tcg/optimize: Split out fold_call

Calls are special in that they have a variable number
of arguments, and need to be able to clobber globals.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/optimize.c

@@ -624,10 +624,42 @@ static void copy_propagate(OptContext *ctx, TCGOp *op,
     }
 }
 
+static bool fold_call(OptContext *ctx, TCGOp *op)
+{
+    TCGContext *s = ctx->tcg;
+    int nb_oargs = TCGOP_CALLO(op);
+    int nb_iargs = TCGOP_CALLI(op);
+    int flags, i;
+
+    init_arguments(ctx, op, nb_oargs + nb_iargs);
+    copy_propagate(ctx, op, nb_oargs, nb_iargs);
+
+    /* If the function reads or writes globals, reset temp data. */
+    flags = tcg_call_flags(op);
+    if (!(flags & (TCG_CALL_NO_READ_GLOBALS | TCG_CALL_NO_WRITE_GLOBALS))) {
+        int nb_globals = s->nb_globals;
+
+        for (i = 0; i < nb_globals; i++) {
+            if (test_bit(i, ctx->temps_used.l)) {
+                reset_ts(&ctx->tcg->temps[i]);
+            }
+        }
+    }
+
+    /* Reset temp data for outputs. */
+    for (i = 0; i < nb_oargs; i++) {
+        reset_temp(op->args[i]);
+    }
+
+    /* Stop optimizing MB across calls. */
+    ctx->prev_mb = NULL;
+    return true;
+}
+
 /* Propagate constants and copies, fold constant expressions. */
 void tcg_optimize(TCGContext *s)
 {
-    int nb_temps, nb_globals, i;
+    int nb_temps, i;
     TCGOp *op, *op_next;
     OptContext ctx = { .tcg = s };
 
@@ -637,8 +669,6 @@ void tcg_optimize(TCGContext *s)
        available through the doubly linked circular list. */
 
     nb_temps = s->nb_temps;
-    nb_globals = s->nb_globals;
-
     for (i = 0; i < nb_temps; ++i) {
         s->temps[i].state_ptr = NULL;
     }
@@ -647,17 +677,17 @@ void tcg_optimize(TCGContext *s)
         uint64_t z_mask, partmask, affected, tmp;
         int nb_oargs, nb_iargs;
         TCGOpcode opc = op->opc;
-        const TCGOpDef *def = &tcg_op_defs[opc];
+        const TCGOpDef *def;
 
-        /* Count the arguments, and initialize the temps that are
+        /* Calls are special. */
-           going to be used */
         if (opc == INDEX_op_call) {
-            nb_oargs = TCGOP_CALLO(op);
+            fold_call(&ctx, op);
-            nb_iargs = TCGOP_CALLI(op);
+            continue;
-        } else {
+        }
+
+        def = &tcg_op_defs[opc];
         nb_oargs = def->nb_oargs;
         nb_iargs = def->nb_iargs;
-        }
         init_arguments(&ctx, op, nb_oargs + nb_iargs);
         copy_propagate(&ctx, op, nb_oargs, nb_iargs);
 
@@ -1549,16 +1579,6 @@ void tcg_optimize(TCGContext *s)
         if (def->flags & TCG_OPF_BB_END) {
             memset(&ctx.temps_used, 0, sizeof(ctx.temps_used));
         } else {
-            if (opc == INDEX_op_call &&
-                !(tcg_call_flags(op)
-                  & (TCG_CALL_NO_READ_GLOBALS | TCG_CALL_NO_WRITE_GLOBALS))) {
-                for (i = 0; i < nb_globals; i++) {
-                    if (test_bit(i, ctx.temps_used.l)) {
-                        reset_ts(&s->temps[i]);
-                    }
-                }
-            }
-
             for (i = 0; i < nb_oargs; i++) {
                 reset_temp(op->args[i]);
                 /* Save the corresponding known-zero bits mask for the
@@ -1599,7 +1619,6 @@ void tcg_optimize(TCGContext *s)
             case INDEX_op_qemu_st_i32:
             case INDEX_op_qemu_st8_i32:
             case INDEX_op_qemu_st_i64:
-            case INDEX_op_call:
                 /* Opcodes that touch guest memory stop the optimization.  */
                 ctx.prev_mb = NULL;
                 break;