Mesa (master): i965: Fix regs read for FS_OPCODE_INTERP_PER_SLOT_OFFSET

[Chris Forbes]

Module: Mesa
Branch: master
Commit: 092c73a7c32b240a26ffeab2ee475f6d590540b2
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=092c73a7c32b240a26ffeab2ee475f6d590540b2

Author: Chris Forbes <chrisf at ijw.co.nz>
Date:   Sun Dec  7 10:12:36 2014 +1300

i965: Fix regs read for FS_OPCODE_INTERP_PER_SLOT_OFFSET

Dead code elimination was eating the Y offset.

Fixes the piglit test:
spec/ARB_gpu_shader5/arb_gpu_shader5-interpolateAtOffset-nonconst

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
Reviewed-by: Jason Ekstrand <jason.ekstrand at intel.com>

---

 src/mesa/drivers/dri/i965/brw_fs.cpp |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 37857e9..389c8ae 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -902,6 +902,8 @@ fs_inst::regs_read(fs_visitor *v, int arg) const
       return mlen;
    } else if (opcode == SHADER_OPCODE_UNTYPED_SURFACE_READ && arg == 0) {
       return mlen;
+   } else if (opcode == FS_OPCODE_INTERPOLATE_AT_PER_SLOT_OFFSET && arg == 0) {
+      return mlen;
    }
 
    switch (src[arg].file) {