[optimizing] x86: Prefer add over lea if possible

Looking at some generated code, I noticed an lea being used when an add
was sufficient.  Check for that case, and generate the add.

Fixed for x86 and x86_64.

Change-Id: I110304ff0fed8837ada96d34353a293d29022ce5
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>

diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index a6f01da..597d27e 100644 (file)
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -1959,6 +1959,8 @@ void InstructionCodeGeneratorX86::VisitAdd(HAdd* add) {
       if (second.IsRegister()) {
         if (out.AsRegister<Register>() == first.AsRegister<Register>()) {
           __ addl(out.AsRegister<Register>(), second.AsRegister<Register>());
+        } else if (out.AsRegister<Register>() == second.AsRegister<Register>()) {
+          __ addl(out.AsRegister<Register>(), first.AsRegister<Register>());
         } else {
           __ leal(out.AsRegister<Register>(), Address(
               first.AsRegister<Register>(), second.AsRegister<Register>(), TIMES_1, 0));

diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index f49c26d..68e0065 100644 (file)
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -2117,6 +2117,8 @@ void InstructionCodeGeneratorX86_64::VisitAdd(HAdd* add) {
       if (second.IsRegister()) {
         if (out.AsRegister<Register>() == first.AsRegister<Register>()) {
           __ addl(out.AsRegister<CpuRegister>(), second.AsRegister<CpuRegister>());
+        } else if (out.AsRegister<Register>() == second.AsRegister<Register>()) {
+          __ addl(out.AsRegister<CpuRegister>(), first.AsRegister<CpuRegister>());
         } else {
           __ leal(out.AsRegister<CpuRegister>(), Address(
               first.AsRegister<CpuRegister>(), second.AsRegister<CpuRegister>(), TIMES_1, 0));
@@ -2140,6 +2142,8 @@ void InstructionCodeGeneratorX86_64::VisitAdd(HAdd* add) {
       if (second.IsRegister()) {
         if (out.AsRegister<Register>() == first.AsRegister<Register>()) {
           __ addq(out.AsRegister<CpuRegister>(), second.AsRegister<CpuRegister>());
+        } else if (out.AsRegister<Register>() == second.AsRegister<Register>()) {
+          __ addq(out.AsRegister<CpuRegister>(), first.AsRegister<CpuRegister>());
         } else {
           __ leaq(out.AsRegister<CpuRegister>(), Address(
               first.AsRegister<CpuRegister>(), second.AsRegister<CpuRegister>(), TIMES_1, 0));