Subzero: ARM32: lowering of vector insert and extract.

src/IceTargetLoweringARM32.cpp

Index: src/IceTargetLoweringARM32.cpp
diff --git a/src/IceTargetLoweringARM32.cpp b/src/IceTargetLoweringARM32.cpp
index 72ba954e5a1f127952489fc635234ede22d0c013..4f08e5f1815edee0eced24c5b344cedfc8c56ff0 100644
--- a/src/IceTargetLoweringARM32.cpp
+++ b/src/IceTargetLoweringARM32.cpp
@@ -297,6 +297,7 @@ void TargetARM32::staticInit(GlobalContext *Ctx) {
   llvm::SmallBitVector Float32Registers(RegARM32::Reg_NUM);
   llvm::SmallBitVector Float64Registers(RegARM32::Reg_NUM);
   llvm::SmallBitVector VectorRegisters(RegARM32::Reg_NUM);
+  llvm::SmallBitVector QtoSRegisters(RegARM32::Reg_NUM);
   llvm::SmallBitVector InvalidRegisters(RegARM32::Reg_NUM);
   for (int i = 0; i < RegARM32::Reg_NUM; ++i) {
     const auto &Entry = RegARM32::RegTable[i];
@@ -306,6 +307,7 @@ void TargetARM32::staticInit(GlobalContext *Ctx) {
     Float64Registers[i] = Entry.IsFP64;
     VectorRegisters[i] = Entry.IsVec128;
     RegisterAliases[i].resize(RegARM32::Reg_NUM);
+    QtoSRegisters[i] = Entry.IsVec128 && i < RegARM32::Reg_q8;
     for (int j = 0; j < Entry.NumAliases; ++j) {
       assert(i == j || !RegisterAliases[i][Entry.Aliases[j]]);
       RegisterAliases[i].set(Entry.Aliases[j]);
@@ -341,6 +343,7 @@ void TargetARM32::staticInit(GlobalContext *Ctx) {
   TypeToRegisterSet[IceType_v8i16] = VectorRegisters;
   TypeToRegisterSet[IceType_v4i32] = VectorRegisters;
   TypeToRegisterSet[IceType_v4f32] = VectorRegisters;
+  TypeToRegisterSet[RegARM32::RCARM32_QtoS] = QtoSRegisters;
 
   for (size_t i = 0; i < llvm::array_lengthof(TypeToRegisterSet); ++i)
     TypeToRegisterSetUnfiltered[i] = TypeToRegisterSet[i];
@@ -3830,8 +3833,35 @@ void TargetARM32::lowerCast(const InstCast *Inst) {
   }
 }
 
-void TargetARM32::lowerExtractElement(const InstExtractElement *Inst) {
-  UnimplementedLoweringError(this, Inst);
+void TargetARM32::lowerExtractElement(const InstExtractElement *Instr) {
+  Variable *Dest = Instr->getDest();
+  auto DestTy = Dest->getType();
+
+  if (Dest->isRematerializable()) {
+    Context.insert<InstFakeDef>(Dest);
+    return;
+  }
+
+  Variable *Src0 = legalizeToReg(Instr->getSrc(0));
+  Operand *Src1 = Instr->getSrc(1);
+
+  if (const auto *Imm = llvm::dyn_cast<ConstantInteger32>(Src1)) {
+    const uint32_t Index = Imm->getValue();
+    Variable *T = makeReg(DestTy);
+    Variable *TSrc0 = makeReg(Src0->getType());

[Jim Stichnoth, 2016/02/03 22:32:21]

Bikeshed: the name "TSrc0" strikes me as unlike any other variable name here. 
I'm too lazy to figure out a better name, any ideas John?

+
+    if (isFloatingType(DestTy)) {
+      // We need to make sure the source is in a suitable register.
+      TSrc0->setRegClass(RegARM32::RCARM32_QtoS);

[Jim Stichnoth, 2016/02/03 22:32:21]

Another possibility is to move more stuff into this conditional:
if (isFloatingType(DestTy)) {
  Variable *TSrc0 = makeReg(Src0->getType());
  TSrc0->setRegClass(RegARM32::RCARM32_QtoS);
  _mov(TSrc0, Src0);
  Src0 = TSrc0;
}

[John, 2016/02/04 15:23:57]

+1

+    }
+
+    _mov(TSrc0, Src0);
+    _extractelement(T, TSrc0, Index);
+    _mov(Dest, T);
+    return;
+  } else {
+    assert(false && "extractelement requires a constant index");
+  }
 }
 
 namespace {
@@ -4225,8 +4255,34 @@ void TargetARM32::lowerIcmp(const InstIcmp *Inst) {
   return;
 }
 
-void TargetARM32::lowerInsertElement(const InstInsertElement *Inst) {
-  UnimplementedLoweringError(this, Inst);
+void TargetARM32::lowerInsertElement(const InstInsertElement *Instr) {
+  Variable *Dest = Instr->getDest();
+  auto DestTy = Dest->getType();
+
+  if (Dest->isRematerializable()) {
+    Context.insert<InstFakeDef>(Dest);
+    return;
+  }
+
+  Variable *Src0 = legalizeToReg(Instr->getSrc(0));
+  Variable *Src1 = legalizeToReg(Instr->getSrc(1));
+  Operand *Src2 = Instr->getSrc(2);
+
+  if (const auto *Imm = llvm::dyn_cast<ConstantInteger32>(Src2)) {
+    auto Index = Imm->getValue();
+    Variable *T = makeReg(DestTy);
+
+    if (isFloatingType(DestTy)) {
+      T->setRegClass(RegARM32::RCARM32_QtoS);
+    }
+
+    _mov(T, Src0);
+    _insertelement(T, Src1, Index);
+    _set_dest_redefined();
+    _mov(Dest, T);
+    return;
+  }
+  assert(false && "insertelement requires a constant index");
 }
 
 namespace {