8xx render: Add limited support for a8 dests.

This improves aa10text performance from 74k to 569k on my 855 laptop.
This also causes my 865 to hang on aa10text like it does on rgb10text,
thanks to actually hitting render accel.

1 files changed, 27 insertions, 13 deletions

diff --git a/src/i830_render.c b/src/i830_render.c
index c5196ccd..e4c46231 100644
--- a/src/i830_render.c
+++ b/src/i830_render.c
@@ -157,11 +157,9 @@ static Bool i830_get_dest_format(PicturePtr pDstPicture, uint32_t *dst_format)
     case PICT_x1r5g5b5:
         *dst_format = COLR_BUF_ARGB1555;
         break;
-	/*
     case PICT_a8:
         *dst_format = COLR_BUF_8BIT;
         break;
-	*/
     case PICT_a4r4g4b4:
     case PICT_x4r4g4b4:
 	*dst_format = COLR_BUF_ARGB4444;
@@ -175,8 +173,8 @@ static Bool i830_get_dest_format(PicturePtr pDstPicture, uint32_t *dst_format)
 }
 
 
-static uint32_t i830_get_blend_cntl(int op, PicturePtr pMask,
-				    uint32_t dst_format)
+static Bool i830_get_blend_cntl(ScrnInfoPtr pScrn, int op, PicturePtr pMask,
+				uint32_t dst_format, uint32_t *blendctl)
 {
     uint32_t sblend, dblend;
 
@@ -193,6 +191,14 @@ static uint32_t i830_get_blend_cntl(int op, PicturePtr pMask,
             sblend = BLENDFACTOR_ZERO;
     }
 
+    /* For blending purposes, COLR_BUF_8BIT values show up in the green
+     * channel.  So we can't use the alpha channel.
+     */
+    if (dst_format == PICT_a8 && ((sblend == BLENDFACTOR_DST_ALPHA ||
+				   sblend == BLENDFACTOR_INV_DST_ALPHA))) {
+	I830FALLBACK("Can't do dst alpha blending with PICT_a8 dest.\n");
+    }
+
     /* If the source alpha is being used, then we should only be in a case
      * where the source blend factor is 0, and the source blend value is the
      * mask channels multiplied by the source picture's alpha.
@@ -206,8 +212,10 @@ static uint32_t i830_get_blend_cntl(int op, PicturePtr pMask,
         }
     }
 
-    return (sblend << S8_SRC_BLEND_FACTOR_SHIFT) |
+    *blendctl = (sblend << S8_SRC_BLEND_FACTOR_SHIFT) |
 	(dblend << S8_DST_BLEND_FACTOR_SHIFT);
+
+    return TRUE;
 }
 
 static Bool i830_check_composite_texture(PicturePtr pPict, int unit)
@@ -449,13 +457,15 @@ i830_prepare_composite(int op, PicturePtr pSrcPicture,
 		 TB0A_OUTPUT_WRITE_CURRENT;
 
 	/* Get the source picture's channels into TBx_ARG1 */
-	if (pMaskPicture != NULL &&
-	    pMaskPicture->componentAlpha &&
-	    PICT_FORMAT_RGB(pMaskPicture->format) &&
-	    i830_blend_op[op].src_alpha)
+	if ((pMaskPicture != NULL &&
+	     pMaskPicture->componentAlpha &&
+	     PICT_FORMAT_RGB(pMaskPicture->format) &&
+	     i830_blend_op[op].src_alpha) || pDstPicture->format == PICT_a8)
 	{
 	    /* Producing source alpha value, so the first set of channels
-	     * is src.A instead of src.X
+	     * is src.A instead of src.X.  We also do this if the destination
+	     * is a8, in which case src.G is what's written, and the other
+	     * channels are ignored.
 	     */
 	    if (PICT_FORMAT_A(pSrcPicture->format) != 0) {
 		ablend |= TB0A_ARG1_SEL_TEXEL0;
@@ -477,8 +487,9 @@ i830_prepare_composite(int op, PicturePtr pSrcPicture,
 	}
 
 	if (pMask) {
-	    if (pMaskPicture->componentAlpha &&
-		PICT_FORMAT_RGB(pMaskPicture->format))
+	    if (pDstPicture->format != PICT_a8 &&
+		(pMaskPicture->componentAlpha &&
+		 PICT_FORMAT_RGB(pMaskPicture->format)))
 	    {
 		cblend |= TB0C_ARG2_SEL_TEXEL1;
 	    } else {
@@ -497,7 +508,10 @@ i830_prepare_composite(int op, PicturePtr pSrcPicture,
 	    ablend |= TB0A_ARG2_SEL_ONE;
 	}
 
-	blendctl = i830_get_blend_cntl(op, pMaskPicture, pDstPicture->format);
+	if (!i830_get_blend_cntl(pScrn, op, pMaskPicture, pDstPicture->format,
+				 &blendctl)) {
+	    return FALSE;
+	}
 
 	pI830->cblend = cblend;
 	pI830->ablend = ablend;