[arm] Fix code generation bug with "mod 1" (PR#5910).

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13662 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

Changes

@@ -35,6 +35,7 @@ Standard library:
   (Marshal.to_*), forcing the output to be readable on 32-bit hosts.
 
 Bug fixes:
+- PR#5910: Fix code generation bug for "mod 1" on ARM.
 - PR#5973: Format module incorrectly parses format string
 - PR#5121: %( %) in Format module seems to be broken
 - PR#4887: input_char after close_in crashes ocaml (msvc runtime)

asmcomp/arm/selection.ml

@@ -174,7 +174,7 @@ method! select_operation op args =
   | (Cdivi, args) ->
       (Iextcall("__aeabi_idiv", false), args)
   | (Cmodi, [arg; Cconst_int n])
-    when n = 1 lsl Misc.log2 n ->
+    when n > 1 && n = 1 lsl Misc.log2 n ->
       (Iintop_imm(Imod, n), [arg])
   | (Cmodi, args) ->
       (* See above for fix up of return register *)