core vdp, minor fifo write optimisation

diff --git a/pico/videoport.c b/pico/videoport.c
index 6c99fcf..279347b 100644 (file)
--- a/pico/videoport.c
+++ b/pico/videoport.c
@@ -345,20 +345,18 @@ int PicoVideoFIFOWrite(int count, int flags, unsigned sr_mask,unsigned sr_flags)
   int burn = 0, x;\r
 \r
   // sync only needed if queue is too full or background dma might be deferred\r
-  if ((vf->fifo_ql >= 6) | (pv->status & SR_DMA))\r
+  if ((vf->fifo_ql >= 6) | (pv->status & PVS_DMABG))\r
     PicoVideoFIFOSync(lc);\r
-  pv->status = (pv->status & ~sr_mask) | sr_flags;\r
 \r
-  x = (vf->fifo_qx + vf->fifo_ql - 1) & 7;\r
-  if (unlikely(vf->fifo_queue[x] & FQ_BGDMA))\r
-    x = (x-1) & 7; // ignore bg dma ent (pushed back below if new ent created)\r
+  // determine last ent, ignoring bg dma (pushed back below if new ent created)\r
+  x = (vf->fifo_qx + vf->fifo_ql - 1 - !!(pv->status & PVS_DMABG)) & 7;\r
 \r
-  // determine queue position for entry\r
-  if (!(flags & FQ_BGDMA))\r
-    vf->fifo_total += count;\r
+  pv->status = (pv->status & ~sr_mask) | sr_flags;\r
+  vf->fifo_total += count * !(flags & FQ_BGDMA);\r
   if (!vf->fifo_ql)\r
     vf->fifo_slot = Cyc2Sl(vf, lc+7); // FIFO latency ~3 vdp slots\r
 \r
+  // determine queue position for entry\r
   count <<= (flags & FQ_BYTE)+3;\r
   if (vf->fifo_queue[x] && (vf->fifo_queue[x] & 7) == flags) {\r
     // amalgamate entries if of same type and not empty (in case of bgdma)\r