Created
August 1, 2016 06:50
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FP magic with 32-bit
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import std.stdio; | |
alias S = float; | |
float shL = 0x1.1b95eep-4; // -0.069235 | |
float shR = 0x1.9c7cfep-7; // -0.012588 | |
F fun(F)(F x) | |
{ | |
return 1.0 + x * 2; | |
} | |
S f1() | |
{ | |
S r = fun(shR); | |
S l = fun(shL); | |
return (r - l); | |
} | |
S f2() | |
{ | |
return (fun(shR) - fun(shL)); | |
} | |
unittest | |
{ | |
writefln("f1: %a", f1()); | |
writefln("f2: %a", f2()); | |
assert(f1 == f2); // fails on 32-bit | |
} |
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f1: -0x1.d00cap-4 | |
f2: -0x1.d00c9cp-4 | |
core.exception.AssertError@en.d(28): unittest failure |
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