tcg/optimize: Change fail return for do_constant_folding_cond*

Return -1 instead of 2 for failure, so that we can
use comparisons against 0 for all cases.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 74 insertions, 71 deletions

diff --git a/tcg/optimize.c b/tcg/optimize.c
index 77cdffa..19c0168 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -502,10 +502,12 @@ static bool do_constant_folding_cond_eq(TCGCond c)
     }
 }
 
-/* Return 2 if the condition can't be simplified, and the result
-   of the condition (0 or 1) if it can */
-static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x,
-                                       TCGArg y, TCGCond c)
+/*
+ * Return -1 if the condition can't be simplified,
+ * and the result of the condition (0 or 1) if it can.
+ */
+static int do_constant_folding_cond(TCGOpcode op, TCGArg x,
+                                    TCGArg y, TCGCond c)
 {
     uint64_t xv = arg_info(x)->val;
     uint64_t yv = arg_info(y)->val;
@@ -527,15 +529,17 @@ static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x,
         case TCG_COND_GEU:
             return 1;
         default:
-            return 2;
+            return -1;
         }
     }
-    return 2;
+    return -1;
 }
 
-/* Return 2 if the condition can't be simplified, and the result
-   of the condition (0 or 1) if it can */
-static TCGArg do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c)
+/*
+ * Return -1 if the condition can't be simplified,
+ * and the result of the condition (0 or 1) if it can.
+ */
+static int do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c)
 {
     TCGArg al = p1[0], ah = p1[1];
     TCGArg bl = p2[0], bh = p2[1];
@@ -565,7 +569,7 @@ static TCGArg do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c)
     if (args_are_copies(al, bl) && args_are_copies(ah, bh)) {
         return do_constant_folding_cond_eq(c);
     }
-    return 2;
+    return -1;
 }
 
 static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2)
@@ -1321,22 +1325,21 @@ void tcg_optimize(TCGContext *s)
             break;
 
         CASE_OP_32_64(setcond):
-            tmp = do_constant_folding_cond(opc, op->args[1],
-                                           op->args[2], op->args[3]);
-            if (tmp != 2) {
-                tcg_opt_gen_movi(&ctx, op, op->args[0], tmp);
+            i = do_constant_folding_cond(opc, op->args[1],
+                                         op->args[2], op->args[3]);
+            if (i >= 0) {
+                tcg_opt_gen_movi(&ctx, op, op->args[0], i);
                 continue;
             }
             break;
 
         CASE_OP_32_64(brcond):
-            tmp = do_constant_folding_cond(opc, op->args[0],
-                                           op->args[1], op->args[2]);
-            switch (tmp) {
-            case 0:
+            i = do_constant_folding_cond(opc, op->args[0],
+                                         op->args[1], op->args[2]);
+            if (i == 0) {
                 tcg_op_remove(s, op);
                 continue;
-            case 1:
+            } else if (i > 0) {
                 memset(&ctx.temps_used, 0, sizeof(ctx.temps_used));
                 op->opc = opc = INDEX_op_br;
                 op->args[0] = op->args[3];
@@ -1345,10 +1348,10 @@ void tcg_optimize(TCGContext *s)
             break;
 
         CASE_OP_32_64(movcond):
-            tmp = do_constant_folding_cond(opc, op->args[1],
-                                           op->args[2], op->args[5]);
-            if (tmp != 2) {
-                tcg_opt_gen_mov(&ctx, op, op->args[0], op->args[4-tmp]);
+            i = do_constant_folding_cond(opc, op->args[1],
+                                         op->args[2], op->args[5]);
+            if (i >= 0) {
+                tcg_opt_gen_mov(&ctx, op, op->args[0], op->args[4 - i]);
                 continue;
             }
             if (arg_is_const(op->args[3]) && arg_is_const(op->args[4])) {
@@ -1412,14 +1415,14 @@ void tcg_optimize(TCGContext *s)
             break;
 
         case INDEX_op_brcond2_i32:
-            tmp = do_constant_folding_cond2(&op->args[0], &op->args[2],
-                                            op->args[4]);
-            if (tmp == 0) {
+            i = do_constant_folding_cond2(&op->args[0], &op->args[2],
+                                          op->args[4]);
+            if (i == 0) {
             do_brcond_false:
                 tcg_op_remove(s, op);
                 continue;
             }
-            if (tmp == 1) {
+            if (i > 0) {
             do_brcond_true:
                 op->opc = opc = INDEX_op_br;
                 op->args[0] = op->args[5];
@@ -1443,20 +1446,20 @@ void tcg_optimize(TCGContext *s)
             if (op->args[4] == TCG_COND_EQ) {
                 /* Simplify EQ comparisons where one of the pairs
                    can be simplified.  */
-                tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
-                                               op->args[0], op->args[2],
-                                               TCG_COND_EQ);
-                if (tmp == 0) {
+                i = do_constant_folding_cond(INDEX_op_brcond_i32,
+                                             op->args[0], op->args[2],
+                                             TCG_COND_EQ);
+                if (i == 0) {
                     goto do_brcond_false;
-                } else if (tmp == 1) {
+                } else if (i > 0) {
                     goto do_brcond_high;
                 }
-                tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
-                                               op->args[1], op->args[3],
-                                               TCG_COND_EQ);
-                if (tmp == 0) {
+                i = do_constant_folding_cond(INDEX_op_brcond_i32,
+                                             op->args[1], op->args[3],
+                                             TCG_COND_EQ);
+                if (i == 0) {
                     goto do_brcond_false;
-                } else if (tmp != 1) {
+                } else if (i < 0) {
                     break;
                 }
             do_brcond_low:
@@ -1470,31 +1473,31 @@ void tcg_optimize(TCGContext *s)
             if (op->args[4] == TCG_COND_NE) {
                 /* Simplify NE comparisons where one of the pairs
                    can be simplified.  */
-                tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
-                                               op->args[0], op->args[2],
-                                               TCG_COND_NE);
-                if (tmp == 0) {
+                i = do_constant_folding_cond(INDEX_op_brcond_i32,
+                                             op->args[0], op->args[2],
+                                             TCG_COND_NE);
+                if (i == 0) {
                     goto do_brcond_high;
-                } else if (tmp == 1) {
+                } else if (i > 0) {
                     goto do_brcond_true;
                 }
-                tmp = do_constant_folding_cond(INDEX_op_brcond_i32,
-                                               op->args[1], op->args[3],
-                                               TCG_COND_NE);
-                if (tmp == 0) {
+                i = do_constant_folding_cond(INDEX_op_brcond_i32,
+                                             op->args[1], op->args[3],
+                                             TCG_COND_NE);
+                if (i == 0) {
                     goto do_brcond_low;
-                } else if (tmp == 1) {
+                } else if (i > 0) {
                     goto do_brcond_true;
                 }
             }
             break;
 
         case INDEX_op_setcond2_i32:
-            tmp = do_constant_folding_cond2(&op->args[1], &op->args[3],
-                                            op->args[5]);
-            if (tmp != 2) {
+            i = do_constant_folding_cond2(&op->args[1], &op->args[3],
+                                          op->args[5]);
+            if (i >= 0) {
             do_setcond_const:
-                tcg_opt_gen_movi(&ctx, op, op->args[0], tmp);
+                tcg_opt_gen_movi(&ctx, op, op->args[0], i);
                 continue;
             }
             if ((op->args[5] == TCG_COND_LT || op->args[5] == TCG_COND_GE)
@@ -1516,20 +1519,20 @@ void tcg_optimize(TCGContext *s)
             if (op->args[5] == TCG_COND_EQ) {
                 /* Simplify EQ comparisons where one of the pairs
                    can be simplified.  */
-                tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
-                                               op->args[1], op->args[3],
-                                               TCG_COND_EQ);
-                if (tmp == 0) {
+                i = do_constant_folding_cond(INDEX_op_setcond_i32,
+                                             op->args[1], op->args[3],
+                                             TCG_COND_EQ);
+                if (i == 0) {
                     goto do_setcond_const;
-                } else if (tmp == 1) {
+                } else if (i > 0) {
                     goto do_setcond_high;
                 }
-                tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
-                                               op->args[2], op->args[4],
-                                               TCG_COND_EQ);
-                if (tmp == 0) {
+                i = do_constant_folding_cond(INDEX_op_setcond_i32,
+                                             op->args[2], op->args[4],
+                                             TCG_COND_EQ);
+                if (i == 0) {
                     goto do_setcond_high;
-                } else if (tmp != 1) {
+                } else if (i < 0) {
                     break;
                 }
             do_setcond_low:
@@ -1543,20 +1546,20 @@ void tcg_optimize(TCGContext *s)
             if (op->args[5] == TCG_COND_NE) {
                 /* Simplify NE comparisons where one of the pairs
                    can be simplified.  */
-                tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
-                                               op->args[1], op->args[3],
-                                               TCG_COND_NE);
-                if (tmp == 0) {
+                i = do_constant_folding_cond(INDEX_op_setcond_i32,
+                                             op->args[1], op->args[3],
+                                             TCG_COND_NE);
+                if (i == 0) {
                     goto do_setcond_high;
-                } else if (tmp == 1) {
+                } else if (i > 0) {
                     goto do_setcond_const;
                 }
-                tmp = do_constant_folding_cond(INDEX_op_setcond_i32,
-                                               op->args[2], op->args[4],
-                                               TCG_COND_NE);
-                if (tmp == 0) {
+                i = do_constant_folding_cond(INDEX_op_setcond_i32,
+                                             op->args[2], op->args[4],
+                                             TCG_COND_NE);
+                if (i == 0) {
                     goto do_setcond_low;
-                } else if (tmp == 1) {
+                } else if (i > 0) {
                     goto do_setcond_const;
                 }
             }