From: Richard Henderson <richard.henderson@linaro.org>
Date: Mon, 9 Dec 2024 02:47:59 +0000 (-0600)
Subject: tcg/optimize: Distinguish simplification in fold_setcond_zmask
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=95eb229363f28aaacf506974cdb3047d816345fe;p=qemu.git

tcg/optimize: Distinguish simplification in fold_setcond_zmask

Change return from bool to int; distinguish between
complete folding, simplification, and no change.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---

diff --git a/tcg/optimize.c b/tcg/optimize.c
index e78f5a79a3..678015a94a 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -2155,7 +2155,8 @@ static bool fold_remainder(OptContext *ctx, TCGOp *op)
     return finish_folding(ctx, op);
 }
 
-static bool fold_setcond_zmask(OptContext *ctx, TCGOp *op, bool neg)
+/* Return 1 if finished, -1 if simplified, 0 if unchanged. */
+static int fold_setcond_zmask(OptContext *ctx, TCGOp *op, bool neg)
 {
     uint64_t a_zmask, b_val;
     TCGCond cond;
@@ -2250,11 +2251,10 @@ static bool fold_setcond_zmask(OptContext *ctx, TCGOp *op, bool neg)
                 op->opc = xor_opc;
                 op->args[2] = arg_new_constant(ctx, 1);
             }
-            return false;
+            return -1;
         }
     }
-
-    return false;
+    return 0;
 }
 
 static void fold_setcond_tst_pow2(OptContext *ctx, TCGOp *op, bool neg)
@@ -2359,10 +2359,13 @@ static bool fold_setcond(OptContext *ctx, TCGOp *op)
         return tcg_opt_gen_movi(ctx, op, op->args[0], i);
     }
 
-    if (fold_setcond_zmask(ctx, op, false)) {
+    i = fold_setcond_zmask(ctx, op, false);
+    if (i > 0) {
         return true;
     }
-    fold_setcond_tst_pow2(ctx, op, false);
+    if (i == 0) {
+        fold_setcond_tst_pow2(ctx, op, false);
+    }
 
     ctx->z_mask = 1;
     return false;
@@ -2376,10 +2379,13 @@ static bool fold_negsetcond(OptContext *ctx, TCGOp *op)
         return tcg_opt_gen_movi(ctx, op, op->args[0], -i);
     }
 
-    if (fold_setcond_zmask(ctx, op, true)) {
+    i = fold_setcond_zmask(ctx, op, true);
+    if (i > 0) {
         return true;
     }
-    fold_setcond_tst_pow2(ctx, op, true);
+    if (i == 0) {
+        fold_setcond_tst_pow2(ctx, op, true);
+    }
 
     /* Value is {0,-1} so all bits are repetitions of the sign. */
     ctx->s_mask = -1;