From 74ce265aad8b1f993b712c69f3a07ad714536cd8 Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Wed, 16 Jul 2014 10:53:38 -0700
Subject: [PATCH] Bug 845068 - IonMonkey: GVN: Implement congruentTo and
 valueHash for more load nodes, exposing more congruences and reducing
 collisions r=nbp

---
 js/src/jit/MIR.cpp | 68 ++++++++++++++++++++++++++++++++++++++++++----
 js/src/jit/MIR.h   | 10 +++++++
 2 files changed, 73 insertions(+), 5 deletions(-)

diff --git a/js/src/jit/MIR.cpp b/js/src/jit/MIR.cpp
index ead13b1a4459..3b63592bae92 100644
--- a/js/src/jit/MIR.cpp
+++ b/js/src/jit/MIR.cpp
@@ -174,14 +174,18 @@ MDefinition::printName(FILE *fp) const
     fprintf(fp, "%u", id());
 }
 
+HashNumber
+MDefinition::addU32ToHash(HashNumber hash, uint32_t data)
+{
+    return data + (hash << 6) + (hash << 16) - hash;
+}
+
 HashNumber
 MDefinition::valueHash() const
 {
     HashNumber out = op();
-    for (size_t i = 0, e = numOperands(); i < e; i++) {
-        uint32_t valueNumber = getOperand(i)->id();
-        out = valueNumber + (out << 6) + (out << 16) - out;
-    }
+    for (size_t i = 0, e = numOperands(); i < e; i++)
+        out = addU32ToHash(out, getOperand(i)->id());
     return out;
 }
 
@@ -686,7 +690,9 @@ MParameter::printOpcode(FILE *fp) const
 HashNumber
 MParameter::valueHash() const
 {
-    return index_; // Why not?
+    HashNumber hash = MDefinition::valueHash();
+    hash = addU32ToHash(hash, index_);
+    return hash;
 }
 
 bool
@@ -2866,6 +2872,14 @@ MAsmJSLoadGlobalVar::mightAlias(const MDefinition *def) const
     return true;
 }
 
+HashNumber
+MAsmJSLoadGlobalVar::valueHash() const
+{
+    HashNumber hash = MDefinition::valueHash();
+    hash = addU32ToHash(hash, globalDataOffset_);
+    return hash;
+}
+
 bool
 MAsmJSLoadGlobalVar::congruentTo(const MDefinition *ins) const
 {
@@ -2876,6 +2890,42 @@ MAsmJSLoadGlobalVar::congruentTo(const MDefinition *ins) const
     return false;
 }
 
+HashNumber
+MAsmJSLoadFuncPtr::valueHash() const
+{
+    HashNumber hash = MDefinition::valueHash();
+    hash = addU32ToHash(hash, globalDataOffset_);
+    return hash;
+}
+
+bool
+MAsmJSLoadFuncPtr::congruentTo(const MDefinition *ins) const
+{
+    if (ins->isAsmJSLoadFuncPtr()) {
+        const MAsmJSLoadFuncPtr *load = ins->toAsmJSLoadFuncPtr();
+        return globalDataOffset_ == load->globalDataOffset_;
+    }
+    return false;
+}
+
+HashNumber
+MAsmJSLoadFFIFunc::valueHash() const
+{
+    HashNumber hash = MDefinition::valueHash();
+    hash = addU32ToHash(hash, globalDataOffset_);
+    return hash;
+}
+
+bool
+MAsmJSLoadFFIFunc::congruentTo(const MDefinition *ins) const
+{
+    if (ins->isAsmJSLoadFFIFunc()) {
+        const MAsmJSLoadFFIFunc *load = ins->toAsmJSLoadFFIFunc();
+        return globalDataOffset_ == load->globalDataOffset_;
+    }
+    return false;
+}
+
 bool
 MLoadSlot::mightAlias(const MDefinition *store) const
 {
@@ -2884,6 +2934,14 @@ MLoadSlot::mightAlias(const MDefinition *store) const
     return true;
 }
 
+HashNumber
+MLoadSlot::valueHash() const
+{
+    HashNumber hash = MDefinition::valueHash();
+    hash = addU32ToHash(hash, slot_);
+    return hash;
+}
+
 bool
 MGuardShapePolymorphic::congruentTo(const MDefinition *ins) const
 {
diff --git a/js/src/jit/MIR.h b/js/src/jit/MIR.h
index 18871e12015b..273857f13912 100644
--- a/js/src/jit/MIR.h
+++ b/js/src/jit/MIR.h
@@ -360,6 +360,8 @@ class MDefinition : public MNode
         block_ = block;
     }
 
+    static HashNumber addU32ToHash(HashNumber hash, uint32_t data);
+
   public:
     MDefinition()
       : id_(0),
@@ -8111,6 +8113,7 @@ class MLoadSlot
         return slot_;
     }
 
+    HashNumber valueHash() const;
     bool congruentTo(const MDefinition *ins) const {
         if (!ins->isLoadSlot())
             return false;
@@ -10402,6 +10405,7 @@ class MAsmJSLoadGlobalVar : public MNullaryInstruction
 
     unsigned globalDataOffset() const { return globalDataOffset_; }
 
+    HashNumber valueHash() const;
     bool congruentTo(const MDefinition *ins) const;
 
     AliasSet getAliasSet() const {
@@ -10455,6 +10459,9 @@ class MAsmJSLoadFuncPtr : public MUnaryInstruction
 
     unsigned globalDataOffset() const { return globalDataOffset_; }
     MDefinition *index() const { return getOperand(0); }
+
+    HashNumber valueHash() const;
+    bool congruentTo(const MDefinition *ins) const;
 };
 
 class MAsmJSLoadFFIFunc : public MNullaryInstruction
@@ -10476,6 +10483,9 @@ class MAsmJSLoadFFIFunc : public MNullaryInstruction
     }
 
     unsigned globalDataOffset() const { return globalDataOffset_; }
+
+    HashNumber valueHash() const;
+    bool congruentTo(const MDefinition *ins) const;
 };
 
 class MAsmJSParameter : public MNullaryInstruction