Change the OFFSETCLOSURE bytecode instructions to use an offset of 3 …

…instead of 2 (ocaml#10050)

Replace (PUSH)OFFSETCLOSURE(2|M2) by (PUSH)OFFSETCLOSURE(3|M3) to match the change of representation of closures.

Changes

@@ -207,6 +207,10 @@ OCaml 4.12.0
   in the same thread the allocation takes place
   (Jacques-Henri Jourdan, review by Stephen Dolan)
 
+- #10050: update {PUSH,}OFFSETCLOSURE* bytecode instructions to match new
+  representation for closures
+  (Nathanaël Courant, review by Xavier Leroy)
+
 ### Code generation and optimizations:
 
 - #9551: ocamlc no longer loads DLLs at link time to check that

bytecomp/emitcode.ml

@@ -226,8 +226,8 @@ let emit_instr = function
       let org = !out_position in
       List.iter (out_label_with_orig org) lbls
   | Koffsetclosure ofs ->
-      if ofs = -2 || ofs = 0 || ofs = 2
-      then out (opOFFSETCLOSURE0 + ofs / 2)
+      if ofs = -3 || ofs = 0 || ofs = 3
+      then out (opOFFSETCLOSURE0 + ofs / 3)
       else (out opOFFSETCLOSURE; out_int ofs)
   | Kgetglobal q -> out opGETGLOBAL; slot_for_getglobal q
   | Ksetglobal q -> out opSETGLOBAL; slot_for_setglobal q
@@ -351,8 +351,8 @@ let rec emit = function
       else (out opPUSHENVACC; out_int n);
       emit c
   | Kpush :: Koffsetclosure ofs :: c ->
-      if ofs = -2 || ofs = 0 || ofs = 2
-      then out(opPUSHOFFSETCLOSURE0 + ofs / 2)
+      if ofs = -3 || ofs = 0 || ofs = 3
+      then out(opPUSHOFFSETCLOSURE0 + ofs / 3)
       else (out opPUSHOFFSETCLOSURE; out_int ofs);
       emit c
   | Kpush :: Kgetglobal id :: Kgetfield n :: c ->

runtime/caml/instruct.h

@@ -32,9 +32,9 @@ enum instructions {
   APPTERM, APPTERM1, APPTERM2, APPTERM3,
   RETURN, RESTART, GRAB,
   CLOSURE, CLOSUREREC,
-  OFFSETCLOSUREM2, OFFSETCLOSURE0, OFFSETCLOSURE2, OFFSETCLOSURE,
-  PUSHOFFSETCLOSUREM2, PUSHOFFSETCLOSURE0,
-  PUSHOFFSETCLOSURE2, PUSHOFFSETCLOSURE,
+  OFFSETCLOSUREM3, OFFSETCLOSURE0, OFFSETCLOSURE3, OFFSETCLOSURE,
+  PUSHOFFSETCLOSUREM3, PUSHOFFSETCLOSURE0,
+  PUSHOFFSETCLOSURE3, PUSHOFFSETCLOSURE,
   GETGLOBAL, PUSHGETGLOBAL, GETGLOBALFIELD, PUSHGETGLOBALFIELD, SETGLOBAL,
   ATOM0, ATOM, PUSHATOM0, PUSHATOM,
   MAKEBLOCK, MAKEBLOCK1, MAKEBLOCK2, MAKEBLOCK3, MAKEFLOATBLOCK,

runtime/interp.c

@@ -616,18 +616,18 @@ value caml_interprete(code_t prog, asize_t prog_size)
     Instruct(OFFSETCLOSURE):
       accu = env + *pc++ * sizeof(value); Next;
 
-    Instruct(PUSHOFFSETCLOSUREM2):
+    Instruct(PUSHOFFSETCLOSUREM3):
       *--sp = accu; /* fallthrough */
-    Instruct(OFFSETCLOSUREM2):
-      accu = env - 2 * sizeof(value); Next;
+    Instruct(OFFSETCLOSUREM3):
+      accu = env - 3 * sizeof(value); Next;
     Instruct(PUSHOFFSETCLOSURE0):
       *--sp = accu; /* fallthrough */
     Instruct(OFFSETCLOSURE0):
       accu = env; Next;
-    Instruct(PUSHOFFSETCLOSURE2):
+    Instruct(PUSHOFFSETCLOSURE3):
       *--sp = accu; /* fallthrough */
-    Instruct(OFFSETCLOSURE2):
-      accu = env + 2 * sizeof(value); Next;
+    Instruct(OFFSETCLOSURE3):
+      accu = env + 3 * sizeof(value); Next;
 
 
 /* Access to global variables */

tools/dumpobj.ml

@@ -296,13 +296,13 @@ let op_shapes = [
   opGRAB, Uint;
   opCLOSURE, Uint_Disp;
   opCLOSUREREC, Closurerec;
-  opOFFSETCLOSUREM2, Nothing;
+  opOFFSETCLOSUREM3, Nothing;
   opOFFSETCLOSURE0, Nothing;
-  opOFFSETCLOSURE2, Nothing;
+  opOFFSETCLOSURE3, Nothing;
   opOFFSETCLOSURE, Sint;  (* was Uint *)
-  opPUSHOFFSETCLOSUREM2, Nothing;
+  opPUSHOFFSETCLOSUREM3, Nothing;
   opPUSHOFFSETCLOSURE0, Nothing;
-  opPUSHOFFSETCLOSURE2, Nothing;
+  opPUSHOFFSETCLOSURE3, Nothing;
   opPUSHOFFSETCLOSURE, Sint; (* was Nothing *)
   opGETGLOBAL, Getglobal;
   opPUSHGETGLOBAL, Getglobal;