Amend SingleElementVectorINTEL decoration use cases according to spec update (#1192)

DecorationSingleElementVectorINTEl now has one extra operand
representing number of pointer stars owned by the element of vector.
It helps to restore scalars after translation back. Eg:

<i32* x 1>** -> i32*** "VCSingleElementVector"="1"

Also it now can be applied to global variables.

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@4eb63bf

Author: DmitryBushev

llvm-spirv/lib/SPIRV/SPIRVReader.cpp

@@ -220,6 +220,30 @@ Value *SPIRVToLLVM::getTranslatedValue(SPIRVValue *BV) {
   return nullptr;
 }
 
+static llvm::Optional<llvm::Attribute>
+translateSEVMetadata(SPIRVValue *BV, llvm::LLVMContext &Context) {
+  llvm::Optional<llvm::Attribute> RetAttr;
+
+  if (!BV->hasDecorate(DecorationSingleElementVectorINTEL))
+    return RetAttr;
+
+  auto VecDecorateSEV = BV->getDecorations(DecorationSingleElementVectorINTEL);
+  assert(VecDecorateSEV.size() == 1 &&
+         "Entry must have no more than one SingleElementVectorINTEL "
+         "decoration");
+  auto *DecorateSEV = VecDecorateSEV.back();
+  auto LiteralCount = DecorateSEV->getLiteralCount();
+  assert(LiteralCount <= 1 && "SingleElementVectorINTEL decoration must "
+                              "have no more than one literal");
+
+  SPIRVWord IndirectLevelsOnElement =
+      (LiteralCount == 1) ? DecorateSEV->getLiteral(0) : 0;
+
+  RetAttr = Attribute::get(Context, kVCMetadata::VCSingleElementVector,
+                           std::to_string(IndirectLevelsOnElement));
+  return RetAttr;
+}
+
 IntrinsicInst *SPIRVToLLVM::getLifetimeStartIntrinsic(Instruction *I) {
   auto II = dyn_cast<IntrinsicInst>(I);
   if (II && II->getIntrinsicID() == Intrinsic::lifetime_start)
@@ -1510,6 +1534,10 @@ Value *SPIRVToLLVM::transValueWithoutDecoration(SPIRVValue *BV, Function *F,
         LVar->addAttribute(kVCMetadata::VCByteOffset, utostr(Offset));
       if (BVar->hasDecorate(DecorationVolatile))
         LVar->addAttribute(kVCMetadata::VCVolatile);
+      auto SEVAttr = translateSEVMetadata(BVar, LVar->getContext());
+      if (SEVAttr)
+        LVar->addAttribute(SEVAttr.getValue().getKindAsString(),
+                           SEVAttr.getValue().getValueAsString());
     }
 
     return Res;
@@ -3886,9 +3914,10 @@ bool SPIRVToLLVM::transVectorComputeMetadata(SPIRVFunction *BF) {
   if (BF->hasDecorate(DecorationSIMTCallINTEL, 0, &SIMTMode))
     F->addFnAttr(kVCMetadata::VCSIMTCall, std::to_string(SIMTMode));
 
-  auto SEVAttr = Attribute::get(*Context, kVCMetadata::VCSingleElementVector);
-  if (BF->hasDecorate(DecorationSingleElementVectorINTEL))
-    F->addAttributeAtIndex(AttributeList::ReturnIndex, SEVAttr);
+  auto SEVAttr = translateSEVMetadata(BF, F->getContext());
+
+  if (SEVAttr)
+    F->addAttributeAtIndex(AttributeList::ReturnIndex, SEVAttr.getValue());
 
   for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E;
        ++I) {
@@ -3905,8 +3934,9 @@ bool SPIRVToLLVM::transVectorComputeMetadata(SPIRVFunction *BF) {
                                       std::to_string(Kind));
       F->addParamAttr(ArgNo, Attr);
     }
-    if (BA->hasDecorate(DecorationSingleElementVectorINTEL))
-      F->addParamAttr(ArgNo, SEVAttr);
+    SEVAttr = translateSEVMetadata(BA, F->getContext());
+    if (SEVAttr)
+      F->addParamAttr(ArgNo, SEVAttr.getValue());
     if (BA->hasDecorate(internal::DecorationFuncParamDescINTEL)) {
       auto Desc =
           BA->getDecorationStringLiteral(internal::DecorationFuncParamDescINTEL)

llvm-spirv/lib/SPIRV/SPIRVWriter.cpp

@@ -122,6 +122,24 @@ static SPIRVMemoryModelKind getMemoryModel(Module &M) {
   return SPIRVMemoryModelKind::MemoryModelMax;
 }
 
+static void translateSEVDecoration(Attribute Sev, SPIRVValue *Val) {
+  assert(Sev.isStringAttribute() &&
+         Sev.getKindAsString() == kVCMetadata::VCSingleElementVector);
+
+  auto *Ty = Val->getType();
+  assert((Ty->isTypeBool() || Ty->isTypeFloat() || Ty->isTypeInt() ||
+          Ty->isTypePointer()) &&
+         "This decoration is valid only for Scalar or Pointer types");
+
+  if (Ty->isTypePointer()) {
+    SPIRVWord IndirectLevelsOnElement = 0;
+    Sev.getValueAsString().getAsInteger(0, IndirectLevelsOnElement);
+    Val->addDecorate(DecorationSingleElementVectorINTEL,
+                     IndirectLevelsOnElement);
+  } else
+    Val->addDecorate(DecorationSingleElementVectorINTEL);
+}
+
 LLVMToSPIRVBase::LLVMToSPIRVBase(SPIRVModule *SMod)
     : M(nullptr), Ctx(nullptr), BM(SMod), SrcLang(0), SrcLangVer(0) {
   DbgTran = std::make_unique<LLVMToSPIRVDbgTran>(nullptr, SMod, this);
@@ -725,14 +743,11 @@ void LLVMToSPIRVBase::transVectorComputeMetadata(Function *F) {
     BF->addDecorate(DecorationSIMTCallINTEL, SIMTMode);
   }
 
-  if (Attrs.hasRetAttr(kVCMetadata::VCSingleElementVector)) {
-    auto *RT = BF->getType();
-    (void)RT;
-    assert((RT->isTypeBool() || RT->isTypeFloat() || RT->isTypeInt() ||
-            RT->isTypePointer()) &&
-           "This decoration is valid only for Scalar or Pointer types");
-    BF->addDecorate(DecorationSingleElementVectorINTEL);
-  }
+  if (Attrs.hasRetAttr(kVCMetadata::VCSingleElementVector))
+    translateSEVDecoration(
+        Attrs.getAttributeAtIndex(AttributeList::ReturnIndex,
+                                  kVCMetadata::VCSingleElementVector),
+        BF);
 
   for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E;
        ++I) {
@@ -745,14 +760,9 @@ void LLVMToSPIRVBase::transVectorComputeMetadata(Function *F) {
           .getAsInteger(0, Kind);
       BA->addDecorate(DecorationFuncParamIOKindINTEL, Kind);
     }
-    if (Attrs.hasParamAttr(ArgNo, kVCMetadata::VCSingleElementVector)) {
-      auto *AT = BA->getType();
-      (void)AT;
-      assert((AT->isTypeBool() || AT->isTypeFloat() || AT->isTypeInt() ||
-              AT->isTypePointer()) &&
-             "This decoration is valid only for Scalar or Pointer types");
-      BA->addDecorate(DecorationSingleElementVectorINTEL);
-    }
+    if (Attrs.hasParamAttr(ArgNo, kVCMetadata::VCSingleElementVector))
+      translateSEVDecoration(
+          Attrs.getParamAttr(ArgNo, kVCMetadata::VCSingleElementVector), BA);
     if (Attrs.hasParamAttr(ArgNo, kVCMetadata::VCArgumentKind)) {
       SPIRVWord Kind;
       Attrs.getParamAttr(ArgNo, kVCMetadata::VCArgumentKind)
@@ -1534,6 +1544,10 @@ LLVMToSPIRVBase::transValueWithoutDecoration(Value *V, SPIRVBasicBlock *BB,
       }
       if (GV->hasAttribute(kVCMetadata::VCVolatile))
         BVar->addDecorate(DecorationVolatile);
+
+      if (GV->hasAttribute(kVCMetadata::VCSingleElementVector))
+        translateSEVDecoration(
+            GV->getAttribute(kVCMetadata::VCSingleElementVector), BVar);
     }
 
     mapValue(V, BVar);

llvm-spirv/test/transcoding/SPV_INTEL_vector_compute/decoration_single_element_vector.ll

@@ -12,16 +12,19 @@ target datalayout = "e-p:64:64-i64:64-n8:16:32"
 target triple = "spir64"
 
 
+@global_var = external global i32** #2
 
 ; SPV-DAG: Name [[def:[0-9]+]] "_Z24__cm_intrinsic_impl_sdivu2CMvb1_cS_"
 ; SPV-DAG: Name [[a:[0-9]+]] "a"
 ; SPV-DAG: Name [[b:[0-9]+]] "b"
+; SPV-DAG: Name [[glob:[0-9]+]] "global_var"
 ; SPV-DAG: Decorate [[def]] SingleElementVectorINTEL
 ; SPV-DAG: Decorate [[a]] SingleElementVectorINTEL
 ; SPV-DAG: Decorate [[b]] SingleElementVectorINTEL
+; SPV-DAG: Decorate [[glob]] SingleElementVectorINTEL 2
 
-; LLVM-DAG: "VCSingleElementVector" i8 @_Z24__cm_intrinsic_impl_sdivu2CMvb1_cS_(i8 "VCSingleElementVector" %a, i8 "VCSingleElementVector" %b)
-; LLVM-DAG: i8 @some.unknown.intrinsic(i8 "VCSingleElementVector", i8)
+; LLVM-DAG: "VCSingleElementVector"="0" i8 @_Z24__cm_intrinsic_impl_sdivu2CMvb1_cS_(i8 "VCSingleElementVector"="0" %a, i8 "VCSingleElementVector"="0" %b)
+; LLVM-DAG: i8 @some.unknown.intrinsic(i8 "VCSingleElementVector"="0", i8)
 ; Function Attrs: noinline norecurse nounwind readnone
 define dso_local "VCSingleElementVector" i8 @_Z24__cm_intrinsic_impl_sdivu2CMvb1_cS_(i8 "VCSingleElementVector" %a, i8 "VCSingleElementVector" %b) local_unnamed_addr #1 {
 entry:
@@ -47,4 +50,8 @@ entry:
 ; Function Attrs: nounwind readnone
 declare i8 @some.unknown.intrinsic(i8 "VCSingleElementVector", i8) #1
 
+; LLVM: "VCGlobalVariable"
+; LLVM-SAME: "VCSingleElementVector"="2"
+
 attributes #1 = { noinline norecurse nounwind readnone "VCFunction"}
+attributes #2 = { "VCGlobalVariable" "VCSingleElementVector"="2" }