hw/audio/es1370: skip automatic zero-init of large array

The 'es1370_transfer_audio' method has a 4k byte array used for
copying data between the audio backend and device. Skip the automatic
zero-init of this array to eliminate the performance overhead in
the I/O hot path.

The 'tmpbuf' array will be fully initialized when reading data from
the audio backend and/or device memory.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20250610123709.835102-10-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

diff --git a/hw/audio/es1370.c b/hw/audio/es1370.c
index 8efb969212830f84b002f514de098c7c94282016..a6a32a6348bc02b87e125e153ac7f1fb48dfc1bc 100644 (file)
--- a/hw/audio/es1370.c
+++ b/hw/audio/es1370.c
@@ -604,7 +604,7 @@ static uint64_t es1370_read(void *opaque, hwaddr addr, unsigned size)
 static void es1370_transfer_audio (ES1370State *s, struct chan *d, int loop_sel,
                                    int max, bool *irq)
 {
-    uint8_t tmpbuf[4096];
+    QEMU_UNINITIALIZED uint8_t tmpbuf[4096];
     size_t to_transfer;
     uint32_t addr = d->frame_addr;
     int sc = d->scount & 0xffff;