Comment author: @yakobowski

The culprit seems to be an unfortunate interaction between Alain's work on sharing constants, and Xavier's work on floating-point constant propagation. The ~shared argument to Compilenv.new_structured_constant is probably responsible for sharing 0. and -0., since Pervasives.compare does not distinguish them. Implementing a proper comparison function in Compilenv.CstMap may be the solution.

Comment author: @yakobowski

I'm not OCaml-compiler savvy enough to fix the comparison function, but I can confirm that disabling the sharing of float constants in closure.ml fixes our issue.

Comment author: @xavierleroy

Hello Boris,

I confirm that the problem is sharing of constants that are equal in the sense of (=). Constant propagation is innocent :-) Will look into it soon.

Comment author: @xavierleroy

Fixed in 4.02 branch (commit 14916) and on trunk (commit 14917). Patch against 4.02 is attached.