Commit f7c62771e6 for qemu.org

commit f7c62771e6b88bd256d4b4ec71a53d5245f0fa8a
Author: Richard Henderson <richard.henderson@linaro.org>
Date:   Wed May 20 14:51:38 2026 +0200

    tcg: Massage fold_multiply2()

    In order to ease next commit review, check arg2 constness
    in the inner loop.

    Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
    Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
    Message-ID: <20260520125139.13352-2-philmd@linaro.org>

diff --git a/tcg/optimize.c b/tcg/optimize.c
index b1abec69a5..ef5eb2cf17 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -2173,45 +2173,45 @@ static bool fold_multiply2(OptContext *ctx, TCGOp *op)
 {
     swap_commutative(op->args[0], &op->args[2], &op->args[3]);

-    if (arg_is_const(op->args[2]) && arg_is_const(op->args[3])) {
-        uint64_t a = arg_const_val(op->args[2]);
+    if (arg_is_const(op->args[3])) {
         uint64_t b = arg_const_val(op->args[3]);
-        uint64_t h, l;
-        TCGArg rl, rh;
+        TCGArg rl = op->args[0];
+        TCGArg rh = op->args[1];
         TCGOp *op2;

-        switch (op->opc) {
-        case INDEX_op_mulu2:
-            if (ctx->type == TCG_TYPE_I32) {
-                l = (uint64_t)(uint32_t)a * (uint32_t)b;
-                h = (int32_t)(l >> 32);
-                l = (int32_t)l;
-            } else {
-                mulu64(&l, &h, a, b);
-            }
-            break;
-        case INDEX_op_muls2:
-            if (ctx->type == TCG_TYPE_I32) {
-                l = (int64_t)(int32_t)a * (int32_t)b;
-                h = l >> 32;
-                l = (int32_t)l;
-            } else {
-                muls64(&l, &h, a, b);
+        if (arg_is_const(op->args[2])) {
+            uint64_t a = arg_const_val(op->args[2]);
+            uint64_t h, l;
+
+            switch (op->opc) {
+            case INDEX_op_mulu2:
+                if (ctx->type == TCG_TYPE_I32) {
+                    l = (uint64_t)(uint32_t)a * (uint32_t)b;
+                    h = (int32_t)(l >> 32);
+                    l = (int32_t)l;
+                } else {
+                    mulu64(&l, &h, a, b);
+                }
+                break;
+            case INDEX_op_muls2:
+                if (ctx->type == TCG_TYPE_I32) {
+                    l = (int64_t)(int32_t)a * (int32_t)b;
+                    h = l >> 32;
+                    l = (int32_t)l;
+                } else {
+                    muls64(&l, &h, a, b);
+                }
+                break;
+            default:
+                g_assert_not_reached();
             }
-            break;
-        default:
-            g_assert_not_reached();
-        }
-
-        rl = op->args[0];
-        rh = op->args[1];

-        /* The proper opcode is supplied by tcg_opt_gen_mov. */
-        op2 = opt_insert_before(ctx, op, 0, 2);
-
-        tcg_opt_gen_movi(ctx, op, rl, l);
-        tcg_opt_gen_movi(ctx, op2, rh, h);
-        return true;
+            /* The proper opcode is supplied by tcg_opt_gen_mov. */
+            op2 = opt_insert_before(ctx, op, 0, 2);
+            tcg_opt_gen_movi(ctx, op, rl, l);
+            tcg_opt_gen_movi(ctx, op2, rh, h);
+            return true;
+        }
     }
     return finish_folding(ctx, op);
 }