<!-- GRAS registers -->
        <reg32 offset="0x2040" name="GRAS_CL_CLIP_CNTL">
-               <bitfield name="IJ_PERSP_CENTER" pos="12" type="boolean"/> <!-- is it more bits? -->
+               <bitfield name="IJ_PERSP_CENTER" pos="12" type="boolean"/>
+               <bitfield name="IJ_NON_PERSP_CENTER" pos="13" type="boolean"/>
+               <bitfield name="IJ_PERSP_CENTROID" pos="14" type="boolean"/>
+               <bitfield name="IJ_NON_PERSP_CENTROID" pos="15" type="boolean"/>
                <bitfield name="CLIP_DISABLE" pos="16" type="boolean"/>
                <bitfield name="ZFAR_CLIP_DISABLE" pos="17" type="boolean"/>
                <bitfield name="VP_CLIP_CODE_IGNORE" pos="19" type="boolean"/>
                <bitfield name="PRIMALLOCTHRESHOLD" low="26" high="31" type="uint"/>
        </reg32>
        <reg32 offset="0x2203" name="HLSQ_CONTROL_3_REG">
-               <!-- register loaded with position (bary.f, gl_FragCoord, etc) -->
-               <bitfield name="REGID" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJPERSPCENTERREGID" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJNONPERSPCENTERREGID" low="8" high="15" type="a3xx_regid"/>
+               <bitfield name="IJPERSPCENTROIDREGID" low="16" high="23" type="a3xx_regid"/>
+               <bitfield name="IJNONPERSPCENTROIDREGID" low="24" high="31" type="a3xx_regid"/>
        </reg32>
        <reg32 offset="0x2204" name="HLSQ_VS_CONTROL_REG" type="a3xx_hlsq_vs_fs_control_reg"/>
        <reg32 offset="0x2205" name="HLSQ_FS_CONTROL_REG" type="a3xx_hlsq_vs_fs_control_reg"/>
 
                <bitfield name="SAMPLEMASK_REGID" low="18" high="25" type="a3xx_regid"/>
        </reg32>
        <reg32 offset="0x23c3" name="HLSQ_CONTROL_3_REG">
-               <!-- register loaded with position (bary.f, gl_FragCoord, etc) -->
-               <bitfield name="REGID" low="0" high="7" type="a3xx_regid"/>
+               <!-- register loaded with position (bary.f) -->
+               <bitfield name="IJ_PERSP_PIXEL" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_PIXEL" low="8" high="15" type="a3xx_regid"/>
+               <bitfield name="IJ_PERSP_CENTROID" low="16" high="23" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_CENTROID" low="24" high="31" type="a3xx_regid"/>
        </reg32>
        <!-- 0x23c4 3 regids, lowest one goes to 0 when *not* per-sample shading -->
-       <reg32 offset="0x23c4" name="HLSQ_CONTROL_4_REG"/>
+       <reg32 offset="0xb985" name="HLSQ_CONTROL_4_REG">
+               <bitfield name="IJ_PERSP_SAMPLE" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_SAMPLE" low="8" high="15" type="a3xx_regid"/>
+       </reg32>
 
        <bitset name="a4xx_xs_control_reg" inline="yes">
                <bitfield name="CONSTLENGTH" low="0" high="7" type="uint"/>
 
        <reg32 offset="0xe004" name="UNKNOWN_E004"/> <!-- always 00000000? -->
        <reg32 offset="0xe005" name="GRAS_CNTL">
                <!-- see also RB_RENDER_CONTROL0 -->
-               <bitfield name="VARYING" pos="0" type="boolean"/>
+               <bitfield name="IJ_PERSP_PIXEL" pos="0" type="boolean"/>
+               <bitfield name="IJ_PERSP_CENTROID" pos="1" type="boolean"/>
+               <bitfield name="IJ_PERSP_SAMPLE" pos="2" type="boolean"/>
                <!--
                bit 3 set when blob turns on WCOORD.. which also corresponds to
                register being set in in HLSQ_CONTROL_3_REG bits 8..15 (which
                way??
                Also, when that happens, VARYING bits are turned on as well.
                 -->
-               <bitfield name="UNK3" pos="3" type="boolean"/>
+               <bitfield name="SIZE" pos="3" type="boolean"/>
                <bitfield name="COORD_MASK" low="6" high="9" type="hex"/>
        </reg32>
        <reg32 offset="0xe006" name="GRAS_CL_GUARDBAND_CLIP_ADJ">
         -->
        <reg32 offset="0xe144" name="RB_RENDER_CONTROL0">
                <!-- see also GRAS_CNTL -->
-               <bitfield name="VARYING" pos="0" type="boolean"/>
+               <bitfield name="IJ_PERSP_PIXEL" pos="0" type="boolean"/>
+               <bitfield name="IJ_PERSP_CENTROID" pos="1" type="boolean"/>
+               <bitfield name="IJ_PERSP_SAMPLE" pos="2" type="boolean"/>
                <!--
                bit 3 set when blob turns on WCOORD.. which also corresponds to
                register being set in in HLSQ_CONTROL_3_REG bits 8..15 (which
                way??
                Also, when that happens, VARYING bits are turned on as well.
                 -->
-               <bitfield name="UNK3" pos="3" type="boolean"/>
+               <bitfield name="SIZE" pos="3" type="boolean"/>
                <bitfield name="COORD_MASK" low="6" high="9" type="hex"/>
        </reg32>
        <reg32 offset="0xe145" name="RB_RENDER_CONTROL1">
                <!-- SAMPLEID is loaded into a half-precision register: -->
                <bitfield name="SAMPLEID" low="8" high="15" type="a3xx_regid"/>
                <bitfield name="SAMPLEMASK" low="16" high="23" type="a3xx_regid"/>
+               <bitfield name="SIZE" low="24" high="31" type="a3xx_regid"/>
        </reg32>
        <reg32 offset="0xe787" name="HLSQ_CONTROL_3_REG">
                <!-- register loaded with position (bary.f) -->
-               <bitfield name="FRAGCOORDXYREGID" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJ_PERSP_PIXEL" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_PIXEL" low="8" high="15" type="a3xx_regid"/>
+               <bitfield name="IJ_PERSP_CENTROID" low="16" high="23" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_CENTROID" low="24" high="31" type="a3xx_regid"/>
        </reg32>
        <reg32 offset="0xe788" name="HLSQ_CONTROL_4_REG">
+               <bitfield name="IJ_PERSP_SAMPLE" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_SAMPLE" low="8" high="15" type="a3xx_regid"/>
                <bitfield name="XYCOORDREGID" low="16" high="23" type="a3xx_regid"/>
                <bitfield name="ZWCOORDREGID" low="24" high="31" type="a3xx_regid"/>
        </reg32>
 
 
        <reg32 offset="0x8005" name="GRAS_CNTL">
                <!-- see also RB_RENDER_CONTROL0 -->
-               <bitfield name="VARYING" pos="0" type="boolean"/>
+               <bitfield name="IJ_PERSP_PIXEL" pos="0" type="boolean"/>
                <!-- b1 set for interpolateAtCentroid() -->
-               <bitfield name="CENTROID" pos="1" type="boolean"/>
+               <bitfield name="IJ_PERSP_CENTROID" pos="1" type="boolean"/>
                <!-- b2 set instead of b0 when running in per-sample mode -->
-               <bitfield name="PERSAMP_VARYING" pos="2" type="boolean"/>
+               <bitfield name="IJ_PERSP_SAMPLE" pos="2" type="boolean"/>
                <!--
                b3 set for interpolateAt{Offset,Sample}() if not in per-sample
                mode, and frag_face
         -->
        <reg32 offset="0x8809" name="RB_RENDER_CONTROL0">
                <!-- see also GRAS_CNTL -->
-               <bitfield name="VARYING" pos="0" type="boolean"/>
+               <bitfield name="IJ_PERSP_PIXEL" pos="0" type="boolean"/>
                <!-- b1 set for interpolateAtCentroid() -->
-               <bitfield name="CENTROID" pos="1" type="boolean"/>
+               <bitfield name="IJ_PERSP_CENTROID" pos="1" type="boolean"/>
                <!-- b2 set instead of b0 when running in per-sample mode -->
-               <bitfield name="PERSAMP_VARYING" pos="2" type="boolean"/>
+               <bitfield name="IJ_PERSP_SAMPLE" pos="2" type="boolean"/>
                <!--
                b3 set for interpolateAt{Offset,Sample}() if not in per-sample
                mode, and frag_face
        </reg32>
        <reg32 offset="0xb984" name="HLSQ_CONTROL_3_REG">
                <!-- register loaded with position (bary.f) -->
-               <bitfield name="BARY_IJ_PIXEL" low="0" high="7" type="a3xx_regid"/>
-               <bitfield name="BARY_IJ_CENTROID" low="16" high="23" type="a3xx_regid"/>
+               <bitfield name="IJ_PERSP_PIXEL" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_PIXEL" low="8" high="15" type="a3xx_regid"/>
+               <bitfield name="IJ_PERSP_CENTROID" low="16" high="23" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_CENTROID" low="24" high="31" type="a3xx_regid"/>
        </reg32>
        <reg32 offset="0xb985" name="HLSQ_CONTROL_4_REG">
-               <bitfield name="BARY_IJ_PIXEL_PERSAMP" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJ_PERSP_SAMPLE" low="0" high="7" type="a3xx_regid"/>
+               <bitfield name="IJ_LINEAR_SAMPLE" low="8" high="15" type="a3xx_regid"/>
                <bitfield name="XYCOORDREGID" low="16" high="23" type="a3xx_regid"/>
                <bitfield name="ZWCOORDREGID" low="24" high="31" type="a3xx_regid"/>
        </reg32>
 
                   A6XX_HLSQ_CONTROL_2_REG_SAMPLEID(samp_id_regid) |
                   A6XX_HLSQ_CONTROL_2_REG_SAMPLEMASK(smask_in_regid) |
                   A6XX_HLSQ_CONTROL_2_REG_SIZE(ij_size_regid));
-   tu_cs_emit(cs, A6XX_HLSQ_CONTROL_3_REG_BARY_IJ_PIXEL(ij_pix_regid) |
-                  A6XX_HLSQ_CONTROL_3_REG_BARY_IJ_CENTROID(ij_cent_regid) |
+   tu_cs_emit(cs, A6XX_HLSQ_CONTROL_3_REG_IJ_PERSP_PIXEL(ij_pix_regid) |
+                  A6XX_HLSQ_CONTROL_3_REG_IJ_PERSP_CENTROID(ij_cent_regid) |
                   0xfc00fc00);
    tu_cs_emit(cs, A6XX_HLSQ_CONTROL_4_REG_XYCOORDREGID(coord_regid) |
                   A6XX_HLSQ_CONTROL_4_REG_ZWCOORDREGID(zwcoord_regid) |
-                  A6XX_HLSQ_CONTROL_4_REG_BARY_IJ_PIXEL_PERSAMP(ij_samp_regid) |
+                  A6XX_HLSQ_CONTROL_4_REG_IJ_PERSP_SAMPLE(ij_samp_regid) |
                   0x0000fc00);
    tu_cs_emit(cs, 0xfc);
 
 
    tu_cs_emit_pkt4(cs, REG_A6XX_GRAS_CNTL, 1);
    tu_cs_emit(cs,
-         CONDREG(ij_pix_regid, A6XX_GRAS_CNTL_VARYING) |
-         CONDREG(ij_cent_regid, A6XX_GRAS_CNTL_CENTROID) |
-         CONDREG(ij_samp_regid, A6XX_GRAS_CNTL_PERSAMP_VARYING) |
+         CONDREG(ij_pix_regid, A6XX_GRAS_CNTL_IJ_PERSP_PIXEL) |
+         CONDREG(ij_cent_regid, A6XX_GRAS_CNTL_IJ_PERSP_CENTROID) |
+         CONDREG(ij_samp_regid, A6XX_GRAS_CNTL_IJ_PERSP_SAMPLE) |
          COND(VALIDREG(ij_size_regid) && !sample_shading, A6XX_GRAS_CNTL_SIZE) |
          COND(VALIDREG(ij_size_regid) &&  sample_shading, A6XX_GRAS_CNTL_SIZE_PERSAMP) |
          COND(fs->fragcoord_compmask != 0, A6XX_GRAS_CNTL_SIZE |
 
    tu_cs_emit_pkt4(cs, REG_A6XX_RB_RENDER_CONTROL0, 2);
    tu_cs_emit(cs,
-         CONDREG(ij_pix_regid, A6XX_RB_RENDER_CONTROL0_VARYING) |
-         CONDREG(ij_cent_regid, A6XX_RB_RENDER_CONTROL0_CENTROID) |
-         CONDREG(ij_samp_regid, A6XX_RB_RENDER_CONTROL0_PERSAMP_VARYING) |
+         CONDREG(ij_pix_regid, A6XX_RB_RENDER_CONTROL0_IJ_PERSP_PIXEL) |
+         CONDREG(ij_cent_regid, A6XX_RB_RENDER_CONTROL0_IJ_PERSP_CENTROID) |
+         CONDREG(ij_samp_regid, A6XX_RB_RENDER_CONTROL0_IJ_PERSP_SAMPLE) |
          COND(enable_varyings, A6XX_RB_RENDER_CONTROL0_UNK10) |
          COND(VALIDREG(ij_size_regid) && !sample_shading, A6XX_RB_RENDER_CONTROL0_SIZE) |
          COND(VALIDREG(ij_size_regid) &&  sample_shading, A6XX_RB_RENDER_CONTROL0_SIZE_PERSAMP) |
 
                        A3XX_HLSQ_CONTROL_1_REG_FRAGCOORDZWREGID(zwcoord_regid));
        OUT_RING(ring, A3XX_HLSQ_CONTROL_2_REG_PRIMALLOCTHRESHOLD(31) |
                        A3XX_HLSQ_CONTROL_2_REG_FACENESSREGID(face_regid));
-       OUT_RING(ring, A3XX_HLSQ_CONTROL_3_REG_REGID(vcoord_regid));
+       OUT_RING(ring, A3XX_HLSQ_CONTROL_3_REG_IJPERSPCENTERREGID(vcoord_regid));
        OUT_RING(ring, A3XX_HLSQ_VS_CONTROL_REG_CONSTLENGTH(vp->constlen) |
                        A3XX_HLSQ_VS_CONTROL_REG_CONSTSTARTOFFSET(0) |
                        A3XX_HLSQ_VS_CONTROL_REG_INSTRLENGTH(vpbuffersz));
 
        OUT_RING(ring, A4XX_HLSQ_CONTROL_2_REG_PRIMALLOCTHRESHOLD(63) |
                        0x3f3f000 |           /* XXX */
                        A4XX_HLSQ_CONTROL_2_REG_FACEREGID(face_regid));
-       OUT_RING(ring, A4XX_HLSQ_CONTROL_3_REG_REGID(vcoord_regid) |
+       OUT_RING(ring, A4XX_HLSQ_CONTROL_3_REG_IJ_PERSP_PIXEL(vcoord_regid) |
                        0xfcfcfc00);
        OUT_RING(ring, 0x00fcfcfc);   /* XXX HLSQ_CONTROL_4 */
 
 
                        A5XX_HLSQ_CONTROL_2_REG_SAMPLEID(samp_id_regid) |
                        A5XX_HLSQ_CONTROL_2_REG_SAMPLEMASK(samp_mask_regid) |
                        0xfc000000);               /* XXX */
-       OUT_RING(ring, A5XX_HLSQ_CONTROL_3_REG_FRAGCOORDXYREGID(vcoord_regid) |
+       OUT_RING(ring, A5XX_HLSQ_CONTROL_3_REG_IJ_PERSP_PIXEL(vcoord_regid) |
                        0xfcfcfc00);               /* XXX */
        OUT_RING(ring, A5XX_HLSQ_CONTROL_4_REG_XYCOORDREGID(coord_regid) |
                        A5XX_HLSQ_CONTROL_4_REG_ZWCOORDREGID(zwcoord_regid) |
        OUT_RING(ring, 0x00000010);        /* XXX */
 
        OUT_PKT4(ring, REG_A5XX_GRAS_CNTL, 1);
-       OUT_RING(ring, COND(s[FS].v->total_in > 0, A5XX_GRAS_CNTL_VARYING) |
+       OUT_RING(ring, COND(s[FS].v->total_in > 0, A5XX_GRAS_CNTL_IJ_PERSP_PIXEL) |
                        COND(s[FS].v->fragcoord_compmask != 0,
                                        A5XX_GRAS_CNTL_COORD_MASK(s[FS].v->fragcoord_compmask) |
-                                       A5XX_GRAS_CNTL_UNK3) |
-                       COND(s[FS].v->frag_face, A5XX_GRAS_CNTL_UNK3));
+                                       A5XX_GRAS_CNTL_SIZE) |
+                       COND(s[FS].v->frag_face, A5XX_GRAS_CNTL_SIZE));
 
        OUT_PKT4(ring, REG_A5XX_RB_RENDER_CONTROL0, 2);
-       OUT_RING(ring, COND(s[FS].v->total_in > 0, A5XX_RB_RENDER_CONTROL0_VARYING) |
+       OUT_RING(ring, COND(s[FS].v->total_in > 0, A5XX_RB_RENDER_CONTROL0_IJ_PERSP_PIXEL) |
                        COND(s[FS].v->fragcoord_compmask != 0,
                                        A5XX_RB_RENDER_CONTROL0_COORD_MASK(s[FS].v->fragcoord_compmask) |
-                                       A5XX_RB_RENDER_CONTROL0_UNK3) |
-                       COND(s[FS].v->frag_face, A5XX_RB_RENDER_CONTROL0_UNK3));
+                                       A5XX_RB_RENDER_CONTROL0_SIZE) |
+                       COND(s[FS].v->frag_face, A5XX_RB_RENDER_CONTROL0_SIZE));
        OUT_RING(ring,
                        COND(samp_mask_regid != regid(63, 0),
                                A5XX_RB_RENDER_CONTROL1_SAMPLEMASK) |
 
                         A6XX_HLSQ_CONTROL_2_REG_SAMPLEID(samp_id_regid) |
                         A6XX_HLSQ_CONTROL_2_REG_SAMPLEMASK(smask_in_regid) |
                         A6XX_HLSQ_CONTROL_2_REG_SIZE(ij_size_regid));
-       OUT_RING(ring, A6XX_HLSQ_CONTROL_3_REG_BARY_IJ_PIXEL(ij_pix_regid) |
-                        A6XX_HLSQ_CONTROL_3_REG_BARY_IJ_CENTROID(ij_cent_regid) |
+       OUT_RING(ring, A6XX_HLSQ_CONTROL_3_REG_IJ_PERSP_PIXEL(ij_pix_regid) |
+                        A6XX_HLSQ_CONTROL_3_REG_IJ_PERSP_CENTROID(ij_cent_regid) |
                         0xfc00fc00);               /* XXX */
        OUT_RING(ring, A6XX_HLSQ_CONTROL_4_REG_XYCOORDREGID(coord_regid) |
                         A6XX_HLSQ_CONTROL_4_REG_ZWCOORDREGID(zwcoord_regid) |
-                        A6XX_HLSQ_CONTROL_4_REG_BARY_IJ_PIXEL_PERSAMP(ij_samp_regid) |
+                        A6XX_HLSQ_CONTROL_4_REG_IJ_PERSP_SAMPLE(ij_samp_regid) |
                         0x0000fc00);               /* XXX */
        OUT_RING(ring, 0xfc);              /* XXX */
 
 
        OUT_PKT4(ring, REG_A6XX_GRAS_CNTL, 1);
        OUT_RING(ring,
-                       CONDREG(ij_pix_regid, A6XX_GRAS_CNTL_VARYING) |
-                       CONDREG(ij_cent_regid, A6XX_GRAS_CNTL_CENTROID) |
-                       CONDREG(ij_samp_regid, A6XX_GRAS_CNTL_PERSAMP_VARYING) |
+                       CONDREG(ij_pix_regid, A6XX_GRAS_CNTL_IJ_PERSP_PIXEL) |
+                       CONDREG(ij_cent_regid, A6XX_GRAS_CNTL_IJ_PERSP_CENTROID) |
+                       CONDREG(ij_samp_regid, A6XX_GRAS_CNTL_IJ_PERSP_SAMPLE) |
                        COND(VALIDREG(ij_size_regid) && !sample_shading, A6XX_GRAS_CNTL_SIZE) |
                        COND(VALIDREG(ij_size_regid) &&  sample_shading, A6XX_GRAS_CNTL_SIZE_PERSAMP) |
                        COND(fs->fragcoord_compmask != 0, A6XX_GRAS_CNTL_SIZE |
 
        OUT_PKT4(ring, REG_A6XX_RB_RENDER_CONTROL0, 2);
        OUT_RING(ring,
-                       CONDREG(ij_pix_regid, A6XX_RB_RENDER_CONTROL0_VARYING) |
-                       CONDREG(ij_cent_regid, A6XX_RB_RENDER_CONTROL0_CENTROID) |
-                       CONDREG(ij_samp_regid, A6XX_RB_RENDER_CONTROL0_PERSAMP_VARYING) |
+                       CONDREG(ij_pix_regid, A6XX_RB_RENDER_CONTROL0_IJ_PERSP_PIXEL) |
+                       CONDREG(ij_cent_regid, A6XX_RB_RENDER_CONTROL0_IJ_PERSP_CENTROID) |
+                       CONDREG(ij_samp_regid, A6XX_RB_RENDER_CONTROL0_IJ_PERSP_SAMPLE) |
                        COND(enable_varyings, A6XX_RB_RENDER_CONTROL0_UNK10) |
                        COND(VALIDREG(ij_size_regid) && !sample_shading, A6XX_RB_RENDER_CONTROL0_SIZE) |
                        COND(VALIDREG(ij_size_regid) &&  sample_shading, A6XX_RB_RENDER_CONTROL0_SIZE_PERSAMP) |