intel/ir: Allow arbitrary scratch flag registers for SHADER_OPCODE_FIND_LIVE_CHANNEL.

This shouldn't cause any functional change at this point, it changes
SHADER_OPCODE_FIND_LIVE_CHANNEL to use the flag register specified at
the IR level instead of the hard-coded f1.0, now that it can be
represented in backend_instruction::flag_subreg.  This will be
necessary for scheduling to behave correctly once more things start
making use of f1.0.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/intel/compiler/brw_eu_emit.c b/src/intel/compiler/brw_eu_emit.c
index a96fe43..14b1c59 100644 (file)
--- a/src/intel/compiler/brw_eu_emit.c
+++ b/src/intel/compiler/brw_eu_emit.c
@@ -3399,7 +3399,9 @@ brw_find_live_channel(struct brw_codegen *p, struct brw_reg dst,
           */
          inst = brw_FBL(p, vec1(dst), exec_mask);
       } else {
-         const struct brw_reg flag = brw_flag_reg(1, 0);
+         const struct brw_reg flag = brw_flag_reg(
+            brw_inst_flag_reg_nr(devinfo, p->current),
+            brw_inst_flag_subreg_nr(devinfo, p->current));
 
          brw_set_default_exec_size(p, BRW_EXECUTE_1);
          brw_MOV(p, retype(flag, BRW_REGISTER_TYPE_UD), brw_imm_ud(0));
@@ -3418,7 +3420,6 @@ brw_find_live_channel(struct brw_codegen *p, struct brw_reg dst,
             brw_inst_set_mask_control(devinfo, inst, BRW_MASK_ENABLE);
             brw_inst_set_group(devinfo, inst, lower_size * i + 8 * qtr_control);
             brw_inst_set_cond_modifier(devinfo, inst, BRW_CONDITIONAL_Z);
-            brw_inst_set_flag_reg_nr(devinfo, inst, 1);
             brw_inst_set_exec_size(devinfo, inst, cvt(lower_size) - 1);
          }
 

diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
index 16b6a06..c255a3b 100644 (file)
--- a/src/intel/compiler/brw_fs.cpp
+++ b/src/intel/compiler/brw_fs.cpp
@@ -931,7 +931,8 @@ fs_inst::flags_written() const
    if ((conditional_mod && (opcode != BRW_OPCODE_SEL &&
                             opcode != BRW_OPCODE_IF &&
                             opcode != BRW_OPCODE_WHILE)) ||
-       opcode == FS_OPCODE_MOV_DISPATCH_TO_FLAGS) {
+       opcode == FS_OPCODE_MOV_DISPATCH_TO_FLAGS ||
+       opcode == SHADER_OPCODE_FIND_LIVE_CHANNEL) {
       return flag_mask(this);
    } else {
       return flag_mask(dst, size_written);

diff --git a/src/intel/compiler/brw_fs_builder.h b/src/intel/compiler/brw_fs_builder.h
index 874272b..b157e33 100644 (file)
--- a/src/intel/compiler/brw_fs_builder.h
+++ b/src/intel/compiler/brw_fs_builder.h
@@ -406,7 +406,7 @@ namespace brw {
          const dst_reg chan_index = vgrf(BRW_REGISTER_TYPE_UD);
          const dst_reg dst = vgrf(src.type);
 
-         ubld.emit(SHADER_OPCODE_FIND_LIVE_CHANNEL, chan_index);
+         ubld.emit(SHADER_OPCODE_FIND_LIVE_CHANNEL, chan_index)->flag_subreg = 2;
          ubld.emit(SHADER_OPCODE_BROADCAST, dst, src, component(chan_index, 0));
 
          return src_reg(component(dst, 0));