[turbofan] ARM: Use SBFX in instruction selector.

Support SBFX in the instruction selector for sign-extension patterns like
Sar(Shl(x, a), b), where a and b are immediate values.

BUG=

Review URL: https://codereview.chromium.org/1695293002

Cr-Commit-Position: refs/heads/master@{#34029}

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

@@ -672,6 +672,13 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       DCHECK_EQ(LeaveCC, i.OutputSBit());
       break;
     }
+    case kArmSbfx: {
+      CpuFeatureScope scope(masm(), ARMv7);
+      __ sbfx(i.OutputRegister(), i.InputRegister(0), i.InputInt8(1),
+              i.InputInt8(2));
+      DCHECK_EQ(LeaveCC, i.OutputSBit());
+      break;
+    }
     case kArmSxtb:
       __ sxtb(i.OutputRegister(), i.InputRegister(0), i.InputInt32(1));
       DCHECK_EQ(LeaveCC, i.OutputSBit());

src/compiler/arm/instruction-codes-arm.h

@@ -36,6 +36,7 @@ namespace compiler {
   V(ArmMvn)                        \
   V(ArmBfc)                        \
   V(ArmUbfx)                       \
+  V(ArmSbfx)                       \
   V(ArmSxtb)                       \
   V(ArmSxth)                       \
   V(ArmSxtab)                      \

src/compiler/arm/instruction-scheduler-arm.cc

@@ -38,6 +38,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArmMvn:
     case kArmBfc:
     case kArmUbfx:
+    case kArmSbfx:
     case kArmSxtb:
     case kArmSxth:
     case kArmSxtab:

src/compiler/arm/instruction-selector-arm.cc

@@ -733,14 +733,23 @@ void InstructionSelector::VisitWord32Sar(Node* node) {
   Int32BinopMatcher m(node);
   if (CanCover(m.node(), m.left().node()) && m.left().IsWord32Shl()) {
     Int32BinopMatcher mleft(m.left().node());
-    if (mleft.right().Is(16) && m.right().Is(16)) {
-      Emit(kArmSxth, g.DefineAsRegister(node),
-           g.UseRegister(mleft.left().node()), g.TempImmediate(0));
-      return;
-    } else if (mleft.right().Is(24) && m.right().Is(24)) {
-      Emit(kArmSxtb, g.DefineAsRegister(node),
-           g.UseRegister(mleft.left().node()), g.TempImmediate(0));
-      return;
+    if (m.right().HasValue() && mleft.right().HasValue()) {
+      uint32_t sar = m.right().Value();
+      uint32_t shl = mleft.right().Value();
+      if ((sar == shl) && (sar == 16)) {
+        Emit(kArmSxth, g.DefineAsRegister(node),
+             g.UseRegister(mleft.left().node()), g.TempImmediate(0));
+        return;
+      } else if ((sar == shl) && (sar == 24)) {
+        Emit(kArmSxtb, g.DefineAsRegister(node),
+             g.UseRegister(mleft.left().node()), g.TempImmediate(0));
+        return;
+      } else if (IsSupported(ARMv7) && (sar >= shl)) {
+        Emit(kArmSbfx, g.DefineAsRegister(node),
+             g.UseRegister(mleft.left().node()), g.TempImmediate(sar - shl),
+             g.TempImmediate(32 - sar));
+        return;
+      }
     }
   }
   VisitShift(this, node, TryMatchASR);

test/unittests/compiler/arm/instruction-selector-arm-unittest.cc

@@ -2544,6 +2544,25 @@ TEST_F(InstructionSelectorTest, Uint32ModWithParametersForSUDIVAndMLS) {
 }
 
 
+TEST_F(InstructionSelectorTest, Word32ShlWord32SarForSbfx) {
+  TRACED_FORRANGE(int32_t, shl, 1, 31) {
+    TRACED_FORRANGE(int32_t, sar, shl, 31) {
+      if ((shl == sar) && (sar == 16)) continue;  // Sxth.
+      if ((shl == sar) && (sar == 24)) continue;  // Sxtb.
+      StreamBuilder m(this, MachineType::Int32(), MachineType::Int32());
+      m.Return(m.Word32Sar(m.Word32Shl(m.Parameter(0), m.Int32Constant(shl)),
+                           m.Int32Constant(sar)));
+      Stream s = m.Build(ARMv7);
+      ASSERT_EQ(1U, s.size());
+      EXPECT_EQ(kArmSbfx, s[0]->arch_opcode());
+      ASSERT_EQ(3U, s[0]->InputCount());
+      EXPECT_EQ(sar - shl, s.ToInt32(s[0]->InputAt(1)));
+      EXPECT_EQ(32 - sar, s.ToInt32(s[0]->InputAt(2)));
+    }
+  }
+}
+
+
 TEST_F(InstructionSelectorTest, Word32AndWithUbfxImmediateForARMv7) {
   TRACED_FORRANGE(int32_t, width, 9, 23) {
     if (width == 16) continue;  // Uxth.