From 34aff3c2e065dc19fbd83eb7b4766776f73378ab Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Sat, 28 Oct 2023 03:37:23 +0000
Subject: [PATCH] tcg/aarch64: Generate CBNZ for TSTNE of UINT32_MAX
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... and the inverse, CBZ for TSTEQ.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/aarch64/tcg-target.c.inc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tcg/aarch64/tcg-target.c.inc b/tcg/aarch64/tcg-target.c.inc
index 36fc46ae93..dec8ecc1b6 100644
--- a/tcg/aarch64/tcg-target.c.inc
+++ b/tcg/aarch64/tcg-target.c.inc
@@ -1463,6 +1463,12 @@ static void tcg_out_brcond(TCGContext *s, TCGType ext, TCGCond c, TCGArg a,
         break;
     case TCG_COND_TSTEQ:
     case TCG_COND_TSTNE:
+        /* tst xN,0xffffffff; b.ne L -> cbnz wN,L */
+        if (b_const && b == UINT32_MAX) {
+            ext = TCG_TYPE_I32;
+            need_cmp = false;
+            break;
+        }
         /* tst xN,1<<B; b.ne L -> tbnz xN,B,L */
         if (b_const && is_power_of_2(b)) {
             tbit = ctz64(b);