RealNeGate · March 4, 2024 04:58 · Mar 4, 2024 · Mar 4, 2024 · Mar 4, 2024 · Mar 4, 2024
diff --git a/combined_solver.c b/combined_solver.c
@@ -1,5 +1,6 @@
-// combined "Peeps + ConstProp + GVN" solver (Combining Analyses, Combining Optimizations 7.3.2)
-// returns isomorphic node.
+// combined "Peeps + ConstProp + GVN" solver (extended version of the one in Combining Analyses, Combining Optimizations 7.3.2)
+//
+// returns isomorphic node (might be the same node).
 Node* peephole_node(Optimizer* opt, Node* n) {
   Node* k;
   bool progress = false;

diff --git a/combined_solver.c b/combined_solver.c
@@ -1,4 +1,4 @@
-// combined "Peeps + ConstProp + GVN" solver.
+// combined "Peeps + ConstProp + GVN" solver (Combining Analyses, Combining Optimizations 7.3.2)
 // returns isomorphic node.
 Node* peephole_node(Optimizer* opt, Node* n) {
   Node* k;

diff --git a/combined_solver.c b/combined_solver.c
@@ -9,7 +9,7 @@ Node* peephole_node(Optimizer* opt, Node* n) {
 
   // iterative convergence (rewrite peepholes):
   //   we'll settle on a fixpoint and be happy.
-  while (k = ideal(), k) { n = k; }
+  while (k = ideal(n), k) { n = k; }
 
   // tries to deduce the value of an op based on the
   // types of the inputs, if both inputs were deduced

diff --git a/combined_solver.c b/combined_solver.c
@@ -1,5 +1,5 @@
 // combined "Peeps + ConstProp + GVN" solver.
-// returns NULL if it made no progress
+// returns isomorphic node.
 Node* peephole_node(Optimizer* opt, Node* n) {
   Node* k;
   bool progress = false;
@@ -9,16 +9,7 @@ Node* peephole_node(Optimizer* opt, Node* n) {
 
   // iterative convergence (rewrite peepholes):
   //   we'll settle on a fixpoint and be happy.
-  while (k = ideal(), k) {
-    // we can recycle the node which means we'll make progress (k != NULL),
-    // but don't need to move the node uses.
-    if (n != k) {
-      subsume_node(opt, n, k);
-      worklist_push_users(ws, k);
-      n = k;
-    }
-    progress = true;
-  }
+  while (k = ideal(), k) { n = k; }
 
   // tries to deduce the value of an op based on the
   // types of the inputs, if both inputs were deduced
@@ -48,16 +39,5 @@ Node* peephole_node(Optimizer* opt, Node* n) {
     return k;
   }
 
-  return progress ? n : NULL;
-}
-
-void peephole(Optimizer* opt, Worklist* ws) {
-  Node* n;
-  while (n = worklist_pop(ws), n) {
-    Node* k = peephole_node(ws, n);
-    if (k) {  
-      if (n != k) { subsume_node(opt, n, k); }
-      worklist_push_users(ws, k);
-    }
-  }
+  return n;
 }
diff --git a/combined_solver.c b/combined_solver.c
@@ -55,7 +55,7 @@ void peephole(Optimizer* opt, Worklist* ws) {
   Node* n;
   while (n = worklist_pop(ws), n) {
     Node* k = peephole_node(ws, n);
-    if (k != NULL) {  
+    if (k) {  
       if (n != k) { subsume_node(opt, n, k); }
       worklist_push_users(ws, k);
     }

diff --git a/combined_solver.c b/combined_solver.c
@@ -56,7 +56,7 @@ void peephole(Optimizer* opt, Worklist* ws) {
   while (n = worklist_pop(ws), n) {
     Node* k = peephole_node(ws, n);
     if (k != NULL) {  
-      subsume_node(opt, n, k);
+      if (n != k) { subsume_node(opt, n, k); }
       worklist_push_users(ws, k);
     }
   }

diff --git a/combined_solver.c b/combined_solver.c
@@ -1,7 +1,7 @@
 // combined "Peeps + ConstProp + GVN" solver.
 // returns NULL if it made no progress
 Node* peephole_node(Optimizer* opt, Node* n) {
-  Node* k = n;
+  Node* k;
   bool progress = false;
 
   // potential mutations from ideal() means we need to get rehash.

diff --git a/combined_solver.c b/combined_solver.c
@@ -2,6 +2,7 @@
 // returns NULL if it made no progress
 Node* peephole_node(Optimizer* opt, Node* n) {
   Node* k = n;
+  bool progress = false;
 
   // potential mutations from ideal() means we need to get rehash.
   hashset_remove(opt->gvn_nodes, n);
@@ -16,6 +17,7 @@ Node* peephole_node(Optimizer* opt, Node* n) {
       worklist_push_users(ws, k);
       n = k;
     }
+    progress = true;
   }
 
   // tries to deduce the value of an op based on the
@@ -46,9 +48,7 @@ Node* peephole_node(Optimizer* opt, Node* n) {
     return k;
   }
 
-  // either k is NULL and it's already in it's normal form or
-  // it's not and we performed some idealize ops.
-  return k;
+  return progress ? n : NULL;
 }
 
 void peephole(Optimizer* opt, Worklist* ws) {

diff --git a/combined_solver.c b/combined_solver.c
@@ -1,7 +1,10 @@
 // combined "Peeps + ConstProp + GVN" solver.
 // returns NULL if it made no progress
 Node* peephole_node(Optimizer* opt, Node* n) {
-  Node* k;
+  Node* k = n;
+
+  // potential mutations from ideal() means we need to get rehash.
+  hashset_remove(opt->gvn_nodes, n);
 
   // iterative convergence (rewrite peepholes):
   //   we'll settle on a fixpoint and be happy.
@@ -43,8 +46,9 @@ Node* peephole_node(Optimizer* opt, Node* n) {
     return k;
   }
 
-  // it's already in it's normal form (no progress)
-  return NULL;
+  // either k is NULL and it's already in it's normal form or
+  // it's not and we performed some idealize ops.
+  return k;
 }
 
 void peephole(Optimizer* opt, Worklist* ws) {

diff --git a/combined_solver.c b/combined_solver.c
@@ -26,7 +26,8 @@ Node* peephole_node(Optimizer* opt, Node* n) {
   // this is ops which replace the node with a direct
   // input (x + 0 => x), because of this we don't need
   // to rerun const prop since they don't change nodes
-  // just referenced existing ones.
+  // just referenced existing ones (which are either in
+  // normal form or waiting on the worklist).
   //
   // identity(opt, n) will always return a node, either n
   // or a direct replacement

diff --git a/combined_solver.c b/combined_solver.c
@@ -1,11 +1,23 @@
-// combined SimpleConstProp + Identity + GVN solver.
+// combined "Peeps + ConstProp + GVN" solver.
 // returns NULL if it made no progress
 Node* peephole_node(Optimizer* opt, Node* n) {
   Node* k;
+
+  // iterative convergence (rewrite peepholes):
+  //   we'll settle on a fixpoint and be happy.
+  while (k = ideal(), k) {
+    // we can recycle the node which means we'll make progress (k != NULL),
+    // but don't need to move the node uses.
+    if (n != k) {
+      subsume_node(opt, n, k);
+      worklist_push_users(ws, k);
+      n = k;
+    }
+  }
 
   // tries to deduce the value of an op based on the
   // types of the inputs, if both inputs were deduced
-  // constant we'd be constants and if both inputs were
+  // constant we might be constant and if both inputs were
   // ranges we might infer extra data if not a constant.
   Type* t = value(opt, n);
   k = try_as_const(opt, n, t);

diff --git a/combined_solver.c b/combined_solver.c
@@ -34,10 +34,13 @@ Node* peephole_node(Optimizer* opt, Node* n) {
   return NULL;
 }
 
-void peephole(Worklist* ws) {
+void peephole(Optimizer* opt, Worklist* ws) {
   Node* n;
   while (n = worklist_pop(ws), n) {
     Node* k = peephole_node(ws, n);
-    if (k != NULL) { worklist_push_users(ws, k); }
+    if (k != NULL) {  
+      subsume_node(opt, n, k);
+      worklist_push_users(ws, k);
+    }
   }
 }
diff --git a/combined_solver.c b/combined_solver.c
@@ -0,0 +1,43 @@
+// combined SimpleConstProp + Identity + GVN solver.
+// returns NULL if it made no progress
+Node* peephole_node(Optimizer* opt, Node* n) {
+  Node* k;
+
+  // tries to deduce the value of an op based on the
+  // types of the inputs, if both inputs were deduced
+  // constant we'd be constants and if both inputs were
+  // ranges we might infer extra data if not a constant.
+  Type* t = value(opt, n);
+  k = try_as_const(opt, n, t);
+  if (k) { return k; }
+
+  // this is ops which replace the node with a direct
+  // input (x + 0 => x), because of this we don't need
+  // to rerun const prop since they don't change nodes
+  // just referenced existing ones.
+  //
+  // identity(opt, n) will always return a node, either n
+  // or a direct replacement
+  k = identity(opt, n);
+  if (k != n) { return k; }
+
+  // GVN, we literally just place nodes into a hash table.
+  // no need to rerun it's ruleset if it's just referencing
+  // an existing node.
+  k = hashset_get(opt->gvn_nodes, n);
+  if (k) {
+    hashset_put(opt->gvn_nodes, k);
+    return k;
+  }
+
+  // it's already in it's normal form (no progress)
+  return NULL;
+}
+
+void peephole(Worklist* ws) {
+  Node* n;
+  while (n = worklist_pop(ws), n) {
+    Node* k = peephole_node(ws, n);
+    if (k != NULL) { worklist_push_users(ws, k); }
+  }
+}
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