In Regalloc, dead code elimination, don't eliminate move operations

that pop the x87 FP stack (var <- FP0).  Otherwise, (void) f();
where f returns a float eventually produces a FP stack overflow.


git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2416 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

1 files changed, 3 insertions, 0 deletions

diff --git a/ia32/Machregs.v b/ia32/Machregs.v
index 47340ec..85b561e 100644
--- a/ia32/Machregs.v
+++ b/ia32/Machregs.v
@@ -69,6 +69,9 @@ Module IndexedMreg <: INDEXED_TYPE.
   Qed.
 End IndexedMreg.
 
+Definition is_stack_reg (r: mreg) : bool :=
+  match r with FP0 => true | _ => false end.
+
 (** ** Destroyed registers, preferred registers *)
 
 Definition destroyed_by_op (op: operation): list mreg :=