From 480729ff79c3c20f65d4d38c61080eb70e7d3505 Mon Sep 17 00:00:00 2001
From: "verwaest@chromium.org"
 <verwaest@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Mon, 29 Jul 2013 17:07:28 +0000
Subject: [PATCH] Smi-support for HSar.

BUG=
R=mvstanton@chromium.org

Review URL: https://chromiumcodereview.appspot.com/21049003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15938 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/arm/lithium-arm.cc           | 7 +++++--
 src/arm/lithium-codegen-arm.cc   | 3 +++
 src/hydrogen-instructions.h      | 4 +++-
 src/ia32/lithium-codegen-ia32.cc | 3 +++
 src/ia32/lithium-ia32.cc         | 7 +++++--
 src/x64/lithium-x64.cc           | 3 ++-
 6 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index b55679e..f728619 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -733,7 +733,9 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
     constant_value = constant->Integer32Value() & 0x1f;
     // Left shifts can deoptimize if we shift by > 0 and the result cannot be
     // truncated to smi.
-    if (instr->representation().IsSmi() && constant_value > 0) {
+    if (instr->representation().IsSmi() &&
+        op == Token::SHL &&
+        constant_value > 0) {
       for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
         if (!it.value()->CheckFlag(HValue::kTruncatingToSmi)) {
           does_deopt = true;
@@ -752,7 +754,8 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
       does_deopt = !instr->CheckFlag(HInstruction::kUint32);
     } else {
       for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
-        if (!it.value()->CheckFlag(HValue::kTruncatingToInt32)) {
+        if (!it.value()->CheckFlag(HValue::kTruncatingToInt32) &&
+            !it.value()->CheckFlag(HValue::kTruncatingToSmi)) {
           does_deopt = true;
           break;
         }
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 929d04d..8cdc886 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -1725,6 +1725,9 @@ void LCodeGen::DoShiftI(LShiftI* instr) {
       case Token::SAR:
         if (shift_count != 0) {
           __ mov(result, Operand(left, ASR, shift_count));
+          if (instr->hydrogen_value()->representation().IsSmi()) {
+            __ and_(result, result, Operand(~kSmiTagMask));
+          }
         } else {
           __ Move(result, left);
         }
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index e71b7cd..077d47b 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -4964,7 +4964,9 @@ class HShr: public HBitwiseBinaryOperation {
   virtual void UpdateRepresentation(Representation new_rep,
                                     HInferRepresentationPhase* h_infer,
                                     const char* reason) {
-    if (new_rep.IsSmi()) new_rep = Representation::Integer32();
+    if (new_rep.IsSmi() && !right()->IsConstant()) {
+      new_rep = Representation::Integer32();
+    }
     HBitwiseBinaryOperation::UpdateRepresentation(new_rep, h_infer, reason);
   }
 
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 3ddad06..5096ea8 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -1757,6 +1757,9 @@ void LCodeGen::DoShiftI(LShiftI* instr) {
       case Token::SAR:
         if (shift_count != 0) {
           __ sar(ToRegister(left), shift_count);
+          if (instr->hydrogen_value()->representation().IsSmi()) {
+            __ and_(ToRegister(left), ~kSmiTagMask);
+          }
         }
         break;
       case Token::SHR:
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 8c8103f..026c2a4 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -787,7 +787,9 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
     constant_value = constant->Integer32Value() & 0x1f;
     // Left shifts can deoptimize if we shift by > 0 and the result cannot be
     // truncated to smi.
-    if (instr->representation().IsSmi() && constant_value > 0) {
+    if (instr->representation().IsSmi() &&
+        op == Token::SHL &&
+        constant_value > 0) {
       for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
         if (!it.value()->CheckFlag(HValue::kTruncatingToSmi)) {
           does_deopt = true;
@@ -806,7 +808,8 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
       does_deopt = !instr->CheckFlag(HInstruction::kUint32);
     } else {
       for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
-        if (!it.value()->CheckFlag(HValue::kTruncatingToInt32)) {
+        if (!it.value()->CheckFlag(HValue::kTruncatingToInt32) &&
+            !it.value()->CheckFlag(HValue::kTruncatingToSmi)) {
           does_deopt = true;
           break;
         }
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index 4153417..79b575d 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -751,7 +751,8 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
       does_deopt = !instr->CheckFlag(HInstruction::kUint32);
     } else {
       for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
-        if (!it.value()->CheckFlag(HValue::kTruncatingToInt32)) {
+        if (!it.value()->CheckFlag(HValue::kTruncatingToInt32) &&
+            !it.value()->CheckFlag(HValue::kTruncatingToSmi)) {
           does_deopt = true;
           break;
         }
-- 
2.7.4