than Math.pow etc..., which are defined as 'implementation dependent'.
+ value = value * 0.5;
+}
+
+// The last value is below min denorm and should round to 0, everything else should contain a value
+if(floatValues[1075] !== 0) {
+ $ERROR("Value after min denorm should round to 0");
+}
+
+// Validate the last actual value is min denorm
+if(floatValues[1074] !== 4.9406564584124654417656879286822e-324) {
+ $ERROR("Min denorm value is incorrect: " + floatValues[1074]);
+}
+
+// Validate that every value is half the value before it up to 1
+for(var index = 1074; index > 0; index--){
+ if(floatValues[index] === 0){
+ $ERROR("2**-" + index + " should not be 0");
+ }
+ if(floatValues[index - 1] !== (floatValues[index] * 2)){
+ $ERROR("Value should be double adjacent value at index " + index);
+ }
+}
+
+// Max norm should be supported and compare less than inifity
+if(!(1.797693134862315708145274237317e+308 < Infinity)){
+ $ERROR("Max Number value 1.797693134862315708145274237317e+308 should not overflow to infinity");
+}
+
+// Numbers closer to 2**1024 then max norm should overflow to infinity
+if(!(1.797693134862315808e+308 === +Infinity)){
+ $ERROR("1.797693134862315808e+308 did not resolve to Infinity");
+}