diff options
Diffstat (limited to 'src/mesa/drivers/dri/i965/brw_vs_emit.c')
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_vs_emit.c | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_vs_emit.c b/src/mesa/drivers/dri/i965/brw_vs_emit.c index 5d22d548f3..2c18113ceb 100644 --- a/src/mesa/drivers/dri/i965/brw_vs_emit.c +++ b/src/mesa/drivers/dri/i965/brw_vs_emit.c @@ -238,12 +238,25 @@ static void brw_vs_alloc_regs( struct brw_vs_compile *c ) mrf++; /* just a placeholder? XXX fix later stages & remove this */ } else { - if (mrf < 16) { + /* Two restrictions on our compute-to-MRF here. The + * message length for all SEND messages is restricted to + * [1,15], so we can't use mrf 15, as that means a length + * of 16. + * + * Additionally, URB writes are aligned to URB rows, so we + * need to put an even number of registers of URB data in + * each URB write so that the later write is aligned. A + * message length of 15 means 1 message header reg plus 14 + * regs of URB data. + * + * For attributes beyond the compute-to-MRF, we compute to + * GRFs and they will be written in the second URB_WRITE. + */ + if (mrf < 15) { c->regs[PROGRAM_OUTPUT][i] = brw_message_reg(mrf); mrf++; } else { - /* too many vertex results to fit in MRF, use GRF for overflow */ if (!c->first_overflow_output) c->first_overflow_output = i; c->regs[PROGRAM_OUTPUT][i] = brw_vec8_grf(reg, 0); @@ -1426,29 +1439,26 @@ static void emit_vertex_write( struct brw_vs_compile *c) * Move the overflowed attributes from the GRF to the MRF and * issue another brw_urb_WRITE(). */ - /* XXX I'm not 100% sure about which MRF regs to use here. Starting - * at mrf[4] atm... - */ - GLuint i, mrf = 0; + GLuint i, mrf = 1; for (i = c->first_overflow_output; i < VERT_RESULT_MAX; i++) { if (c->prog_data.outputs_written & BITFIELD64_BIT(i)) { /* move from GRF to MRF */ - brw_MOV(p, brw_message_reg(4+mrf), c->regs[PROGRAM_OUTPUT][i]); + brw_MOV(p, brw_message_reg(mrf), c->regs[PROGRAM_OUTPUT][i]); mrf++; } } brw_urb_WRITE(p, brw_null_reg(), /* dest */ - 4, /* starting mrf reg nr */ + 0, /* starting mrf reg nr */ c->r0, /* src */ 0, /* allocate */ 1, /* used */ - mrf+1, /* msg len */ + mrf, /* msg len */ 0, /* response len */ 1, /* eot */ 1, /* writes complete */ - BRW_MAX_MRF-1, /* urb destination offset */ + 14 / 2, /* urb destination offset */ BRW_URB_SWIZZLE_INTERLEAVE); } } |