backend: use el_scancommas to skip over OPcomma chains

compiler/src/dmd/backend/blockopt.d

@@ -851,8 +851,7 @@ private void bropt()
     {
         elem **pn = &(b.Belem);
         if (OPTIMIZER && *pn)
-            while ((*pn).Eoper == OPcomma)
+            pn = el_scancommas(pn);
-                pn = &((*pn).EV.E2);
 
         elem *n = *pn;
 
@@ -927,8 +926,7 @@ private void bropt()
         }
         else if (b.BC == BCswitch)
         {   /* see we can evaluate this switch now  */
-            while (n.Eoper == OPcomma)
+            n = *el_scancommas(&n);
-                n = n.EV.E2;
             if (n.Eoper != OPconst)
                 continue;
             assert(tyintegral(n.Ety));
@@ -1803,20 +1801,13 @@ private void brtailrecursion()
             if (el_anyframeptr(*pe))    // if any OPframeptr's
                 return;
 
-            static elem** skipCommas(elem** pe)
+            pe = el_scancommas(pe);
-            {
-                while ((*pe).Eoper == OPcomma)
-                    pe = &(*pe).EV.E2;
-                return pe;
-            }
-
-            pe = skipCommas(pe);
 
             elem *e = *pe;
 
             static bool isCandidate(elem* e)
             {
-                e = *skipCommas(&e);
+                e = *el_scancommas(&e);
                 if (e.Eoper == OPcond)
                     return isCandidate(e.EV.E2.EV.E1) || isCandidate(e.EV.E2.EV.E2);
 
@@ -1990,9 +1981,7 @@ private void emptyloops()
                 continue;
 
             // Find einit
-            elem *einit;
+            elem *einit = *el_scancommas(&(bpred.Belem));
-            for (einit = bpred.Belem; einit.Eoper == OPcomma; einit = einit.EV.E2)
-            { }
             if (einit.Eoper != OPeq ||
                 einit.EV.E2.Eoper != OPconst ||
                 einit.EV.E1.Eoper != OPvar)

compiler/src/dmd/backend/cg87.d

@@ -273,8 +273,7 @@ void note87(elem *e, uint offset, int i, int linnum)
     }
     assert(i < global87.stackused);
 
-    while (e.Eoper == OPcomma)
+    e = *el_scancommas(&e);
-        e = e.EV.E2;
     global87.stack[i].e = e;
     global87.stack[i].offset = offset;
 }
@@ -310,8 +309,7 @@ private void makesure87(ref CodeBuilder cdb,elem *e,uint offset,int i,uint flag,
 {
     debug if (NDPP) printf("makesure87(e=%p, offset=%d, i=%d, flag=%d, line=%d)\n",e,offset,i,flag,linnum);
 
-    while (e.Eoper == OPcomma)
+    e = *el_scancommas(&e);
-        e = e.EV.E2;
     assert(e && i < 4);
 L1:
     if (global87.stack[i].e != e || global87.stack[i].offset != offset)
@@ -2021,8 +2019,7 @@ void eq87(ref CodeBuilder cdb,elem *e,regm_t *pretregs)
         if (*pretregs & (mST0 | ALLREGS | mBP | XMMREGS)) // if want result on stack too
         {   // Make sure it's still there
             elem *e2 = e.EV.E2;
-            while (e2.Eoper == OPcomma)
+            e2 = *el_scancommas(&e2);
-                e2 = e2.EV.E2;
             note87(e2,0,0);
             getlvalue87(cdb, cs, e.EV.E1, 0);
             makesure87(cdb,e2,0,0,1);

compiler/src/dmd/backend/cgelem.d

@@ -3677,8 +3677,7 @@ elem * elstruct(elem *e, goal_t goal)
                 pe2 = &e.EV.E1;
             else
                 break;
-            while ((*pe2).Eoper == OPcomma)
+            pe2 = el_scancommas(pe2);
-                pe2 = &(*pe2).EV.E2;
             elem *e2 = *pe2;
 
             if (e2.Eoper == OPvar)

compiler/src/dmd/backend/cod1.d

@@ -84,8 +84,7 @@ int isscaledindex(elem *e)
     targ_uns ss;
 
     assert(!I16);
-    while (e.Eoper == OPcomma)
+    e = *el_scancommas(&e);
-        e = e.EV.E2;
     if (!(e.Eoper == OPshl && !e.Ecount &&
           e.EV.E2.Eoper == OPconst &&
           (ss = e.EV.E2.EV.Vuns) <= 3

compiler/src/dmd/backend/elem.d

@@ -1180,14 +1180,16 @@ bool el_returns(const(elem)* e)
 
 /********************************
  * Scan down commas and return the controlling elem.
+ * Extra layer of indirection so we can update
+ * (*ret)
  */
 
 @trusted
-elem *el_scancommas(elem *e)
+elem **el_scancommas(elem **pe)
 {
-    while (e.Eoper == OPcomma)
+    while ((*pe).Eoper == OPcomma)
-        e = e.EV.E2;
+        pe = &(*pe).EV.E2;
-    return e;
+    return pe;
 }
 
 /***************************

compiler/src/dmd/backend/gother.d

@@ -1910,8 +1910,7 @@ public void verybusyexp()
         pn = &(b.Belem);
         if (*pn)
         {
-            while ((*pn).Eoper == OPcomma)
+            pn = el_scancommas(pn);
-                pn = &((*pn).EV.E2);
             /* If last statement has side effects,  */
             /* don't do these VBEs. Potentially we  */
             /* could by assigning the result to     */

compiler/src/dmd/e2ir.d

@@ -420,10 +420,7 @@ elem *addressElem(elem *e, Type t, bool alwaysCopy = false)
 {
     //printf("addressElem()\n");
 
-    elem **pe;
+    elem **pe  = el_scancommas(&e);
-    for (pe = &e; (*pe).Eoper == OPcomma; pe = &(*pe).EV.E2)
-    {
-    }
 
     // For conditional operator, both branches need conversion.
     if ((*pe).Eoper == OPcond)