[Stable-9.1.1 36/49] tcg/ppc: Use TCG_REG_TMP2 for scratch index in prepare_host_addr

[Michael Tokarev]

From: Richard Henderson <richard.henderson@linaro.org>

In tcg_out_qemu_ldst_i128, we need a non-zero index register,
which we then use as a base register in several address modes.
Since we always have TCG_REG_TMP2 available, use that.

Cc: qemu-stable@nongnu.org
Fixes: 526cd4ec01f ("tcg/ppc: Support 128-bit load/store")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2597
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-By: Michael Tokarev <mjt@tls.msk.ru>
(cherry picked from commit 3213da7b9539581c6df95f8ced5b09d0b02d425f)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/tcg/ppc/tcg-target.c.inc b/tcg/ppc/tcg-target.c.inc
index 69abd30bbb..deb80521b3 100644
--- a/tcg/ppc/tcg-target.c.inc
+++ b/tcg/ppc/tcg-target.c.inc
@@ -2617,8 +2617,8 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, 
HostAddress *h,
 
     if (TCG_TARGET_REG_BITS == 64 && addr_type == TCG_TYPE_I32) {
         /* Zero-extend the guest address for use in the host address. */
-        tcg_out_ext32u(s, TCG_REG_R0, addrlo);
-        h->index = TCG_REG_R0;
+        tcg_out_ext32u(s, TCG_REG_TMP2, addrlo);
+        h->index = TCG_REG_TMP2;
     } else {
         h->index = addrlo;
     }
-- 
2.39.5