Bug 19599 – Wrong codegen DMD x86_64 with both -O and -inline + double

DMD v2.081.2 Build this with: dmd repro.d -m64 -inline -O --------- repro.d ----------- struct double2 { double[2] array; this(double[2] v) pure nothrow @safe @nogc { array[] = v[]; } ref inout(double) opIndex(size_t i) inout pure nothrow @safe @nogc { return array[i]; } } double2 _mm_sub_sd(double2 a, double2 b) pure @safe { a[0] -= b[0]; return a; } void main() { double2 a = [1.0, -2.0]; a = _mm_sub_sd(a, a); assert(a.array == [0.0, -2.0]); } ``` The assert doesn't pass. Instead a is equal to [1.0, -2.0]. It should be exactly [0.0, -2.0]

Also in dmd.2.084.0 + windows

Cannot reproduce in v2.094.0, was probabyl fixed at one point?

Can confirm it is working now in master. (Don't know what change fixed it.) If you find some other variation on this that does not work, please file another bug report.