made the previous changes in parameter passing mechanism and return

value mechanism settable with compile time constants

diff --git a/lang/m2/comp/BigPars b/lang/m2/comp/BigPars
index d22fe08..acca3a2 100644 (file)
--- a/lang/m2/comp/BigPars
+++ b/lang/m2/comp/BigPars
@@ -76,3 +76,18 @@
                                */
 
 
+!File: bigparam.h
+#define PASS_BIG_VAL_AS_VAR 1  /* define when big value parameters must be
+                                  passed as addresses
+                               */
+
+
+!File: bigresult.h
+#define BIG_RESULT_ON_STACK 1  /* define when function results must be
+                                  put on the stack; in this case, caller
+                                  reserves space for it. When not defined,
+                                  callee puts result in global data area and
+                                  returns a pointer to it
+                               */
+
+

diff --git a/lang/m2/comp/Makefile b/lang/m2/comp/Makefile
index 805c4c6..170d427 100644 (file)
--- a/lang/m2/comp/Makefile
+++ b/lang/m2/comp/Makefile
@@ -43,7 +43,7 @@ SRC = $(CSRC) $(GENC)
 OBJ =  $(COBJ) $(LOBJ) Lpars.o
 
 GENH=  errout.h\
-       idfsize.h numsize.h strsize.h target_sizes.h \
+       idfsize.h numsize.h strsize.h target_sizes.h bigparam.h bigresult.h \
        inputtype.h density.h squeeze.h nocross.h nostrict.h \
        def.h debugcst.h type.h Lpars.h node.h desig.h strict3rd.h
 HFILES=                LLlex.h\
@@ -178,6 +178,7 @@ $(CURRDIR)cemain:      $(OBJ) $(CURRDIR)Makefile
 #AUTOAUTOAUTOAUTOAUTOAUTOAUTOAUTO
 LLlex.o: LLlex.h
 LLlex.o: Lpars.h
+LLlex.o: bigparam.h
 LLlex.o: class.h
 LLlex.o: const.h
 LLlex.o: debug.h
@@ -212,6 +213,7 @@ error.o: warning.h
 main.o: LLlex.h
 main.o: Lpars.h
 main.o: SYSTEM.h
+main.o: bigparam.h
 main.o: debug.h
 main.o: debugcst.h
 main.o: def.h
@@ -236,6 +238,7 @@ input.o: f_info.h
 input.o: input.h
 input.o: inputtype.h
 type.o: LLlex.h
+type.o: bigparam.h
 type.o: chk_expr.h
 type.o: const.h
 type.o: debug.h
@@ -253,6 +256,7 @@ type.o: walk.h
 type.o: warning.h
 def.o: LLlex.h
 def.o: Lpars.h
+def.o: bigparam.h
 def.o: debug.h
 def.o: debugcst.h
 def.o: def.h
@@ -270,6 +274,7 @@ misc.o: idf.h
 misc.o: misc.h
 misc.o: node.h
 enter.o: LLlex.h
+enter.o: bigparam.h
 enter.o: debug.h
 enter.o: debugcst.h
 enter.o: def.h
@@ -284,6 +289,7 @@ enter.o: target_sizes.h
 enter.o: type.h
 defmodule.o: LLlex.h
 defmodule.o: Lpars.h
+defmodule.o: bigparam.h
 defmodule.o: debug.h
 defmodule.o: debugcst.h
 defmodule.o: def.h
@@ -299,6 +305,7 @@ defmodule.o: scope.h
 defmodule.o: target_sizes.h
 defmodule.o: type.h
 typequiv.o: LLlex.h
+typequiv.o: bigparam.h
 typequiv.o: debug.h
 typequiv.o: debugcst.h
 typequiv.o: def.h
@@ -311,6 +318,7 @@ typequiv.o: target_sizes.h
 typequiv.o: type.h
 typequiv.o: warning.h
 node.o: LLlex.h
+node.o: bigparam.h
 node.o: debug.h
 node.o: debugcst.h
 node.o: def.h
@@ -321,6 +329,7 @@ node.o: target_sizes.h
 node.o: type.h
 cstoper.o: LLlex.h
 cstoper.o: Lpars.h
+cstoper.o: bigparam.h
 cstoper.o: debug.h
 cstoper.o: debugcst.h
 cstoper.o: idf.h
@@ -332,6 +341,7 @@ cstoper.o: type.h
 cstoper.o: warning.h
 chk_expr.o: LLlex.h
 chk_expr.o: Lpars.h
+chk_expr.o: bigparam.h
 chk_expr.o: chk_expr.h
 chk_expr.o: const.h
 chk_expr.o: debug.h
@@ -349,6 +359,7 @@ chk_expr.o: strict3rd.h
 chk_expr.o: target_sizes.h
 chk_expr.o: type.h
 chk_expr.o: warning.h
+options.o: bigparam.h
 options.o: class.h
 options.o: idfsize.h
 options.o: main.h
@@ -361,6 +372,8 @@ options.o: type.h
 options.o: warning.h
 walk.o: LLlex.h
 walk.o: Lpars.h
+walk.o: bigparam.h
+walk.o: bigresult.h
 walk.o: chk_expr.h
 walk.o: debug.h
 walk.o: debugcst.h
@@ -380,6 +393,7 @@ walk.o: type.h
 walk.o: walk.h
 walk.o: warning.h
 desig.o: LLlex.h
+desig.o: bigparam.h
 desig.o: debug.h
 desig.o: debugcst.h
 desig.o: def.h
@@ -394,6 +408,8 @@ desig.o: walk.h
 desig.o: warning.h
 code.o: LLlex.h
 code.o: Lpars.h
+code.o: bigparam.h
+code.o: bigresult.h
 code.o: debug.h
 code.o: debugcst.h
 code.o: def.h
@@ -407,6 +423,7 @@ code.o: target_sizes.h
 code.o: type.h
 code.o: walk.h
 lookup.o: LLlex.h
+lookup.o: bigparam.h
 lookup.o: debug.h
 lookup.o: debugcst.h
 lookup.o: def.h
@@ -420,6 +437,7 @@ lookup.o: type.h
 tokenfile.o: Lpars.h
 program.o: LLlex.h
 program.o: Lpars.h
+program.o: bigparam.h
 program.o: debug.h
 program.o: debugcst.h
 program.o: def.h
@@ -435,6 +453,7 @@ program.o: type.h
 program.o: warning.h
 declar.o: LLlex.h
 declar.o: Lpars.h
+declar.o: bigparam.h
 declar.o: chk_expr.h
 declar.o: debug.h
 declar.o: debugcst.h
@@ -452,6 +471,7 @@ declar.o: type.h
 declar.o: warning.h
 expression.o: LLlex.h
 expression.o: Lpars.h
+expression.o: bigparam.h
 expression.o: chk_expr.h
 expression.o: const.h
 expression.o: debug.h
@@ -465,6 +485,7 @@ expression.o: type.h
 expression.o: warning.h
 statement.o: LLlex.h
 statement.o: Lpars.h
+statement.o: bigparam.h
 statement.o: def.h
 statement.o: idf.h
 statement.o: nocross.h
@@ -477,6 +498,7 @@ char.o: class.h
 Lpars.o: Lpars.h
 casestat.o: LLlex.h
 casestat.o: Lpars.h
+casestat.o: bigparam.h
 casestat.o: chk_expr.h
 casestat.o: debug.h
 casestat.o: debugcst.h
@@ -490,6 +512,7 @@ casestat.o: target_sizes.h
 casestat.o: type.h
 casestat.o: walk.h
 tmpvar.o: LLlex.h
+tmpvar.o: bigparam.h
 tmpvar.o: debug.h
 tmpvar.o: debugcst.h
 tmpvar.o: def.h
@@ -499,6 +522,7 @@ tmpvar.o: scope.h
 tmpvar.o: target_sizes.h
 tmpvar.o: type.h
 scope.o: LLlex.h
+scope.o: bigparam.h
 scope.o: debug.h
 scope.o: debugcst.h
 scope.o: def.h

diff --git a/lang/m2/comp/SmallPars b/lang/m2/comp/SmallPars
index f879fe6..ec72d72 100644 (file)
--- a/lang/m2/comp/SmallPars
+++ b/lang/m2/comp/SmallPars
@@ -76,3 +76,18 @@
                                */
 
 
+!File: bigparam.h
+#undef PASS_BIG_VAL_AS_VAR 1   /* define when big value parameters must be
+                                  passed as addresses
+                               */
+
+
+!File: bigresult.h
+#define BIG_RESULT_ON_STACK 1  /* define when function results must be
+                                  put on the stack; in this case, caller
+                                  reserves space for it. When not defined,
+                                  callee puts result in global data area and
+                                  returns a pointer to it
+                               */
+
+

diff --git a/lang/m2/comp/code.c b/lang/m2/comp/code.c
index 37a4c5d..bad6501 100644 (file)
--- a/lang/m2/comp/code.c
+++ b/lang/m2/comp/code.c
@@ -30,6 +30,7 @@
 #include       "Lpars.h"
 #include       "standards.h"
 #include       "walk.h"
+#include       "bigresult.h"
 
 extern char    *long2str();
 extern char    *symbol2str();
@@ -321,11 +322,12 @@ CodeCall(nd)
 
        assert(IsProc(left));
 
-       if (result_tp = ResultType(left->nd_type)) {
-               if (TooBigForReturnArea(result_tp)) {
-                       C_asp(-WA(result_tp->tp_size));
-               }
+       result_tp = ResultType(left->nd_type);
+#ifdef BIG_RESULT_ON_STACK
+       if (result_tp && TooBigForReturnArea(result_tp)) {
+               C_asp(-WA(result_tp->tp_size));
        }
+#endif
 
        if (nd->nd_right) {
                CodeParameters(ParamList(left->nd_type), nd->nd_right);
@@ -356,9 +358,14 @@ CodeCall(nd)
        }
        C_asp(left->nd_type->prc_nbpar);
        if (result_tp) {
+               arith sz = WA(result_tp->tp_size);
                if (TooBigForReturnArea(result_tp)) {
+#ifndef BIG_RESULT_ON_STACK
+                       C_lfr(pointer_size);
+                       C_loi(sz);
+#endif
                }
-               else    C_lfr(WA(result_tp->tp_size));
+               else    C_lfr(sz);
        }
        DoFilename(needs_fn);
        DoLineno(nd);

diff --git a/lang/m2/comp/type.H b/lang/m2/comp/type.H
index ed2afdc..753d4d8 100644 (file)
--- a/lang/m2/comp/type.H
+++ b/lang/m2/comp/type.H
@@ -226,7 +226,13 @@ extern t_type
                                        (tpx))
 #define        IsConstructed(tpx)      ((tpx)->tp_fund & T_CONSTRUCTED)
 #define        TooBigForReturnArea(tpx) ((tpx)->tp_size > ret_area_size)
+
+#include "bigparam.h"
+#ifdef PASS_BIG_VAL_AS_VAR
 #define IsBigParamTp(tpx)      ((tpx)->tp_size > double_size)
+#else
+#define IsBigParamTp(tpx)      (0)
+#endif PASS_BIG_VAL_AS_VAR
 
 extern long full_mask[];
 extern long max_int[];

diff --git a/lang/m2/comp/walk.c b/lang/m2/comp/walk.c
index 58a690d..7aab1ac 100644 (file)
--- a/lang/m2/comp/walk.c
+++ b/lang/m2/comp/walk.c
@@ -38,6 +38,7 @@
 #include       "walk.h"
 #include       "misc.h"
 #include       "warning.h"
+#include       "bigresult.h"
 
 extern arith           NewPtr();
 extern arith           NewInt();
@@ -234,7 +235,7 @@ WalkProcedure(procedure)
        register t_scope *procscope = procedure->prc_vis->sc_scope;
        register t_type *tp;
        register t_param *param;
-       int too_big = 0;                /* returnsize larger than returnarea */
+       label too_big = 0;              /* returnsize larger than returnarea */
        arith StackAdjustment = 0;      /* space for conformant arrays */
        arith retsav = 0;               /* temporary space for return value */
        arith func_res_size = 0;
@@ -254,11 +255,25 @@ WalkProcedure(procedure)
        if (tp) {
                func_res_size = WA(tp->tp_size);
                if (TooBigForReturnArea(tp)) {
-                       /* The result type of this procedure is constructed.
+#ifdef BIG_RESULT_ON_STACK
+                       /* The result type of this procedure is too big.
                           The caller will have reserved space on its stack,
                           above the parameters, to store the result.
                        */
                        too_big = 1;
+#else
+                       /* The result type of this procedure is too big.
+                          The actual procedure will return a pointer to a
+                          global data area in which the function result is
+                          stored.
+                          Notice that this makes the code non-reentrant.
+                          Here, we create the data area for the function
+                          result.
+                       */
+                       too_big = ++data_label;
+                       C_df_dlb(too_big);
+                       C_bss_cst(func_res_size, (arith)0, 0);
+#endif BIG_RESULT_ON_STACK
                }
        }
 
@@ -378,7 +393,11 @@ WalkProcedure(procedure)
                /* Fill the data area reserved for the function result
                   with the result
                */
+#ifdef BIG_RESULT_ON_STACK
                C_lal(procedure->df_type->prc_nbpar);
+#else
+               c_lae_dlb(too_big);
+#endif BIG_RESULT_ON_STACK
                C_sti(func_res_size);
                if (StackAdjustment) {
                        /* Remove copies of conformant arrays
@@ -386,7 +405,12 @@ WalkProcedure(procedure)
                        LOL(StackAdjustment, pointer_size);
                        C_str((arith) 1);
                }
+#ifdef BIG_RESULT_ON_STACK
                func_res_size = 0;
+#else
+               c_lae_dlb(too_big);
+               func_res_size = pointer_size;
+#endif BIG_RESULT_ON_STACK
        }
        else if (StackAdjustment) {
                /* First save the function result in a safe place.
@@ -406,8 +430,11 @@ WalkProcedure(procedure)
        C_ret(func_res_size);
        C_beginpart(partno2);
        C_pro(procscope->sc_name, -procscope->sc_off);
-       C_ms_par(procedure->df_type->prc_nbpar +
-                (too_big ? func_res_size : 0));
+       C_ms_par(procedure->df_type->prc_nbpar
+#ifdef BIG_RESULT_ON_STACK
+               + (too_big ? func_res_size : 0)
+#endif
+               );
        if (! options['n']) WalkDefList(procscope->sc_def, RegisterMessage);
        C_endpart(partno2);
        C_end(-procscope->sc_off);
@@ -974,9 +1001,11 @@ UseWarnings(df)
                warning = "never used/assigned";
                break;
        case D_USED|D_VARPAR:
+#ifdef PASS_BIG_VAL_AS_VAR
                if (df->df_type->tp_fund != T_EQUAL) {
                        warning = "never assigned, could be value parameter";
                }
+#endif
                break;
        case D_USED:
                warning = "never assigned";