Re: [Mesa-dev] [RFC 7/9] nir/nir: Use a linked list instead of a has set for use/def sets

2015-04-27 Thread Connor Abbott
On Mon, Apr 27, 2015 at 5:25 PM, Jason Ekstrand ja...@jlekstrand.net wrote:
 On Mon, Apr 27, 2015 at 1:35 PM, Connor Abbott cwabbo...@gmail.com wrote:
 On Fri, Apr 24, 2015 at 7:32 PM, Jason Ekstrand ja...@jlekstrand.net wrote:
 +struct nir_if;
 +
  typedef struct nir_src {
 union {
 +  nir_instr *parent_instr;
 +  struct nir_if *parent_if;
 +   };

 There's something I'm not quite understanding about this... how are we
 supposed to know which of parent_instr and parent_if are valid? If I
 walk over all the sources for a given SSA def or register, how am I
 supposed to know if it's part of an if-condition or an instruction? I
 would think that you would need a boolean here or have parent_instr
 and parent_if not be in a union.

 We do the same thing we did with the sets before.  We have separate
 uses and if_uses sets.  If it's in if_uses, you use the if.  If it's
 in uses, it's an instr.  We could put something in the source but that
 seems like it'll make for even more mess.
 --Jason

D'oh... right. That makes sense.

Connor
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Re: [Mesa-dev] [RFC 7/9] nir/nir: Use a linked list instead of a has set for use/def sets

2015-04-27 Thread Jason Ekstrand
On Mon, Apr 27, 2015 at 1:35 PM, Connor Abbott cwabbo...@gmail.com wrote:
 On Fri, Apr 24, 2015 at 7:32 PM, Jason Ekstrand ja...@jlekstrand.net wrote:
 +struct nir_if;
 +
  typedef struct nir_src {
 union {
 +  nir_instr *parent_instr;
 +  struct nir_if *parent_if;
 +   };

 There's something I'm not quite understanding about this... how are we
 supposed to know which of parent_instr and parent_if are valid? If I
 walk over all the sources for a given SSA def or register, how am I
 supposed to know if it's part of an if-condition or an instruction? I
 would think that you would need a boolean here or have parent_instr
 and parent_if not be in a union.

We do the same thing we did with the sets before.  We have separate
uses and if_uses sets.  If it's in if_uses, you use the if.  If it's
in uses, it's an instr.  We could put something in the source but that
seems like it'll make for even more mess.
--Jason
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Re: [Mesa-dev] [RFC 7/9] nir/nir: Use a linked list instead of a has set for use/def sets

2015-04-27 Thread Connor Abbott
On Fri, Apr 24, 2015 at 7:32 PM, Jason Ekstrand ja...@jlekstrand.net wrote:
 This commit switches us from the current setup of using hash sets for
 use/def sets to using linked lists.  Doing so should save us quite a bit of
 memory because we aren't carrying around 3 hash sets per register and 2 per
 SSA value.  It should also save us CPU time because adding/removing things
 from use/def sets is 4 pointer manipulations instead of a hash lookup.

 On the code complexity side of things, some things are now much easier and
 others are a bit harder.  One of the operations we perform constantly in
 optimization passes is to replace one source with another.  Due to the fact
 that an instruction can use the same SSA value multiple times, we had to
 iterate through the sources of the instruction and determine if the use we
 were replacing was the only one before removing it from the set of uses.
 With this patch, uses are per-source not per-instruction so we can just
 remove it safely.  On the other hand, trying to iterate over all of the
 instructions that use a given value is more difficult.  Fortunately, the
 two places we do that are the ffma peephole where it doesn't matter and GCM
 where we already gracefully handle duplicates visits to an instruction.

 Another aspect here is that using linked lists in this way can be tricky to
 get right.  With sets, things were quite forgiving and the worst that
 happened if you didn't properly remove a use was that it would get caught
 in the validator.  With linked lists, it can lead to linked list corruption
 which can be harder to track.  However, we do just as much validation of
 the linked lists as we did of the sets so the validator should still catch
 these problems.  While working on this series, the vast majority of the
 bugs I had to fix were caught by assertions.  I don't think the lists are
 going to be that much worse than the sets.
 ---
  src/glsl/nir/nir.c  | 232 
 
  src/glsl/nir/nir.h  |  27 --
  src/glsl/nir/nir_validate.c | 158 +++---
  3 files changed, 182 insertions(+), 235 deletions(-)

 diff --git a/src/glsl/nir/nir.c b/src/glsl/nir/nir.c
 index b8f5dd4..283b861 100644
 --- a/src/glsl/nir/nir.c
 +++ b/src/glsl/nir/nir.c
 @@ -58,12 +58,9 @@ reg_create(void *mem_ctx, struct exec_list *list)
 nir_register *reg = ralloc(mem_ctx, nir_register);

 reg-parent_instr = NULL;
 -   reg-uses = _mesa_set_create(reg, _mesa_hash_pointer,
 -_mesa_key_pointer_equal);
 -   reg-defs = _mesa_set_create(reg, _mesa_hash_pointer,
 -_mesa_key_pointer_equal);
 -   reg-if_uses = _mesa_set_create(reg, _mesa_hash_pointer,
 -   _mesa_key_pointer_equal);
 +   nir_list_init(reg-uses);
 +   nir_list_init(reg-defs);
 +   nir_list_init(reg-if_uses);

 reg-num_components = 0;
 reg-num_array_elems = 0;
 @@ -1070,11 +1067,14 @@ update_if_uses(nir_cf_node *node)

 nir_if *if_stmt = nir_cf_node_as_if(node);

 -   struct set *if_uses_set = if_stmt-condition.is_ssa ?
 - if_stmt-condition.ssa-if_uses :
 - if_stmt-condition.reg.reg-uses;
 -
 -   _mesa_set_add(if_uses_set, if_stmt);
 +   if_stmt-condition.parent_if = if_stmt;
 +   if (if_stmt-condition.is_ssa) {
 +  nir_list_push_tail(if_stmt-condition.ssa-if_uses,
 + if_stmt-condition.use_link);
 +   } else {
 +  nir_list_push_tail(if_stmt-condition.reg.reg-if_uses,
 + if_stmt-condition.use_link);
 +   }
  }

  void
 @@ -1227,16 +1227,7 @@ cleanup_cf_node(nir_cf_node *node)
foreach_list_typed(nir_cf_node, child, node, if_stmt-else_list)
   cleanup_cf_node(child);

 -  struct set *if_uses;
 -  if (if_stmt-condition.is_ssa) {
 - if_uses = if_stmt-condition.ssa-if_uses;
 -  } else {
 - if_uses = if_stmt-condition.reg.reg-if_uses;
 -  }
 -
 -  struct set_entry *entry = _mesa_set_search(if_uses, if_stmt);
 -  assert(entry);
 -  _mesa_set_remove(if_uses, entry);
 +  nir_link_remove(if_stmt-condition.use_link);
break;
 }

 @@ -1293,9 +1284,10 @@ add_use_cb(nir_src *src, void *state)
  {
 nir_instr *instr = state;

 -   struct set *uses_set = src-is_ssa ? src-ssa-uses : src-reg.reg-uses;
 -
 -   _mesa_set_add(uses_set, instr);
 +   src-parent_instr = instr;
 +   nir_link_init(src-use_link);
 +   nir_list *uses_list = src-is_ssa ? src-ssa-uses : src-reg.reg-uses;
 +   nir_list_push_tail(uses_list, src-use_link);

 return true;
  }
 @@ -1320,8 +1312,11 @@ add_reg_def_cb(nir_dest *dest, void *state)
  {
 nir_instr *instr = state;

 -   if (!dest-is_ssa)
 -  _mesa_set_add(dest-reg.reg-defs, instr);
 +   if (!dest-is_ssa) {
 +  dest-reg.parent_instr = instr;
 +  nir_link_init(dest-reg.def_link);
 +  nir_list_push_tail(dest-reg.reg-defs, 

Re: [Mesa-dev] [RFC 7/9] nir/nir: Use a linked list instead of a has set for use/def sets

2015-04-24 Thread Jason Ekstrand
On Fri, Apr 24, 2015 at 4:32 PM, Jason Ekstrand ja...@jlekstrand.net wrote:
 This commit switches us from the current setup of using hash sets for
 use/def sets to using linked lists.  Doing so should save us quite a bit of
 memory because we aren't carrying around 3 hash sets per register and 2 per
 SSA value.  It should also save us CPU time because adding/removing things
 from use/def sets is 4 pointer manipulations instead of a hash lookup.

I'm going to get some actual performance numbers for this but the
performance looks like we can save  about %10 on shader-db.  I should
have perf and memory numbers by some time on Monday.

 On the code complexity side of things, some things are now much easier and
 others are a bit harder.  One of the operations we perform constantly in
 optimization passes is to replace one source with another.  Due to the fact
 that an instruction can use the same SSA value multiple times, we had to
 iterate through the sources of the instruction and determine if the use we
 were replacing was the only one before removing it from the set of uses.
 With this patch, uses are per-source not per-instruction so we can just
 remove it safely.  On the other hand, trying to iterate over all of the
 instructions that use a given value is more difficult.  Fortunately, the
 two places we do that are the ffma peephole where it doesn't matter and GCM
 where we already gracefully handle duplicates visits to an instruction.

 Another aspect here is that using linked lists in this way can be tricky to
 get right.  With sets, things were quite forgiving and the worst that
 happened if you didn't properly remove a use was that it would get caught
 in the validator.  With linked lists, it can lead to linked list corruption
 which can be harder to track.  However, we do just as much validation of
 the linked lists as we did of the sets so the validator should still catch
 these problems.  While working on this series, the vast majority of the
 bugs I had to fix were caught by assertions.  I don't think the lists are
 going to be that much worse than the sets.
 ---
  src/glsl/nir/nir.c  | 232 
 
  src/glsl/nir/nir.h  |  27 --
  src/glsl/nir/nir_validate.c | 158 +++---
  3 files changed, 182 insertions(+), 235 deletions(-)

 diff --git a/src/glsl/nir/nir.c b/src/glsl/nir/nir.c
 index b8f5dd4..283b861 100644
 --- a/src/glsl/nir/nir.c
 +++ b/src/glsl/nir/nir.c
 @@ -58,12 +58,9 @@ reg_create(void *mem_ctx, struct exec_list *list)
 nir_register *reg = ralloc(mem_ctx, nir_register);

 reg-parent_instr = NULL;
 -   reg-uses = _mesa_set_create(reg, _mesa_hash_pointer,
 -_mesa_key_pointer_equal);
 -   reg-defs = _mesa_set_create(reg, _mesa_hash_pointer,
 -_mesa_key_pointer_equal);
 -   reg-if_uses = _mesa_set_create(reg, _mesa_hash_pointer,
 -   _mesa_key_pointer_equal);
 +   nir_list_init(reg-uses);
 +   nir_list_init(reg-defs);
 +   nir_list_init(reg-if_uses);

 reg-num_components = 0;
 reg-num_array_elems = 0;
 @@ -1070,11 +1067,14 @@ update_if_uses(nir_cf_node *node)

 nir_if *if_stmt = nir_cf_node_as_if(node);

 -   struct set *if_uses_set = if_stmt-condition.is_ssa ?
 - if_stmt-condition.ssa-if_uses :
 - if_stmt-condition.reg.reg-uses;
 -
 -   _mesa_set_add(if_uses_set, if_stmt);
 +   if_stmt-condition.parent_if = if_stmt;
 +   if (if_stmt-condition.is_ssa) {
 +  nir_list_push_tail(if_stmt-condition.ssa-if_uses,
 + if_stmt-condition.use_link);
 +   } else {
 +  nir_list_push_tail(if_stmt-condition.reg.reg-if_uses,
 + if_stmt-condition.use_link);
 +   }
  }

  void
 @@ -1227,16 +1227,7 @@ cleanup_cf_node(nir_cf_node *node)
foreach_list_typed(nir_cf_node, child, node, if_stmt-else_list)
   cleanup_cf_node(child);

 -  struct set *if_uses;
 -  if (if_stmt-condition.is_ssa) {
 - if_uses = if_stmt-condition.ssa-if_uses;
 -  } else {
 - if_uses = if_stmt-condition.reg.reg-if_uses;
 -  }
 -
 -  struct set_entry *entry = _mesa_set_search(if_uses, if_stmt);
 -  assert(entry);
 -  _mesa_set_remove(if_uses, entry);
 +  nir_link_remove(if_stmt-condition.use_link);
break;
 }

 @@ -1293,9 +1284,10 @@ add_use_cb(nir_src *src, void *state)
  {
 nir_instr *instr = state;

 -   struct set *uses_set = src-is_ssa ? src-ssa-uses : src-reg.reg-uses;
 -
 -   _mesa_set_add(uses_set, instr);
 +   src-parent_instr = instr;
 +   nir_link_init(src-use_link);
 +   nir_list *uses_list = src-is_ssa ? src-ssa-uses : src-reg.reg-uses;
 +   nir_list_push_tail(uses_list, src-use_link);

 return true;
  }
 @@ -1320,8 +1312,11 @@ add_reg_def_cb(nir_dest *dest, void *state)
  {
 nir_instr *instr = state;

 -   if (!dest-is_ssa)
 -  

[Mesa-dev] [RFC 7/9] nir/nir: Use a linked list instead of a has set for use/def sets

2015-04-24 Thread Jason Ekstrand
This commit switches us from the current setup of using hash sets for
use/def sets to using linked lists.  Doing so should save us quite a bit of
memory because we aren't carrying around 3 hash sets per register and 2 per
SSA value.  It should also save us CPU time because adding/removing things
from use/def sets is 4 pointer manipulations instead of a hash lookup.

On the code complexity side of things, some things are now much easier and
others are a bit harder.  One of the operations we perform constantly in
optimization passes is to replace one source with another.  Due to the fact
that an instruction can use the same SSA value multiple times, we had to
iterate through the sources of the instruction and determine if the use we
were replacing was the only one before removing it from the set of uses.
With this patch, uses are per-source not per-instruction so we can just
remove it safely.  On the other hand, trying to iterate over all of the
instructions that use a given value is more difficult.  Fortunately, the
two places we do that are the ffma peephole where it doesn't matter and GCM
where we already gracefully handle duplicates visits to an instruction.

Another aspect here is that using linked lists in this way can be tricky to
get right.  With sets, things were quite forgiving and the worst that
happened if you didn't properly remove a use was that it would get caught
in the validator.  With linked lists, it can lead to linked list corruption
which can be harder to track.  However, we do just as much validation of
the linked lists as we did of the sets so the validator should still catch
these problems.  While working on this series, the vast majority of the
bugs I had to fix were caught by assertions.  I don't think the lists are
going to be that much worse than the sets.
---
 src/glsl/nir/nir.c  | 232 
 src/glsl/nir/nir.h  |  27 --
 src/glsl/nir/nir_validate.c | 158 +++---
 3 files changed, 182 insertions(+), 235 deletions(-)

diff --git a/src/glsl/nir/nir.c b/src/glsl/nir/nir.c
index b8f5dd4..283b861 100644
--- a/src/glsl/nir/nir.c
+++ b/src/glsl/nir/nir.c
@@ -58,12 +58,9 @@ reg_create(void *mem_ctx, struct exec_list *list)
nir_register *reg = ralloc(mem_ctx, nir_register);
 
reg-parent_instr = NULL;
-   reg-uses = _mesa_set_create(reg, _mesa_hash_pointer,
-_mesa_key_pointer_equal);
-   reg-defs = _mesa_set_create(reg, _mesa_hash_pointer,
-_mesa_key_pointer_equal);
-   reg-if_uses = _mesa_set_create(reg, _mesa_hash_pointer,
-   _mesa_key_pointer_equal);
+   nir_list_init(reg-uses);
+   nir_list_init(reg-defs);
+   nir_list_init(reg-if_uses);
 
reg-num_components = 0;
reg-num_array_elems = 0;
@@ -1070,11 +1067,14 @@ update_if_uses(nir_cf_node *node)
 
nir_if *if_stmt = nir_cf_node_as_if(node);
 
-   struct set *if_uses_set = if_stmt-condition.is_ssa ?
- if_stmt-condition.ssa-if_uses :
- if_stmt-condition.reg.reg-uses;
-
-   _mesa_set_add(if_uses_set, if_stmt);
+   if_stmt-condition.parent_if = if_stmt;
+   if (if_stmt-condition.is_ssa) {
+  nir_list_push_tail(if_stmt-condition.ssa-if_uses,
+ if_stmt-condition.use_link);
+   } else {
+  nir_list_push_tail(if_stmt-condition.reg.reg-if_uses,
+ if_stmt-condition.use_link);
+   }
 }
 
 void
@@ -1227,16 +1227,7 @@ cleanup_cf_node(nir_cf_node *node)
   foreach_list_typed(nir_cf_node, child, node, if_stmt-else_list)
  cleanup_cf_node(child);
 
-  struct set *if_uses;
-  if (if_stmt-condition.is_ssa) {
- if_uses = if_stmt-condition.ssa-if_uses;
-  } else {
- if_uses = if_stmt-condition.reg.reg-if_uses;
-  }
-
-  struct set_entry *entry = _mesa_set_search(if_uses, if_stmt);
-  assert(entry);
-  _mesa_set_remove(if_uses, entry);
+  nir_link_remove(if_stmt-condition.use_link);
   break;
}
 
@@ -1293,9 +1284,10 @@ add_use_cb(nir_src *src, void *state)
 {
nir_instr *instr = state;
 
-   struct set *uses_set = src-is_ssa ? src-ssa-uses : src-reg.reg-uses;
-
-   _mesa_set_add(uses_set, instr);
+   src-parent_instr = instr;
+   nir_link_init(src-use_link);
+   nir_list *uses_list = src-is_ssa ? src-ssa-uses : src-reg.reg-uses;
+   nir_list_push_tail(uses_list, src-use_link);
 
return true;
 }
@@ -1320,8 +1312,11 @@ add_reg_def_cb(nir_dest *dest, void *state)
 {
nir_instr *instr = state;
 
-   if (!dest-is_ssa)
-  _mesa_set_add(dest-reg.reg-defs, instr);
+   if (!dest-is_ssa) {
+  dest-reg.parent_instr = instr;
+  nir_link_init(dest-reg.def_link);
+  nir_list_push_tail(dest-reg.reg-defs, dest-reg.def_link);
+   }
 
return true;
 }
@@ -1436,13 +1431,7 @@ nir_instr_insert_after_cf_list(struct exec_list *list, 
nir_instr *after)
 static bool