Improve constant propagation with "&&" and "||".

Edmund Grimley Evans committed 10 years ago

Commit 3ff77a11 parent c7067ae3 files · +58 −52Browse files

Unified · Split

3 files

TODO +0 −1
tccgen.c +53 −50
tests/tests2/78_vla_label.c +5 −1

TODO+0−1

@@ -68,7 +68,6 @@ Not critical: · 67 unmodified lines
68	to suppress VT_LOCAL and use a base register instead).	68	to suppress VT_LOCAL and use a base register instead).
69	- interactive mode / integrated debugger	69	- interactive mode / integrated debugger
70	- fix preprocessor symbol redefinition	70	- fix preprocessor symbol redefinition
71	- better constant opt (&&, \|\|, ?:)
72	- add portable byte code generator and interpreter for other	71	- add portable byte code generator and interpreter for other
73	unsupported architectures.	72	unsupported architectures.
74	- C++: variable declaration in for, minimal 'class' support.	73	- C++: variable declaration in for, minimal 'class' support.

tccgen.c+53−50

     }
 }
-/* XXX: fix this mess */
-static void expr_land_const(void)
-{
-    expr_or();
-    while (tok == TOK_LAND) {
-        next();
-        expr_or();
-        gen_op(TOK_LAND);
-    }
-}
-/* XXX: fix this mess */
-static void expr_lor_const(void)
-{
-    expr_land_const();
-    while (tok == TOK_LOR) {
-        next();
-        expr_land_const();
-        gen_op(TOK_LOR);
-    }
-}
-/* only used if non constant */
 static void expr_land(void)
 {
-    int t;
     expr_or();
     if (tok == TOK_LAND) {
-        t = 0;
+        if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
-        save_regs(1);
+            CType ctb, cti;
-        for(;;) {
+            ctb.t = VT_BOOL;
-            t = gvtst(1, t);
+            cti.t = VT_INT;
-            if (tok != TOK_LAND) {
-                vseti(VT_JMPI, t);
-                break;
-            }
             next();
-            expr_or();
+            gen_cast(&ctb);
+            if (vtop->c.i) {
+                vpop();
+                expr_land();
+                gen_cast(&ctb);
+            } else {
+                expr_land();
+                vpop();
+            }
+            gen_cast(&cti);
+        } else {
+            int t = 0;
+            save_regs(1);
+            for(;;) {
+                t = gvtst(1, t);
+                if (tok != TOK_LAND) {
+                    vseti(VT_JMPI, t);
+                    break;
+                }
+                next();
+                expr_or();
+            }
         }
     }
 }
 static void expr_lor(void)
 {
-    int t;
     expr_land();
     if (tok == TOK_LOR) {
-        t = 0;
+        if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {
-        save_regs(1);
+            CType ctb, cti;
-        for(;;) {
+            ctb.t = VT_BOOL;
-            t = gvtst(0, t);
+            cti.t = VT_INT;
-            if (tok != TOK_LOR) {
-                vseti(VT_JMP, t);
-                break;
-            }
             next();
-            expr_land();
+            gen_cast(&ctb);
+            if (vtop->c.i) {
+                expr_lor();
+                vpop();
+            } else {
+                vpop();
+                expr_lor();
+                gen_cast(&ctb);
+            }
+            gen_cast(&cti);
+        } else {
+            int t = 0;
+            save_regs(1);
+            for(;;) {
+                t = gvtst(0, t);
+                if (tok != TOK_LOR) {
+                    vseti(VT_JMP, t);
+                    break;
+                }
+                next();
+                expr_land();
+            }
         }
     }
 }
-/* XXX: better constant handling */
 static void expr_cond(void)
 {
     int tt, u, r1, r2, rc, t1, t2, bt1, bt2;
     SValue sv;
     CType type, type1, type2;
-    if (const_wanted)
+    expr_lor();
-        expr_lor_const();
-    else
-        expr_lor();
     if (tok == '?') {
         next();
         if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) == VT_CONST) {

tests/tests2/78_vla_label.c+5−1

 {
     goto start;
     {
-        int a[1 ? 1 : 1]; /* not a variable-length array */
+        int a[1 && 1]; /* not a variable-length array */
+        int b[1 || 1]; /* not a variable-length array */
+        int c[1 ? 1 : 1]; /* not a variable-length array */
     start:
         a[0] = 0;
+        b[0] = 0;
+        c[0] = 0;
     }
 }

Improve constant propagation with "&&" and "||".

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