intel/fs: Use helper for discard sample mask flag subregister number.

Use it instead of hard-coding f0.1 for the sample mask of programs
that use discard.  This will make the task easier when we replace f0.1
with another flag register location in order to support discard with
SIMD32 shaders.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
index ee40287..b583454 100644 (file)
--- a/src/intel/compiler/brw_fs.cpp
+++ b/src/intel/compiler/brw_fs.cpp
@@ -1532,7 +1532,7 @@ fs_visitor::emit_discard_jump()
     * shader if all relevant channels have been discarded.
     */
    fs_inst *discard_jump = bld.emit(FS_OPCODE_DISCARD_JUMP);
-   discard_jump->flag_subreg = 1;
+   discard_jump->flag_subreg = sample_mask_flag_subreg(this);
 
    discard_jump->predicate = BRW_PREDICATE_ALIGN1_ANY4H;
    discard_jump->predicate_inverse = true;
@@ -4286,7 +4286,7 @@ sample_mask_reg(const fs_builder &bld)
       return brw_imm_ud(0xffffffff);
    } else if (brw_wm_prog_data(v->stage_prog_data)->uses_kill) {
       assert(bld.group() < 16 && bld.dispatch_width() <= 16);
-      return brw_flag_reg(0, 1);
+      return brw_flag_subreg(sample_mask_flag_subreg(v));
    } else {
       assert(v->devinfo->gen >= 6 && bld.dispatch_width() <= 16);
       return retype(brw_vec1_grf((bld.group() >= 16 ? 2 : 1), 7),

diff --git a/src/intel/compiler/brw_fs.h b/src/intel/compiler/brw_fs.h
index dfa1ff4..93d3e46 100644 (file)
--- a/src/intel/compiler/brw_fs.h
+++ b/src/intel/compiler/brw_fs.h
@@ -418,6 +418,17 @@ private:
 };
 
 /**
+ * Return the flag register used in fragment shaders to keep track of live
+ * samples.
+ */
+static inline unsigned
+sample_mask_flag_subreg(const fs_visitor *shader)
+{
+   assert(shader->stage == MESA_SHADER_FRAGMENT);
+   return 1;
+}
+
+/**
  * The fragment shader code generator.
  *
  * Translates FS IR to actual i965 assembly code.

diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp
index fab27c1..93c6ee2 100644 (file)
--- a/src/intel/compiler/brw_fs_nir.cpp
+++ b/src/intel/compiler/brw_fs_nir.cpp
@@ -3435,7 +3435,7 @@ fs_visitor::nir_emit_fs_intrinsic(const fs_builder &bld,
       fs_inst *mov = bld.MOV(dest, brw_imm_ud(~0));
       mov->predicate = BRW_PREDICATE_NORMAL;
       mov->predicate_inverse = true;
-      mov->flag_subreg = 1;
+      mov->flag_subreg = sample_mask_flag_subreg(this);
       break;
    }
 
@@ -3552,7 +3552,7 @@ fs_visitor::nir_emit_fs_intrinsic(const fs_builder &bld,
       }
 
       cmp->predicate = BRW_PREDICATE_NORMAL;
-      cmp->flag_subreg = 1;
+      cmp->flag_subreg = sample_mask_flag_subreg(this);
 
       if (devinfo->gen >= 6) {
          /* Due to the way we implement discard, the jump will only happen

diff --git a/src/intel/compiler/brw_fs_visitor.cpp b/src/intel/compiler/brw_fs_visitor.cpp
index 5cb2400..f7baeb5 100644 (file)
--- a/src/intel/compiler/brw_fs_visitor.cpp
+++ b/src/intel/compiler/brw_fs_visitor.cpp
@@ -455,7 +455,7 @@ fs_visitor::emit_single_fb_write(const fs_builder &bld,
 
    if (prog_data->uses_kill) {
       write->predicate = BRW_PREDICATE_NORMAL;
-      write->flag_subreg = 1;
+      write->flag_subreg = sample_mask_flag_subreg(this);
    }
 
    return write;