X87: [turbofan]: Micro optimizations to lea[l/q] on ia32/x64.

  port 87ae05c7 (r40341)

  original commit message:
  Utilize all opportunities to turn leas into adds.

BUG=

Review-Url: https://codereview.chromium.org/2429763002
Cr-Commit-Position: refs/heads/master@{#40386}

src/compiler/x87/code-generator-x87.cc

@@ -1870,7 +1870,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
           if (i.InputRegister(1).is(i.OutputRegister())) {
             __ shl(i.OutputRegister(), 1);
           } else {
-            __ lea(i.OutputRegister(), i.MemoryOperand());
+            __ add(i.OutputRegister(), i.InputRegister(1));
           }
         } else if (mode == kMode_M2) {
           __ shl(i.OutputRegister(), 1);
@@ -1881,6 +1881,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         } else {
           __ lea(i.OutputRegister(), i.MemoryOperand());
         }
+      } else if (mode == kMode_MR1 &&
+                 i.InputRegister(1).is(i.OutputRegister())) {
+        __ add(i.OutputRegister(), i.InputRegister(0));
       } else {
         __ lea(i.OutputRegister(), i.MemoryOperand());
       }