Hello all, I was wondering if the following style of register assignment ever shows up in C-- code generated by GHC: a = R1 I32[a] = 1 a = R2 I32[a] = 2 That is to say, there are two disjoint live ranges of a: we could rename all instances of a in the first and second lines to something different without affecting the semantics (although maybe affecting register allocation and stack spilling.) asdf = R1 I32[asdf] = 1 a = R2 I32[a] = 2 But C-- is not in SSA form, and even when no loops are involved it seems that some naughty code generator could reuse a variable. This is pretty inconvenient, because I want to record this information a = R1 // used only once I32[a] = 1 a = R2 // used only once I32[a] = 2 in a map: a -> used only once But since the register names go all the same place this may end in tears. If multiple assignment is rare enough in straight line code, I might be able to take the conservative approach and just say a -> used multiple times Which I don't think will cause any problems in the inlining step later. But I don't have a good sense for this. Edward