From a961d6c0146e3ee4bb8a4baa50ca475b56239bc5 Mon Sep 17 00:00:00 2001
From: bmeurer <bmeurer@chromium.org>
Date: Wed, 3 Jun 2015 04:23:06 -0700
Subject: [PATCH] [x64] Smi zero can be used as an immediate.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1150853009

Cr-Commit-Position: refs/heads/master@{#28786}
---
 src/compiler/x64/code-generator-x64.cc       | 7 ++++++-
 src/compiler/x64/instruction-selector-x64.cc | 4 ++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/compiler/x64/code-generator-x64.cc b/src/compiler/x64/code-generator-x64.cc
index 2105d66e4..b4d200b39 100644
--- a/src/compiler/x64/code-generator-x64.cc
+++ b/src/compiler/x64/code-generator-x64.cc
@@ -38,7 +38,12 @@ class X64OperandConverter : public InstructionOperandConverter {
   Operand OutputOperand() { return ToOperand(instr_->Output()); }
 
   Immediate ToImmediate(InstructionOperand* operand) {
-    return Immediate(ToConstant(operand).ToInt32());
+    Constant constant = ToConstant(operand);
+    if (constant.type() == Constant::kFloat64) {
+      DCHECK_EQ(0, bit_cast<int64_t>(constant.ToFloat64()));
+      return Immediate(0);
+    }
+    return Immediate(constant.ToInt32());
   }
 
   Operand ToOperand(InstructionOperand* op, int extra = 0) {
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index df0f8809a..c841acebc 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -27,6 +27,10 @@ class X64OperandGenerator final : public OperandGenerator {
         const int64_t value = OpParameter<int64_t>(node);
         return value == static_cast<int64_t>(static_cast<int32_t>(value));
       }
+      case IrOpcode::kNumberConstant: {
+        const double value = OpParameter<double>(node);
+        return bit_cast<int64_t>(value) == 0;
+      }
       default:
         return false;
     }
-- 
2.34.1