tcg/optimize: Split out fold_xi_to_i

Pull the "op r, a, 0 => movi r, 0" optimization into a function,
and use it in the outer opcode fold functions.

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, 20 insertions, 18 deletions

diff --git a/tcg/optimize.c b/tcg/optimize.c
index ab96849..cfdc53c 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -695,6 +695,15 @@ static bool fold_const2(OptContext *ctx, TCGOp *op)
     return false;
 }
 
+/* If the binary operation has second argument @i, fold to @i. */
+static bool fold_xi_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
+{
+    if (arg_is_const(op->args[2]) && arg_info(op->args[2])->val == i) {
+        return tcg_opt_gen_movi(ctx, op, op->args[0], i);
+    }
+    return false;
+}
+
 /* If the binary operation has both arguments equal, fold to @i. */
 static bool fold_xx_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
 {
@@ -763,6 +772,7 @@ static bool fold_add2_i32(OptContext *ctx, TCGOp *op)
 static bool fold_and(OptContext *ctx, TCGOp *op)
 {
     if (fold_const2(ctx, op) ||
+        fold_xi_to_i(ctx, op, 0) ||
         fold_xx_to_x(ctx, op)) {
         return true;
     }
@@ -1081,12 +1091,20 @@ static bool fold_movcond(OptContext *ctx, TCGOp *op)
 
 static bool fold_mul(OptContext *ctx, TCGOp *op)
 {
-    return fold_const2(ctx, op);
+    if (fold_const2(ctx, op) ||
+        fold_xi_to_i(ctx, op, 0)) {
+        return true;
+    }
+    return false;
 }
 
 static bool fold_mul_highpart(OptContext *ctx, TCGOp *op)
 {
-    return fold_const2(ctx, op);
+    if (fold_const2(ctx, op) ||
+        fold_xi_to_i(ctx, op, 0)) {
+        return true;
+    }
+    return false;
 }
 
 static bool fold_mulu2_i32(OptContext *ctx, TCGOp *op)
@@ -1753,22 +1771,6 @@ void tcg_optimize(TCGContext *s)
             continue;
         }
 
-        /* Simplify expression for "op r, a, 0 => movi r, 0" cases */
-        switch (opc) {
-        CASE_OP_32_64_VEC(and):
-        CASE_OP_32_64_VEC(mul):
-        CASE_OP_32_64(muluh):
-        CASE_OP_32_64(mulsh):
-            if (arg_is_const(op->args[2])
-                && arg_info(op->args[2])->val == 0) {
-                tcg_opt_gen_movi(&ctx, op, op->args[0], 0);
-                continue;
-            }
-            break;
-        default:
-            break;
-        }
-
         /*
          * Process each opcode.
          * Sorted alphabetically by opcode as much as possible.