src/backend/cgcs.c

@@ -233,6 +233,7 @@ STATIC void ecom(elem **pe)
     case OPbtc:
     case OPbts:
     case OPbtr:
+    case OPcmpxchg:
         ecom(&e->E1);
         ecom(&e->E2);
         touchfunc(0);                   // indirect assignment

src/backend/cod4.c

@@ -3767,4 +3767,84 @@ code *cdpair(elem *e, regm_t *pretregs)
     return cat4(c1,c2,cg,fixresult(e,regs1 | regs2,pretregs));
 }
 
+/*************************
+ * Generate code for OPcmpxchg
+ */
+
+code *cdcmpxchg(elem *e, regm_t *pretregs)
+{
+    /* The form is:
+     *     OPcmpxchg
+     *    /     \
+     * lvalue   OPparam
+     *          /     \
+     *        old     new
+     */
+    code *cr1,*cr,*cl,*c,cs;
+
+    //printf("cdmulass(e=%p, *pretregs = %s)\n",e,regm_str(*pretregs));
+    elem *e1 = e->E1;
+    elem *e2 = e->E2;
+    assert(e2->Eoper == OPparam);
+    assert(!e2->Ecount);
+
+    tym_t tyml = tybasic(e1->Ety);              // type of lvalue
+    unsigned sz = tysize[tyml];
+
+    if (I32 && sz == 8)
+    {
+        regm_t retregs = mDX|mAX;
+        cr1 = codelem(e2->E1,&retregs,FALSE);         // [DX,AX] = e2->E1
+
+        retregs = mCX|mBX;
+        cr = scodelem(e2->E2,&retregs,mDX|mAX,FALSE); // [CX,BX] = e2->E2
+        cl = getlvalue(&cs,e1,mCX|mBX|mAX|mDX);       // get EA
+        cs.Iop = 0x0FC7;                              // CMPXCHG8B EA
+        cs.Iflags |= CFpsw;
+        code_newreg(&cs,1);
+        c = getregs(mDX|mAX);                         // CMPXCHG destroys these regs
+        if (e1->Ety & mTYvolatile)
+            c = gen1(c,LOCK);                         // LOCK prefix
+        c = gen(c,&cs);
+        assert(!e1->Ecount);
+        freenode(e1);
+    }
+    else
+    {
+        unsigned byte = (sz == 1);                  // 1 for byte operation
+        unsigned char word = (!I16 && sz == SHORTSIZE) ? CFopsize : 0;
+        unsigned rex = (I64 && sz == 8) ? REX_W : 0;
+
+        regm_t retregs = mAX;
+        cr1 = codelem(e2->E1,&retregs,FALSE);   // AX = e2->E1
+
+        retregs = (ALLREGS | mBP) & ~mAX;
+        cr = scodelem(e2->E2,&retregs,mAX,FALSE);   // load rvalue in reg
+        cl = getlvalue(&cs,e1,mAX | retregs);       // get EA
+        cs.Iop = 0x0FB1 ^ byte;                     // CMPXCHG EA,reg
+        cs.Iflags |= CFpsw | word;
+        cs.Irex |= rex;
+        unsigned reg = findreg(retregs);
+        code_newreg(&cs,reg);
+        c = getregs(mAX);                               // CMPXCHG destroys AX
+        if (e1->Ety & mTYvolatile)
+            c = gen1(c,LOCK);                   // LOCK prefix
+        c = gen(c,&cs);
+        assert(!e1->Ecount);
+        freenode(e1);
+    }
+
+    regm_t retregs;
+    if ((retregs = (*pretregs & (ALLREGS | mBP))) != 0) // if return result in register
+    {
+        unsigned reg;
+        code *cg = allocreg(&retregs,&reg,TYint);
+        cg = gen2(cg,0x0F94,modregrmx(3,0,reg));        // SETZ reg
+        *pretregs = retregs;
+        c = cat(c,cg);
+    }
+
+    return cat4(cr1,cr,cl,c);
+}
+
 #endif // !SPP

src/backend/code.h

@@ -321,6 +321,7 @@ code *getoffset (elem *e , unsigned reg );
 cd_t cdneg;
 cd_t cdabs;
 cd_t cdpost;
+cd_t cdcmpxchg;
 cd_t cderr;
 cd_t cdinfo;
 cd_t cddctor;

src/backend/code_x86.h

@@ -205,6 +205,7 @@ extern regm_t BYTEREGS;
 #define LOOP    0xE2
 #define LES     0xC4
 #define LEA     0x8D
+#define LOCK    0xF0
 
 #define JO      0x70
 #define JNO     0x71

src/backend/glocal.c

@@ -189,6 +189,7 @@ STATIC void local_exp(elem *e,int goal)
         case OPandass:
         case OPxorass:
         case OPorass:
+        case OPcmpxchg:
             if (ERTOL(e))
             {   local_exp(e->E2,1);
         case OPnegass:
@@ -561,6 +562,7 @@ STATIC int local_getflags(elem *e,symbol *s)
             case OPandass:
             case OPxorass:
             case OPorass:
+            case OPcmpxchg:
                 if (e->E1->Eoper == OPvar)
                 {   symbol *s1;
 

src/backend/gloop.c

@@ -929,6 +929,7 @@ STATIC void markinvar(elem *n,vec_t rd)
         case OPpostinc: case OPpostdec:
         case OPcall:
         case OPvecsto:
+        case OPcmpxchg:
                         markinvar(n->E2,rd);
         case OPnegass:
                         n1 = n->E1;

src/backend/gother.c

@@ -1257,6 +1257,10 @@ void elimass(elem *n)
         case OPbts:
             n->Eoper = OPbt;
             break;
+        case OPcmpxchg:
+            n->Eoper = OPcomma;
+            n->E2->Eoper = OPcomma;
+            break;
         default:
             assert(0);
     }

src/backend/oper.h

@@ -55,6 +55,7 @@ enum OPER
         OPscale,                // ldexp
         OPyl2x,                 // y * log2(x)
         OPyl2xp1,               // y * log2(x + 1)
+        OPcmpxchg,                      // cmpxchg
 #endif
         OPstrlen,               /* strlen()                     */
         OPstrcpy,               /* strcpy()                     */

src/backend/optabgen.c

@@ -41,7 +41,7 @@ int _binary[] =
          OPinfo,OParray,OPfield,OPnewarray,OPmultinewarray,OPinstanceof,OPfinalinstanceof,
          OPcheckcast,OPpair,OPrpair,
          OPbt,OPbtc,OPbtr,OPbts,OPror,OProl,OPbtst,
-         OPremquo,
+         OPremquo,OPcmpxchg,
 #if TX86
          OPoutp,OPscale,OPyl2x,OPyl2xp1,
          OPvecsto,
@@ -83,7 +83,7 @@ int _assoc[] = {OPadd,OPand,OPor,OPxor,OPmul};
 int _assign[] =
         {OPstreq,OPeq,OPaddass,OPminass,OPmulass,OPdivass,OPmodass,
          OPshrass,OPashrass,OPshlass,OPandass,OPxorass,OPorass,OPpostinc,OPpostdec,
-         OPnegass,OPvecsto,
+         OPnegass,OPvecsto,OPcmpxchg,
         };
 int _wid[] =
         {OPadd,OPmin,OPand,OPor,OPxor,OPcom,OPneg,OPmul,OPaddass,OPnegass,
@@ -113,7 +113,7 @@ int _def[] = {OPstreq,OPeq,OPaddass,OPminass,OPmulass,OPdivass,OPmodass,
                 OPcall,OPucall,OPasm,OPstrcpy,OPmemcpy,OPmemset,OPstrcat,
                 OPnegass,OPnewarray,OPmultinewarray,
                 OPbtc,OPbtr,OPbts,
-                OPvecsto,
+                OPvecsto,OPcmpxchg,
              };
 int _sideff[] = {OPasm,OPucall,OPstrcpy,OPmemcpy,OPmemset,OPstrcat,
                 OPcall,OPeq,OPstreq,OPpostinc,OPpostdec,
@@ -123,6 +123,7 @@ int _sideff[] = {OPasm,OPucall,OPstrcpy,OPmemcpy,OPmemset,OPstrcat,
                 OPmultinewarray,OPcheckcast,OPnullcheck,
                 OPbtc,OPbtr,OPbts,
                 OPhalt,OPdctor,OPddtor,
+                OPcmpxchg,
 #if TX86 && MARS
                 OPva_start,
 #endif
@@ -134,7 +135,7 @@ int _rtol[] = {OPeq,OPstreq,OPstrcpy,OPmemcpy,OPpostinc,OPpostdec,OPaddass,
                 OPminass,OPmulass,OPdivass,OPmodass,OPandass,
                 OPorass,OPxorass,OPshlass,OPshrass,OPashrass,
                 OPcall,OPcallns,OPinfo,OPmemset,
-                OPvecsto,
+                OPvecsto,OPcmpxchg,
                 };
 int _ae[] = {OPvar,OPconst,OPrelconst,OPneg,
                 OPabs,OPrndtol,OPrint,
@@ -184,7 +185,7 @@ int _exp[] = {OPvar,OPconst,OPrelconst,OPneg,OPabs,OPrndtol,OPrint,
                 OPorass,OPxorass,OPshlass,OPshrass,OPashrass,OPoror,OPandand,OPcond,
                 OPbsf,OPbsr,OPbt,OPbtc,OPbtr,OPbts,OPbswap,OPbtst,OPpopcnt,
                 OProl,OPror,OPvector,
-                OPpair,OPrpair,OPframeptr,OPgot,OPremquo,
+                OPpair,OPrpair,OPframeptr,OPgot,OPremquo,OPcmpxchg,
                 OPcolon,OPcolon2,OPasm,OPstrcpy,OPmemcpy,OPmemset,OPstrcat,OPnegass,
 #if TX86
                 OPsqrt,OPsin,OPcos,OPscale,OPyl2x,OPyl2xp1,
@@ -517,6 +518,7 @@ void dotab()
         case OPyl2x:    X("yl2x",       elzot,  cdscale);
         case OPyl2xp1:  X("yl2xp1",     elzot,  cdscale);
 #endif
+        case OPcmpxchg:     X("cas",        elzot,  cdcmpxchg);
         case OPrint:    X("rint",       evalu8, cdneg);
         case OPrndtol:  X("rndtol",     evalu8, cdrndtol);
         case OPstrlen:  X("strlen",     elzot,  cdstrlen);