commit 5f7b58ea1adfc0639dd605b65f59198d3763f801
author Vladimir Marko <vmarko@google.com> Mon Nov 23 19:49:34 2015 +0000
committer Vladimir Marko <vmarko@google.com> Wed Dec 23 09:59:07 2015 +0000
tree 04556e673cdd3967cc967ff79931eab49e523956
parent 1201804d1813d7db0accead9721d67c40b3de564

Rewrite HInstruction::Is/As<type>().

Make Is<type>() and As<type>() non-virtual for concrete
instruction types, relying on GetKind(), and mark GetKind()
as PURE to improve optimization opportunities. This reduces
the number of relocations in libart-compiler.so's .rel.dyn
section by ~4K, or ~44%, and in .data.rel.ro by ~18K, or
~65%. The file is 96KiB smaller for Nexus 5, including 8KiB
reduction of the .text section.

Unfortunately, the g++/clang++ __attribute__((pure)) is not
strong enough to avoid duplicated virtual calls and we would
need the C++ [[pure]] attribute proposed in n3744 instead.
To work around this deficiency, we introduce an extra
non-virtual indirection for GetKind(), so that the compiler
can optimize common expressions such as
    instruction->IsAdd() || instruction->IsSub()
or
    instruction->IsAdd() && instruction->AsAdd()->...
which contain two virtual calls to GetKind() after inlining.

Change-Id: I83787de0671a5cb9f5b0a5f4a536cef239d5b401

compiler/optimizing/code_generator_x86.cc

diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 7a5b8db..3136109 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -1554,7 +1554,7 @@
 
     Location lhs = condition->GetLocations()->InAt(0);
     Location rhs = condition->GetLocations()->InAt(1);
-    // LHS is guaranteed to be in a register (see LocationsBuilderX86::VisitCondition).
+    // LHS is guaranteed to be in a register (see LocationsBuilderX86::HandleCondition).
     if (rhs.IsRegister()) {
       __ cmpl(lhs.AsRegister<Register>(), rhs.AsRegister<Register>());
     } else if (rhs.IsConstant()) {
@@ -1659,7 +1659,7 @@
 void InstructionCodeGeneratorX86::VisitStoreLocal(HStoreLocal* store ATTRIBUTE_UNUSED) {
 }
 
-void LocationsBuilderX86::VisitCondition(HCondition* cond) {
+void LocationsBuilderX86::HandleCondition(HCondition* cond) {
   LocationSummary* locations =
       new (GetGraph()->GetArena()) LocationSummary(cond, LocationSummary::kNoCall);
   // Handle the long/FP comparisons made in instruction simplification.
@@ -1692,7 +1692,7 @@
   }
 }
 
-void InstructionCodeGeneratorX86::VisitCondition(HCondition* cond) {
+void InstructionCodeGeneratorX86::HandleCondition(HCondition* cond) {
   if (!cond->NeedsMaterialization()) {
     return;
   }
@@ -1753,83 +1753,83 @@
 }
 
 void LocationsBuilderX86::VisitEqual(HEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitEqual(HEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitNotEqual(HNotEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitNotEqual(HNotEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitLessThan(HLessThan* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitLessThan(HLessThan* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitLessThanOrEqual(HLessThanOrEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitLessThanOrEqual(HLessThanOrEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitGreaterThan(HGreaterThan* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitGreaterThan(HGreaterThan* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitGreaterThanOrEqual(HGreaterThanOrEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitGreaterThanOrEqual(HGreaterThanOrEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitBelow(HBelow* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitBelow(HBelow* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitBelowOrEqual(HBelowOrEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitBelowOrEqual(HBelowOrEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitAbove(HAbove* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitAbove(HAbove* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitAboveOrEqual(HAboveOrEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void InstructionCodeGeneratorX86::VisitAboveOrEqual(HAboveOrEqual* comp) {
-  VisitCondition(comp);
+  HandleCondition(comp);
 }
 
 void LocationsBuilderX86::VisitIntConstant(HIntConstant* constant) {