intel/fs/validate: Assert SEND [extended] descriptors are uniform

This is required by code-gen since it generates a 1-wide OR and it'll
blow up if the register width > 1.  It's also way better than the "your
register is the wrong size" assert you get from the more generic
validation check.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21094>

src/intel/compiler/brw_fs_validate.cpp

@@ -87,7 +87,8 @@ fs_visitor::validate()
 {
 #ifndef NDEBUG
    foreach_block_and_inst (block, fs_inst, inst, cfg) {
-      if (inst->opcode == SHADER_OPCODE_URB_WRITE_LOGICAL) {
+      switch (inst->opcode) {
+      case SHADER_OPCODE_URB_WRITE_LOGICAL: {
          const unsigned header_size = 1 +
             unsigned(inst->src[URB_LOGICAL_SRC_PER_SLOT_OFFSETS].file != BAD_FILE) +
             unsigned(inst->src[URB_LOGICAL_SRC_CHANNEL_MASK].file != BAD_FILE);
@@ -99,6 +100,15 @@ fs_visitor::validate()
          }
 
          fsv_assert_eq(header_size + data_size, inst->mlen);
+         break;
+      }
+
+      case SHADER_OPCODE_SEND:
+         fsv_assert(is_uniform(inst->src[0]) && is_uniform(inst->src[1]));
+         break;
+
+      default:
+         break;
       }
 
       if (inst->is_3src(compiler)) {

src/intel/compiler/brw_lower_logical_sends.cpp

@@ -370,6 +370,7 @@ lower_fb_write_logical_send(const fs_builder &bld, fs_inst *inst,
          desc = ubld.vgrf(BRW_REGISTER_TYPE_UD);
          ubld.AND(desc, dynamic_msaa_flags(prog_data),
                   brw_imm_ud(BRW_WM_MSAA_FLAG_COARSE_DISPATCH));
+         desc = component(desc, 0);
       }
 
       uint32_t ex_desc = 0;