Float (signed) number comparisons compiled to unsigned version of instruction

Why does

    public bool lteq(float a, float b) {
        return a <= b;
    }

    public bool lteq(float a, float b) {
        return a <= b;
    }

compile to

        IL_0000: ldarg.1
        IL_0001: ldarg.2
        IL_0002: cgt.un
        IL_0004: ldc.i4.0
        IL_0005: ceq
        IL_0007: ret

        IL_0000: ldarg.1
        IL_0001: ldarg.2
        IL_0002: cgt.un
        IL_0004: ldc.i4.0
        IL_0005: ceq
        IL_0007: ret

whereas

    public bool not(float a, float b) {
        return !(a > b);
    }

    public bool not(float a, float b) {
        return !(a > b);
    }

compiles to the same thing but with

cgt

cgt

instead of

cgt.un

cgt.un

? Are these two expressions not equivalent? I'm also confused why it's using

.un

.un

C#/VB/F# compiler playground.

C#•2y ago•

4 replies

Why does

    public bool lteq(float a, float b) {
        return a <= b;
    }

    public bool lteq(float a, float b) {
        return a <= b;
    }

compile to

        IL_0000: ldarg.1
        IL_0001: ldarg.2
        IL_0002: cgt.un
        IL_0004: ldc.i4.0
        IL_0005: ceq
        IL_0007: ret

        IL_0000: ldarg.1
        IL_0001: ldarg.2
        IL_0002: cgt.un
        IL_0004: ldc.i4.0
        IL_0005: ceq
        IL_0007: ret

whereas

    public bool not(float a, float b) {
        return !(a > b);
    }

    public bool not(float a, float b) {
        return !(a > b);
    }

compiles to the same thing but with

cgt

cgt

instead of

cgt.un

cgt.un

? Are these two expressions not equivalent? I'm also confused why it's using

.un

.un

C#/VB/F# compiler playground.