Correct selection of -: vs. +:

Adds new updown field to struct vrange
Both cases exercised by examples/partselect.vhd

7 files changed, 45 insertions, 38 deletions

diff --git a/examples/partselect.vhd b/examples/partselect.vhd
index 25279dd..564f820 100644
--- a/examples/partselect.vhd
+++ b/examples/partselect.vhd
@@ -15,12 +15,14 @@ begin
 
    test_i: process(clk_i)
       variable big_var : std_logic_vector(31 downto 0);
+      variable lit_var : std_logic_vector(0 to 31);
       variable j       : integer; -- XXX not ready for :=8;
    begin
       if rising_edge(clk_i) then
          big_sig(31 downto 24) <= big_sig(7 downto 0);
          big_var(31 downto 24) := big_var(7 downto 0);
-         lit_sig(24 to 31)     <= lit_sig(0 to 7);
+         lit_sig(i*3 to i*3+7)     <= lit_sig(0 to 7);
+         lit_var(j*3 to j*3+8)     <= lit_var(j*0 to 8+j*0);
          --
          big_sig(i*3+8 downto i*3) <= big_sig(8 downto 0);
          big_var(j*3+8 downto j*3) := big_var(j*0+8 downto j*0);
diff --git a/src/def.h b/src/def.h
index cd51456..85acc95 100644
--- a/src/def.h
+++ b/src/def.h
@@ -54,6 +54,7 @@ typedef struct vrange {
   struct slist *nhi, *nlo; /* MAG index is a simple expression */
   slist *size_expr;        /* expression that calculates size (width) of this vrange */
   int    sizeval;          /* precalculated size value */
+  int    updown;           /* only used for indext part select case */
   struct slist *xhi, *xlo; /* array index range; 0,0 for normal scalars */
 } vrange;
 
diff --git a/src/vhd2vl.y b/src/vhd2vl.y
index 20bab8e..0e116ce 100644
--- a/src/vhd2vl.y
+++ b/src/vhd2vl.y
@@ -313,10 +313,10 @@ slist *addpar_snug(slist *sl, vrange *v){
     sl=addtxt(sl,"[");
     if(v->nhi != NULL){
       sl=addsl(sl,v->nhi);
-      if(v->sizeval==-2) sl=addtxt(sl,"+");
-      sl=addtxt(sl,":");
+      if(v->updown) sl=addtxt(sl,v->updown==1 ? " +: " : " -: ");
+      else sl=addtxt(sl,":");
     }
-    if(v->sizeval==-2){
+    if(v->updown){
       sl=addsl(sl,v->size_expr);
       sl=addtxt(sl," + 1");
     } else {
@@ -449,20 +449,21 @@ char *string_check_diff(char *s1, char *s2)
   return rv;
 }
 
-/* look for common beginning or end of a string,
- * needed for creating indexed part selects */
-char *slist_check_diff(slist *shi, slist *slo)
+/* Look for common beginning or end of a string,
+ * as needed for creating indexed part selects.
+ * updown key:  DOWNTO = -1, TO = 1 */
+char *slist_check_diff(slist *shi, slist *slo, int updown)
 {
   char t1[200], t2[200];
   char *diff = 0;
   size_t t1len, t2len;
   sslprint(t1, sizeof(t1), shi);  t1len = strlen(t1);
   sslprint(t2, sizeof(t2), slo);  t2len = strlen(t2);
-  if (t2len < t1len) {
+  if (updown == -1 && t2len < t1len) {
     diff = string_check_diff(t1, t2);
-  } else {
+  } else if (updown == 1 && t1len < t2len) {
     diff = string_check_diff(t2, t1);
-  }
+  } /* I don't have sane test cases for the other possibilities */
   return diff;
 }
 
@@ -1201,6 +1202,7 @@ vec_range : simple_expr updown simple_expr {
               $$->nhi=$1->sl;
               $$->nlo=$3->sl;
               $$->sizeval = -1; /* undefined size */
+              $$->updown = 0; /* not relevant */
               /* Here is where we may want to analyze the two expressions to
                * see if they have a simple (possibly constant) difference.
                * For now, here's an option to visualise their data structures.
@@ -1222,9 +1224,9 @@ vec_range : simple_expr updown simple_expr {
                 } else {      /* (nhi:natural to     nlo:natural) */
                   $$->sizeval = $3->value - $1->value + 1;
                 }
-              } else if ((range_diff = slist_check_diff($$->nhi, $$->nlo))) {
+              } else if ((range_diff = slist_check_diff($$->nhi, $$->nlo, $2))) {
                 if (DEBUG_RANGE) fprintf(stderr, "difference: %s\n", range_diff);
-                $$->sizeval = -2;  /* special */
+                $$->updown = $2;  /* triggers use of range_diff in addpar_snug */
                 $$->size_expr = addtxt(NULL, range_diff);
               } else {
                 /* make an expression to calculate the width of this vrange:
diff --git a/translated_examples/bigfile.v b/translated_examples/bigfile.v
index 26a3ae3..974dc55 100644
--- a/translated_examples/bigfile.v
+++ b/translated_examples/bigfile.v
@@ -187,7 +187,7 @@ wire [31:0] g_dout_i;
           //vnavigatoron
           case(g_dout_w0x0f_v)
           g_t_klim_w0x0f : begin
-            g_t_klim_dout <= din[i * 32 + 31+:31 + 1];
+            g_t_klim_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_t_u_w0x0f : begin
             // output klim
@@ -198,68 +198,68 @@ wire [31:0] g_dout_i;
             end
           end
           g_t_l_w0x0f : begin
-            g_t_l_dout <= din[i * 32 + 31+:31 + 1];
+            g_t_l_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_t_hhh_l_w0x0f : begin
-            g_t_hhh_l_dout <= din[i * 32 + 31+:31 + 1];
+            g_t_hhh_l_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_t_jkl_sink_l_w0x0f : begin
-            g_t_jkl_sink_l_dout <= din[i * 32 + 31+:31 + 1];
+            g_t_jkl_sink_l_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_secondary_t_l_w0x0f : begin
-            g_secondary_t_l_dout <= din[i * 32 + 31+:31 + 1];
+            g_secondary_t_l_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_style_c_l_w0x0f : begin
-            g_style_c_l_dout[3:0] <= din[3 + i * 32+:3 + 1];
+            g_style_c_l_dout[3:0] <= din[3 + i * 32 -: 3 + 1];
           end
           g_e_z_w0x0f : begin
-            g_e_z_dout <= din[i * 32 + 31+:31 + 1];
+            g_e_z_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_n_both_qbars_l_w0x0f : begin
-            g_n_both_qbars_l_dout <= din[i * 32 + 31+:31 + 1];
+            g_n_both_qbars_l_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_style_vfr_w0x0f : begin
             // read-only register
           end
           g_style_klim_w0x0f : begin
-            g_style_klim_dout <= din[i * 32 + 31+:31 + 1];
+            g_style_klim_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_unklimed_style_vfr_w0x0f : begin
             // read-only register
           end
           g_style_t_y_w0x0f : begin
-            g_style_t_y_dout <= din[i * 32 + 31+:31 + 1];
+            g_style_t_y_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_n_l_w0x0f : begin
-            g_n_l_dout <= din[i * 32 + 31+:31 + 1];
+            g_n_l_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_n_vfr_w0x0f : begin
             // writes
           end
           g_e_n_r_w0x0f : begin
-            g_e_n_r_dout <= din[i * 32 + 31+:31 + 1];
+            g_e_n_r_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_n_r_bne_w0x0f : begin
             g_n_r_bne_dout <= din[i * 32];
           end
           g_n_div_rebeq_w0x0f : begin
-            g_n_div_rebeq_dout <= din[i * 32 + 31+:31 + 1] | g_n_div_rebeq_dout;
+            g_n_div_rebeq_dout <= din[i * 32 + 31 -: 31 + 1] | g_n_div_rebeq_dout;
             // a '1' writes
           end
           g_alu_l_w0x0f : begin
-            g_alu_l_dout <= din[i * 32 + 31+:31 + 1];
+            g_alu_l_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_t_qaz_mult_low_w0x0f : begin
-            g_t_qaz_mult_low_dout <= din[i * 32 + 31+:31 + 1];
+            g_t_qaz_mult_low_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           g_t_qaz_mult_high_w0x0f : begin
-            g_t_qaz_mult_high_dout <= din[i * 32 + 31+:31 + 1];
+            g_t_qaz_mult_high_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           gwerthernal_style_u_w0x0f : begin
-            gwerthernal_style_u_dout <= din[i * 32 + 31+:31 + 1];
+            gwerthernal_style_u_dout <= din[i * 32 + 31 -: 31 + 1];
           end
           gwerthernal_style_l_w0x0f : begin
-            gwerthernal_style_l_dout <= din[i * 32 + 31+:31 + 1];
+            gwerthernal_style_l_dout <= din[i * 32 + 31 -: 31 + 1];
             //vnavigatoroff                                                          
           end
           default : begin
@@ -404,15 +404,15 @@ wire [31:0] g_dout_i;
       idiv8 = i / 8;
       if((g_n_r_bne_dout == 1'b0)) begin
         // non-unique
-        g_vector[8 * i + 7+:7 + 1] <= g_e_n_r_dout[8 * idiv8 + 7+:7 + 1];
+        g_vector[8 * i + 7 -: 7 + 1] <= g_e_n_r_dout[8 * idiv8 + 7 -: 7 + 1];
       end
       else begin
         // unique
         if((imod8 == 0)) begin
-          g_vector[8 * i + 7+:7 + 1] <= g_e_n_r_dout[8 * idiv8 + 7+:7 + 1];
+          g_vector[8 * i + 7 -: 7 + 1] <= g_e_n_r_dout[8 * idiv8 + 7 -: 7 + 1];
         end
         else begin
-          g_vector[8 * i + 7+:7 + 1] <= (g_e_n_r_dout[8 * idiv8 + 7+:7 + 1]) + (imod8);
+          g_vector[8 * i + 7 -: 7 + 1] <= (g_e_n_r_dout[8 * idiv8 + 7 -: 7 + 1]) + (imod8);
         end
       end
     end
diff --git a/translated_examples/dsp.v b/translated_examples/dsp.v
index fe4331e..557ca0d 100644
--- a/translated_examples/dsp.v
+++ b/translated_examples/dsp.v
@@ -34,7 +34,7 @@ wire [31:0] iparam;
     if(we == 1'b1) begin
       sr <= {sr[thing_size - bus_width - 1:0],din};
     end
-    dout <= sr[iparam * bus_width + bus_width - 1+:bus_width - 1 + 1];
+    dout <= sr[iparam * bus_width + bus_width - 1 -: bus_width - 1 + 1];
   end
 
 
diff --git a/translated_examples/for.v b/translated_examples/for.v
index 707d981..ce31bc7 100644
--- a/translated_examples/for.v
+++ b/translated_examples/for.v
@@ -29,7 +29,7 @@ reg [6:0] egg_timer;
       for (i=0; i <= j * k; i = i + 1) begin
         a = a + i;
         for (k=a - 9; k >=  -14; k = k - 1) begin
-          zz5 = zz[31 + k+:31 + 1];
+          zz5 = zz[31 + k -: 31 + 1];
         end
         // k
       end
diff --git a/translated_examples/partselect.v b/translated_examples/partselect.v
index 2197b0b..7c8640a 100644
--- a/translated_examples/partselect.v
+++ b/translated_examples/partselect.v
@@ -13,15 +13,17 @@ wire [31:0] i = 8;
 
   always @(posedge clk_i) begin : P1
     reg [31:0] big_var;
+    reg [0:31] lit_var;
     reg [31:0] j;
   // XXX not ready for :=8;
 
     big_sig[31:24] <= big_sig[7:0];
     big_var[31:24] = big_var[7:0];
-    lit_sig[24:31] <= lit_sig[0:7];
+    lit_sig[i * 3 +: 7 + 1] <= lit_sig[0:7];
+    lit_var[j * 3 +: 8 + 1] <= lit_var[j * 0 +: 8 + 1];
     //
-    big_sig[i * 3 + 8+:8 + 1] <= big_sig[8:0];
-    big_var[j * 3 + 8+:8 + 1] = big_var[j * 0 + 8+:8 + 1];
+    big_sig[i * 3 + 8 -: 8 + 1] <= big_sig[8:0];
+    big_var[j * 3 + 8 -: 8 + 1] = big_var[j * 0 + 8 -: 8 + 1];
   end