commit a66784b09f10d847b49bc878f10c45690e212f0b
author Shalini Salomi Bodapati <shalini.salomi.bodapati@intel.com> Tue Nov 06 13:05:44 2018 +0530
committer Shalini Salomi Bodapati <shalini.salomi.bodapati@intel.com> Mon Nov 12 21:09:32 2018 +0530
tree a18ee4ec39a44256223b9f756159bfd535ddfde3
parent fe59955fc41e277bf1c60378202ba785abb1e4a8

Optimize mod power 2 for x86

Test: 411-checker-hdiv-hrem-pow2, test.py --host

Change-Id: I9334a3eb2cb50df439b56c0161379fef46e58603
Signed-off-by: Shalini Salomi Bodapati <shalini.salomi.bodapati@intel.com>

compiler/optimizing/code_generator_x86_64.cc

diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index dac2dba..b9ae2cd 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -3560,7 +3560,40 @@
       LOG(FATAL) << "Unexpected type for div by (-)1 " << instruction->GetResultType();
   }
 }
+void InstructionCodeGeneratorX86_64::RemByPowerOfTwo(HRem* instruction) {
+  LocationSummary* locations = instruction->GetLocations();
+  Location second = locations->InAt(1);
+  CpuRegister out = locations->Out().AsRegister<CpuRegister>();
+  CpuRegister numerator = locations->InAt(0).AsRegister<CpuRegister>();
+  int64_t imm = Int64FromConstant(second.GetConstant());
+  DCHECK(IsPowerOfTwo(AbsOrMin(imm)));
+  uint64_t abs_imm = AbsOrMin(imm);
+  CpuRegister tmp = locations->GetTemp(0).AsRegister<CpuRegister>();
+  if (instruction->GetResultType() == DataType::Type::kInt32) {
+    NearLabel done;
+    __ movl(out, numerator);
+    __ andl(out, Immediate(abs_imm-1));
+    __ j(Condition::kZero, &done);
+    __ leal(tmp, Address(out, static_cast<int32_t>(~(abs_imm-1))));
+    __ testl(numerator, numerator);
+    __ cmov(Condition::kLess, out, tmp, false);
+    __ Bind(&done);
 
+  } else {
+    DCHECK_EQ(instruction->GetResultType(), DataType::Type::kInt64);
+    codegen_->Load64BitValue(tmp, abs_imm - 1);
+    NearLabel done;
+
+    __ movq(out, numerator);
+    __ andq(out, tmp);
+    __ j(Condition::kZero, &done);
+    __ movq(tmp, numerator);
+    __ sarq(tmp, Immediate(63));
+    __ shlq(tmp, Immediate(WhichPowerOf2(abs_imm)));
+    __ orq(out, tmp);
+    __ Bind(&done);
+  }
+}
 void InstructionCodeGeneratorX86_64::DivByPowerOfTwo(HDiv* instruction) {
   LocationSummary* locations = instruction->GetLocations();
   Location second = locations->InAt(1);
@@ -3737,8 +3770,12 @@
       // Do not generate anything. DivZeroCheck would prevent any code to be executed.
     } else if (imm == 1 || imm == -1) {
       DivRemOneOrMinusOne(instruction);
-    } else if (instruction->IsDiv() && IsPowerOfTwo(AbsOrMin(imm))) {
-      DivByPowerOfTwo(instruction->AsDiv());
+    } else if (IsPowerOfTwo(AbsOrMin(imm))) {
+      if (is_div) {
+        DivByPowerOfTwo(instruction->AsDiv());
+      } else {
+        RemByPowerOfTwo(instruction->AsRem());
+      }
     } else {
       DCHECK(imm <= -2 || imm >= 2);
       GenerateDivRemWithAnyConstant(instruction);