Add IR constructs for preallocated (inalloca replacement)

Add llvm.call.preallocated.{setup,arg} instrinsics.
Add "preallocated" operand bundle which takes a token produced by llvm.call.preallocated.setup.
Add "preallocated" parameter attribute, which is like byval but without the copy.

Verifier changes for these IR constructs.

See https://github.com/rnk/llvm-project/blob/call-setup-docs/llvm/docs/CallSetup.md

Subscribers: hiraditya, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74651

1 files changed, 13 insertions, 7 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 4b8b0ec..9bdac5c4 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1303,6 +1303,9 @@ static uint64_t getRawAttributeMask(Attribute::AttrKind Val) {
   case Attribute::SanitizeMemTag:
     llvm_unreachable("sanitize_memtag attribute not supported in raw format");
     break;
+  case Attribute::Preallocated:
+    llvm_unreachable("preallocated attribute not supported in raw format");
+    break;
   }
   llvm_unreachable("Unsupported attribute type");
 }
@@ -1312,12 +1315,10 @@ static void addRawAttributeValue(AttrBuilder &B, uint64_t Val) {
 
   for (Attribute::AttrKind I = Attribute::None; I != Attribute::EndAttrKinds;
        I = Attribute::AttrKind(I + 1)) {
-    if (I == Attribute::SanitizeMemTag ||
-        I == Attribute::Dereferenceable ||
-        I == Attribute::DereferenceableOrNull ||
-        I == Attribute::ArgMemOnly ||
-        I == Attribute::AllocSize ||
-        I == Attribute::NoSync)
+    if (I == Attribute::SanitizeMemTag || I == Attribute::Dereferenceable ||
+        I == Attribute::DereferenceableOrNull || I == Attribute::ArgMemOnly ||
+        I == Attribute::AllocSize || I == Attribute::NoSync ||
+        I == Attribute::Preallocated)
       continue;
     if (uint64_t A = (Val & getRawAttributeMask(I))) {
       if (I == Attribute::Alignment)
@@ -1544,6 +1545,8 @@ static Attribute::AttrKind getAttrFromCode(uint64_t Code) {
     return Attribute::ImmArg;
   case bitc::ATTR_KIND_SANITIZE_MEMTAG:
     return Attribute::SanitizeMemTag;
+  case bitc::ATTR_KIND_PREALLOCATED:
+    return Attribute::Preallocated;
   }
 }
 
@@ -1659,8 +1662,11 @@ Error BitcodeReader::parseAttributeGroupBlock() {
           Attribute::AttrKind Kind;
           if (Error Err = parseAttrKind(Record[++i], &Kind))
             return Err;
-          if (Kind == Attribute::ByVal)
+          if (Kind == Attribute::ByVal) {
             B.addByValAttr(HasType ? getTypeByID(Record[++i]) : nullptr);
+          } else if (Kind == Attribute::Preallocated) {
+            B.addPreallocatedAttr(getTypeByID(Record[++i]));
+          }
         }
       }