i965/fs: Add LINTERP's src0 to fs_inst::regs_read().

LINTERP's src0 is PLN's src1, and PLN's src1 reads exec_size / 4
registers.

Having that information lets us drop the delta_x/y special case code in
split_virtual_grfs().

Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 7cc88eade45482550875410286d457d826481d6d..5cdc19caab0123d50f39866723f7a0d4d5390fe7 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -953,6 +953,8 @@ fs_inst::regs_read(int arg) const
       return mlen;
    } else if (opcode == FS_OPCODE_INTERPOLATE_AT_PER_SLOT_OFFSET && arg == 0) {
       return mlen;
+   } else if (opcode == FS_OPCODE_LINTERP && arg == 0) {
+      return exec_size / 4;
    }
 
    switch (src[arg].file) {
@@ -1984,17 +1986,6 @@ fs_visitor::split_virtual_grfs()
       }
    }
 
-   if (brw->has_pln &&
-       this->delta_x[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC].file == GRF) {
-      /* PLN opcodes rely on the delta_xy being contiguous.  We only have to
-       * check this for BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC, because prior to
-       * Gen6, that was the only supported interpolation mode, and since Gen6,
-       * delta_x and delta_y are in fixed hardware registers.
-       */
-      int vgrf = this->delta_x[BRW_WM_PERSPECTIVE_PIXEL_BARYCENTRIC].reg;
-      split_points[vgrf_to_reg[vgrf] + 1] = false;
-   }
-
    foreach_block_and_inst(block, fs_inst, inst, cfg) {
       if (inst->dst.file == GRF) {
          int reg = vgrf_to_reg[inst->dst.reg] + inst->dst.reg_offset;