[PATCH] tcg: Reset free_temps before tcg_optimize

[Richard Henderson]

When allocating new temps during tcg_optmize, do not re-use
any EBB temps that were used within the TB.  We do not have
any idea what span of the TB in which the temp was live.

Cc: qemu-stable@nongnu.org
Fixes: fb04ab7ddd8 ("tcg/optimize: Lower TCG_COND_TST{EQ,NE} if unsupported")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2711
Reported-by: wannacu <wannacu2049@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---

Unless there's some other reason to spin an -rc4, this can wait
to be the first patch for 10.0.1.

r~

---
 tcg/tcg.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 0babae1b88..eece825e2e 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -6120,6 +6120,9 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb, 
uint64_t pc_start)
     }
 #endif
 
+    /* Do not reuse any EBB that may be allocated within the TB. */
+    memset(s->free_temps, 0, sizeof(s->free_temps));
+
     tcg_optimize(s);
 
     reachable_code_pass(s);
-- 
2.43.0