Mesa (master): gallivm: fix tex offsets with mirror repeat linear

[Roland Scheidegger]

Module: Mesa
Branch: master
Commit: 205a3ce5c158349dda7082f44e95301526b9f183
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=205a3ce5c158349dda7082f44e95301526b9f183

Author: Roland Scheidegger <sroland at vmware.com>
Date:   Thu Oct 22 23:58:50 2015 +0200

gallivm: fix tex offsets with mirror repeat linear

Can't see why anyone would ever want to use this, but it was clearly broken.
This fixes the piglit texwrap offset test using this combination.

Reviewed-by: Dave Airlie <airlied at redhat.com>
Reviewed-by: Jose Fonseca <jfonseca at vmware.com>

---

 src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index 125505e..26bfa0d 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -405,16 +405,17 @@ lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
       break;
 
    case PIPE_TEX_WRAP_MIRROR_REPEAT:
+      if (offset) {
+         offset = lp_build_int_to_float(coord_bld, offset);
+         offset = lp_build_div(coord_bld, offset, length_f);
+         coord = lp_build_add(coord_bld, coord, offset);
+      }
       /* compute mirror function */
       coord = lp_build_coord_mirror(bld, coord);
 
       /* scale coord to length */
       coord = lp_build_mul(coord_bld, coord, length_f);
       coord = lp_build_sub(coord_bld, coord, half);
-      if (offset) {
-         offset = lp_build_int_to_float(coord_bld, offset);
-         coord = lp_build_add(coord_bld, coord, offset);
-      }
 
       /* convert to int, compute lerp weight */
       lp_build_ifloor_fract(coord_bld, coord, &coord0, &weight);