intel/compiler: Move all live interval analysis results into fs_live_variables

This moves the following methods that are currently defined in
fs_visitor (even though they are side products of the liveness
analysis computation) and are already implemented in
brw_fs_live_variables.cpp:

> bool virtual_grf_interferes(int a, int b) const;
> int *virtual_grf_start;
> int *virtual_grf_end;

It makes sense for them to be part of the fs_live_variables object,
because they have the same lifetime as other liveness analysis results
and because this will allow some extra validation to happen wherever
they are accessed in order to make sure that we only ever use
up-to-date liveness analysis results.

This shortens the virtual_grf prefix in order to compensate for the
slightly increased lexical overhead from the live_intervals pointer
dereference.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>

diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
index e12650c..2afe599 100644 (file)
--- a/src/intel/compiler/brw_fs.cpp
+++ b/src/intel/compiler/brw_fs.cpp
@@ -2037,7 +2037,7 @@ fs_visitor::split_virtual_grfs()
 }
 
 /**
- * Remove unused virtual GRFs and compact the virtual_grf_* arrays.
+ * Remove unused virtual GRFs and compact the vgrf_* arrays.
  *
  * During code generation, we create tons of temporary variables, many of
  * which get immediately killed and are never used again.  Yet, in later
@@ -3117,7 +3117,7 @@ fs_visitor::compute_to_mrf()
       /* Can't compute-to-MRF this GRF if someone else was going to
        * read it later.
        */
-      if (this->virtual_grf_end[inst->src[0].nr] > ip)
+      if (live_intervals->vgrf_end[inst->src[0].nr] > ip)
         continue;
 
       /* Found a move of a GRF to a MRF.  Let's see if we can go rewrite the
@@ -7372,7 +7372,8 @@ fs_visitor::calculate_register_pressure()
    regs_live_at_ip = rzalloc_array(mem_ctx, int, num_instructions);
 
    for (unsigned reg = 0; reg < alloc.count; reg++) {
-      for (int ip = virtual_grf_start[reg]; ip <= virtual_grf_end[reg]; ip++)
+      for (int ip = live_intervals->vgrf_start[reg];
+           ip <= live_intervals->vgrf_end[reg]; ip++)
          regs_live_at_ip[ip] += alloc.sizes[reg];
    }
 }

diff --git a/src/intel/compiler/brw_fs.h b/src/intel/compiler/brw_fs.h
index 46bf679..17b8713 100644 (file)
--- a/src/intel/compiler/brw_fs.h
+++ b/src/intel/compiler/brw_fs.h
@@ -151,7 +151,6 @@ public:
    bool remove_extra_rounding_modes();
 
    bool opt_sampler_eot();
-   bool virtual_grf_interferes(int a, int b) const;
    void schedule_instructions(instruction_scheduler_mode mode);
    void insert_gen4_send_dependency_workarounds();
    void insert_gen4_pre_send_dependency_workarounds(bblock_t *block,
@@ -320,8 +319,8 @@ public:
 
    const struct brw_vue_map *input_vue_map;
 
-   int *virtual_grf_start;
-   int *virtual_grf_end;
+   int *param_size;
+
    brw::fs_live_variables *live_intervals;
 
    int *regs_live_at_ip;

diff --git a/src/intel/compiler/brw_fs_copy_propagation.cpp b/src/intel/compiler/brw_fs_copy_propagation.cpp
index 262fc2c..8e04dde 100644 (file)
--- a/src/intel/compiler/brw_fs_copy_propagation.cpp
+++ b/src/intel/compiler/brw_fs_copy_propagation.cpp
@@ -1035,8 +1035,8 @@ fs_visitor::opt_copy_propagation()
       for (unsigned a = 0; a < ACP_HASH_SIZE; a++) {
          foreach_in_list_safe(acp_entry, entry, &out_acp[block->num][a]) {
             assert(entry->dst.file == VGRF);
-            if (block->start_ip <= virtual_grf_start[entry->dst.nr] &&
-                virtual_grf_end[entry->dst.nr] <= block->end_ip)
+            if (block->start_ip <= live_intervals->vgrf_start[entry->dst.nr] &&
+                live_intervals->vgrf_end[entry->dst.nr] <= block->end_ip)
                entry->remove();
          }
       }

diff --git a/src/intel/compiler/brw_fs_cse.cpp b/src/intel/compiler/brw_fs_cse.cpp
index ffc6f03..d80b70a 100644 (file)
--- a/src/intel/compiler/brw_fs_cse.cpp
+++ b/src/intel/compiler/brw_fs_cse.cpp
@@ -360,7 +360,8 @@ fs_visitor::opt_cse_local(bblock_t *block, int &ip)
             /* Kill any AEB entries using registers that don't get reused any
              * more -- a sure sign they'll fail operands_match().
              */
-            if (src_reg->file == VGRF && virtual_grf_end[src_reg->nr] < ip) {
+            if (src_reg->file == VGRF &&
+                live_intervals->vgrf_end[src_reg->nr] < ip) {
                entry->remove();
                ralloc_free(entry);
                break;

diff --git a/src/intel/compiler/brw_fs_live_variables.cpp b/src/intel/compiler/brw_fs_live_variables.cpp
index 5c4f3a1..1befc5a 100644 (file)
--- a/src/intel/compiler/brw_fs_live_variables.cpp
+++ b/src/intel/compiler/brw_fs_live_variables.cpp
@@ -282,6 +282,13 @@ fs_live_variables::fs_live_variables(fs_visitor *v, const cfg_t *cfg)
       end[i] = -1;
    }
 
+   vgrf_start = ralloc_array(mem_ctx, int, num_vgrfs);
+   vgrf_end = ralloc_array(mem_ctx, int, num_vgrfs);
+   for (int i = 0; i < num_vgrfs; i++) {
+      vgrf_start[i] = MAX_INSTRUCTION;
+      vgrf_end[i] = -1;
+   }
+
    block_data = rzalloc_array(mem_ctx, struct block_data, cfg->num_blocks);
 
    bitset_words = BITSET_WORDS(num_vars);
@@ -302,6 +309,13 @@ fs_live_variables::fs_live_variables(fs_visitor *v, const cfg_t *cfg)
    setup_def_use();
    compute_live_variables();
    compute_start_end();
+
+   /* Merge the per-component live ranges to whole VGRF live ranges. */
+   for (int i = 0; i < num_vars; i++) {
+      const unsigned vgrf = vgrf_from_var[i];
+      vgrf_start[vgrf] = MIN2(vgrf_start[vgrf], start[i]);
+      vgrf_end[vgrf] = MAX2(vgrf_end[vgrf], end[i]);
+   }
 }
 
 fs_live_variables::~fs_live_variables()
@@ -328,27 +342,7 @@ fs_visitor::calculate_live_intervals()
    if (this->live_intervals)
       return;
 
-   int num_vgrfs = this->alloc.count;
-   ralloc_free(this->virtual_grf_start);
-   ralloc_free(this->virtual_grf_end);
-   virtual_grf_start = ralloc_array(mem_ctx, int, num_vgrfs);
-   virtual_grf_end = ralloc_array(mem_ctx, int, num_vgrfs);
-
-   for (int i = 0; i < num_vgrfs; i++) {
-      virtual_grf_start[i] = MAX_INSTRUCTION;
-      virtual_grf_end[i] = -1;
-   }
-
    this->live_intervals = new(mem_ctx) fs_live_variables(this, cfg);
-
-   /* Merge the per-component live ranges to whole VGRF live ranges. */
-   for (int i = 0; i < live_intervals->num_vars; i++) {
-      int vgrf = live_intervals->vgrf_from_var[i];
-      virtual_grf_start[vgrf] = MIN2(virtual_grf_start[vgrf],
-                                     live_intervals->start[i]);
-      virtual_grf_end[vgrf] = MAX2(virtual_grf_end[vgrf],
-                                   live_intervals->end[i]);
-   }
 }
 
 bool
@@ -359,8 +353,8 @@ fs_live_variables::vars_interfere(int a, int b) const
 }
 
 bool
-fs_visitor::virtual_grf_interferes(int a, int b) const
+fs_live_variables::vgrfs_interfere(int a, int b) const
 {
-   return !(virtual_grf_end[a] <= virtual_grf_start[b] ||
-            virtual_grf_end[b] <= virtual_grf_start[a]);
+   return !(vgrf_end[a] <= vgrf_start[b] ||
+            vgrf_end[b] <= vgrf_start[a]);
 }

diff --git a/src/intel/compiler/brw_fs_live_variables.h b/src/intel/compiler/brw_fs_live_variables.h
index 65220f5..655245c 100644 (file)
--- a/src/intel/compiler/brw_fs_live_variables.h
+++ b/src/intel/compiler/brw_fs_live_variables.h
@@ -82,6 +82,7 @@ public:
    ~fs_live_variables();
 
    bool vars_interfere(int a, int b) const;
+   bool vgrfs_interfere(int a, int b) const;
    int var_from_reg(const fs_reg &reg) const
    {
       return var_from_vgrf[reg.nr] + reg.offset / REG_SIZE;
@@ -110,6 +111,13 @@ public:
    int *end;
    /** @} */
 
+   /** @{
+    * Final computed live ranges for each VGRF.
+    */
+   int *vgrf_start;
+   int *vgrf_end;
+   /** @} */
+
    /** Per-basic-block information on live variables */
    struct block_data *block_data;
 

diff --git a/src/intel/compiler/brw_fs_reg_allocate.cpp b/src/intel/compiler/brw_fs_reg_allocate.cpp
index f8ef23e..9e6e414 100644 (file)
--- a/src/intel/compiler/brw_fs_reg_allocate.cpp
+++ b/src/intel/compiler/brw_fs_reg_allocate.cpp
@@ -567,7 +567,7 @@ fs_reg_alloc::setup_live_interference(unsigned node,
       if (payload_last_use_ip[i] == -1)
          continue;
 
-      /* Note that we use a <= comparison, unlike virtual_grf_interferes(),
+      /* Note that we use a <= comparison, unlike vgrfs_interfere(),
        * in order to not have to worry about the uniform issue described in
        * calculate_live_intervals().
        */
@@ -590,8 +590,8 @@ fs_reg_alloc::setup_live_interference(unsigned node,
    for (unsigned n2 = first_vgrf_node;
         n2 < (unsigned)first_spill_node && n2 < node; n2++) {
       unsigned vgrf = n2 - first_vgrf_node;
-      if (!(node_end_ip <= fs->virtual_grf_start[vgrf] ||
-            fs->virtual_grf_end[vgrf] <= node_start_ip))
+      if (!(node_end_ip <= fs->live_intervals->vgrf_start[vgrf] ||
+            fs->live_intervals->vgrf_end[vgrf] <= node_start_ip))
          ra_add_node_interference(g, node, n2);
    }
 }
@@ -812,8 +812,8 @@ fs_reg_alloc::build_interference_graph(bool allow_spilling)
    /* Add interference based on the live range of the register */
    for (unsigned i = 0; i < fs->alloc.count; i++) {
       setup_live_interference(first_vgrf_node + i,
-                              fs->virtual_grf_start[i],
-                              fs->virtual_grf_end[i]);
+                              fs->live_intervals->vgrf_start[i],
+                              fs->live_intervals->vgrf_end[i]);
    }
 
    /* Add interference based on the instructions in which a register is used.
@@ -953,7 +953,7 @@ fs_reg_alloc::set_spill_costs()
       if (no_spill[i])
          continue;
 
-      int live_length = fs->virtual_grf_end[i] - fs->virtual_grf_start[i];
+      int live_length = fs->live_intervals->vgrf_end[i] - fs->live_intervals->vgrf_start[i];
       if (live_length <= 0)
          continue;
 

diff --git a/src/intel/compiler/brw_fs_visitor.cpp b/src/intel/compiler/brw_fs_visitor.cpp
index f7baeb5..92332eb 100644 (file)
--- a/src/intel/compiler/brw_fs_visitor.cpp
+++ b/src/intel/compiler/brw_fs_visitor.cpp
@@ -933,8 +933,6 @@ fs_visitor::init()
    this->first_non_payload_grf = 0;
    this->max_grf = devinfo->gen >= 7 ? GEN7_MRF_HACK_START : BRW_MAX_GRF;
 
-   this->virtual_grf_start = NULL;
-   this->virtual_grf_end = NULL;
    this->live_intervals = NULL;
    this->regs_live_at_ip = NULL;
 

diff --git a/src/intel/compiler/brw_schedule_instructions.cpp b/src/intel/compiler/brw_schedule_instructions.cpp
index 64a43c1..596b99e 100644 (file)
--- a/src/intel/compiler/brw_schedule_instructions.cpp
+++ b/src/intel/compiler/brw_schedule_instructions.cpp
@@ -754,8 +754,8 @@ fs_instruction_scheduler::setup_liveness(cfg_t *cfg)
     */
    for (int block = 0; block < cfg->num_blocks - 1; block++) {
       for (int i = 0; i < grf_count; i++) {
-         if (v->virtual_grf_start[i] <= cfg->blocks[block]->end_ip &&
-             v->virtual_grf_end[i] >= cfg->blocks[block + 1]->start_ip) {
+         if (v->live_intervals->vgrf_start[i] <= cfg->blocks[block]->end_ip &&
+             v->live_intervals->vgrf_end[i] >= cfg->blocks[block + 1]->start_ip) {
             if (!BITSET_TEST(livein[block + 1], i)) {
                 reg_pressure_in[block + 1] += v->alloc.sizes[i];
                 BITSET_SET(livein[block + 1], i);