Another shot at fixing the issues with (constant) struct literals and their addresses. See DMD2682, #218, #324. The idea is to separate the notion of const from 'this variable can always be replaced with its initializer' in the frontend. To do that, I introduced Declaration::isSameAsInitializer, which is overridden in VarDeclaration to return false for constants that have a struct literal initializer. So {{{ const S s = S(5); void foo() { auto ps = &s; } // is no longer replaced by void foo() { auto ps = &(S(5)); } }}} To make taking the address of a struct constant with a struct-initializer outside of function scope possible, I made sure that AddrExp::optimize doesn't try to run the argument's optimization with WANTinterpret - that'd again replace the constant with a struct literal temporary.

import ldc.intrinsics;

extern(C) int printf(char*,...);
extern(C) int scanf(char*,...);

void main()
{
    float f;
    printf("Enter float: ");
    //scanf("%f", &f);
    f = 1.22345;
    float sf = llvm_sqrt(f);
    printf("sqrt(%f) = %f\n", f, sf);

    double d;
    printf("Enter double: ");
    //scanf("%lf", &d);
    d = 2.2311167895435245;
    double sd = llvm_sqrt(d);
    printf("sqrt(%lf) = %lf\n", d, sd);

    real r;
    printf("Enter real: ");
    //scanf("%llf", &r);
    r = 3.2311167891231231234754764576;
    real sr = llvm_sqrt(r);
    printf("sqrt(%Lf) = %Lf\n", r, sr);
}