i965/fs: Add an instruction flag for choosing the flag subregister.

We're going to redo discard handling to track discards in the other flag
subregister, saving instructions in the discard and allowing predicated
jumps out to the end of the shader.

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

diff --git a/src/mesa/drivers/dri/i965/brw_eu.c b/src/mesa/drivers/dri/i965/brw_eu.c
index 46ada8d995cc743ade7b9f04bc1605656a0bd3e1..360089cf13170179ea23ce8e6d6aa6f7f859a1f7 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_eu.c
+++ b/src/mesa/drivers/dri/i965/brw_eu.c
@@ -94,6 +94,12 @@ void brw_set_conditionalmod( struct brw_compile *p, GLuint conditional )
    p->current->header.destreg__conditionalmod = conditional;
 }
 
+void brw_set_flag_reg(struct brw_compile *p, int reg, int subreg)
+{
+   p->current->bits2.da1.flag_reg_nr = reg;
+   p->current->bits2.da1.flag_subreg_nr = subreg;
+}
+
 void brw_set_access_mode( struct brw_compile *p, GLuint access_mode )
 {
    p->current->header.access_mode = access_mode;

diff --git a/src/mesa/drivers/dri/i965/brw_eu.h b/src/mesa/drivers/dri/i965/brw_eu.h
index e43b543dd96cde5fc8e298d0df80a4b32be3c1c1..adefcfd9badd39190f1ffe4742b2aa3a3f4f2d6e 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_eu.h
+++ b/src/mesa/drivers/dri/i965/brw_eu.h
@@ -810,6 +810,7 @@ void brw_set_predicate_control_flag_value( struct brw_compile *p, GLuint value )
 void brw_set_predicate_control( struct brw_compile *p, GLuint pc );
 void brw_set_predicate_inverse(struct brw_compile *p, bool predicate_inverse);
 void brw_set_conditionalmod( struct brw_compile *p, GLuint conditional );
+void brw_set_flag_reg(struct brw_compile *p, int reg, int subreg);
 void brw_set_acc_write_control(struct brw_compile *p, GLuint value);
 
 void brw_init_compile(struct brw_context *, struct brw_compile *p,

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index d77a67e0240acc5d8fd73fcbde5e36e2fc0082b2..dbf48f89d7e2500290e256bfb781949b78184eb6 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2222,6 +2222,12 @@ fs_visitor::remove_duplicate_mrf_writes()
 void
 fs_visitor::dump_instruction(fs_inst *inst)
 {
+   if (inst->predicate) {
+      printf("(%cf0.%d) ",
+             inst->predicate_inverse ? '-' : '+',
+             inst->flag_subreg);
+   }
+
    if (inst->opcode < ARRAY_SIZE(opcode_descs) &&
        opcode_descs[inst->opcode].name) {
       printf("%s", opcode_descs[inst->opcode].name);
@@ -2230,8 +2236,18 @@ fs_visitor::dump_instruction(fs_inst *inst)
    }
    if (inst->saturate)
       printf(".sat");
+   if (inst->conditional_mod) {
+      printf(".cmod");
+      if (!inst->predicate &&
+          (intel->gen < 5 || (inst->opcode != BRW_OPCODE_SEL &&
+                              inst->opcode != BRW_OPCODE_IF &&
+                              inst->opcode != BRW_OPCODE_WHILE))) {
+         printf(".f0.%d\n", inst->flag_subreg);
+      }
+   }
    printf(" ");
 
+
    switch (inst->dst.file) {
    case GRF:
       printf("vgrf%d", inst->dst.reg);

diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 51efc113fcc10cd6d663b2e60e3a49a0f41ece20..b60a37e459264db4267e77b3697f81bfb4d5a093 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -165,6 +165,11 @@ public:
    bool saturate;
    int conditional_mod; /**< BRW_CONDITIONAL_* */
 
+   /* Chooses which flag subregister (f0.0 or f0.1) is used for conditional
+    * mod and predication.
+    */
+   uint8_t flag_subreg;
+
    int mlen; /**< SEND message length */
    int base_mrf; /**< First MRF in the SEND message, if mlen is nonzero. */
    uint32_t texture_offset; /**< Texture offset bitfield */
@@ -511,7 +516,7 @@ private:
                                                  struct brw_reg dst,
                                                  struct brw_reg index,
                                                  struct brw_reg offset);
-   void generate_mov_dispatch_to_flags();
+   void generate_mov_dispatch_to_flags(fs_inst *inst);
 
    struct brw_context *brw;
    struct intel_context *intel;

diff --git a/src/mesa/drivers/dri/i965/brw_fs_emit.cpp b/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
index 0750b86793cd9bd1c8828af77fe2c64450b2bd76..b3d7f81f1a49be7cb477c55ddcd77ae6c1d778fa 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
@@ -742,15 +742,15 @@ fs_generator::generate_varying_pull_constant_load_gen7(fs_inst *inst,
  * Used only on Gen6 and above.
  */
 void
-fs_generator::generate_mov_dispatch_to_flags()
+fs_generator::generate_mov_dispatch_to_flags(fs_inst *inst)
 {
-   struct brw_reg f0 = brw_flag_reg(0, 0);
+   struct brw_reg flags = brw_flag_reg(0, inst->flag_subreg);
    struct brw_reg g1 = retype(brw_vec1_grf(1, 7), BRW_REGISTER_TYPE_UW);
 
    assert (intel->gen >= 6);
    brw_push_insn_state(p);
    brw_set_mask_control(p, BRW_MASK_DISABLE);
-   brw_MOV(p, f0, g1);
+   brw_MOV(p, flags, g1);
    brw_pop_insn_state(p);
 }
 
@@ -915,6 +915,7 @@ fs_generator::generate_code(exec_list *instructions)
       brw_set_conditionalmod(p, inst->conditional_mod);
       brw_set_predicate_control(p, inst->predicate);
       brw_set_predicate_inverse(p, inst->predicate_inverse);
+      brw_set_flag_reg(p, 0, inst->flag_subreg);
       brw_set_saturate(p, inst->saturate);
       brw_set_mask_control(p, inst->force_writemask_all);
 
@@ -1121,7 +1122,7 @@ fs_generator::generate_code(exec_list *instructions)
         break;
 
       case FS_OPCODE_MOV_DISPATCH_TO_FLAGS:
-         generate_mov_dispatch_to_flags();
+         generate_mov_dispatch_to_flags(inst);
          break;
 
       case SHADER_OPCODE_SHADER_TIME_ADD:

diff --git a/src/mesa/drivers/dri/i965/brw_fs_schedule_instructions.cpp b/src/mesa/drivers/dri/i965/brw_fs_schedule_instructions.cpp
index 6b7c412f8e740e73616b6485eed61ed4ae688760..96d1131f10c0e7e55c25fdc42aa4d6a79c595d3d 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs_schedule_instructions.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_schedule_instructions.cpp
@@ -249,7 +249,7 @@ instruction_scheduler::calculate_deps()
 {
    schedule_node *last_grf_write[virtual_grf_count];
    schedule_node *last_mrf_write[BRW_MAX_MRF];
-   schedule_node *last_conditional_mod = NULL;
+   schedule_node *last_conditional_mod[2] = { NULL, NULL };
    /* Fixed HW registers are assumed to be separate from the virtual
     * GRFs, so they can be tracked separately.  We don't really write
     * to fixed GRFs much, so don't bother tracking them on a more
@@ -299,8 +299,8 @@ instruction_scheduler::calculate_deps()
       }
 
       if (inst->predicate) {
-        assert(last_conditional_mod);
-        add_dep(last_conditional_mod, n);
+        assert(last_conditional_mod[inst->flag_subreg]);
+        add_dep(last_conditional_mod[inst->flag_subreg], n);
       }
 
       /* write-after-write deps. */
@@ -339,15 +339,15 @@ instruction_scheduler::calculate_deps()
        */
       if (inst->conditional_mod ||
           inst->opcode == FS_OPCODE_MOV_DISPATCH_TO_FLAGS) {
-        add_dep(last_conditional_mod, n, 0);
-        last_conditional_mod = n;
+        add_dep(last_conditional_mod[inst->flag_subreg], n, 0);
+        last_conditional_mod[inst->flag_subreg] = n;
       }
    }
 
    /* bottom-to-top dependencies: WAR */
    memset(last_grf_write, 0, sizeof(last_grf_write));
    memset(last_mrf_write, 0, sizeof(last_mrf_write));
-   last_conditional_mod = NULL;
+   memset(last_conditional_mod, 0, sizeof(last_conditional_mod));
    last_fixed_grf_write = NULL;
 
    exec_node *node;
@@ -383,7 +383,7 @@ instruction_scheduler::calculate_deps()
       }
 
       if (inst->predicate) {
-        add_dep(n, last_conditional_mod);
+        add_dep(n, last_conditional_mod[inst->flag_subreg]);
       }
 
       /* Update the things this instruction wrote, so earlier reads
@@ -422,7 +422,7 @@ instruction_scheduler::calculate_deps()
        */
       if (inst->conditional_mod ||
           inst->opcode == FS_OPCODE_MOV_DISPATCH_TO_FLAGS) {
-        last_conditional_mod = n;
+        last_conditional_mod[inst->flag_subreg] = n;
       }
    }
 }