[llvm] 28b9771 - [OpaquePtr] Make GEPs work with opaque pointers

[Arthur Eubanks via llvm-commits]

Author: Arthur Eubanks
Date: 2021-05-19T12:39:37-07:00
New Revision: 28b9771472fa3df2568b6c5de1a9726680d940d3

URL: https://github.com/llvm/llvm-project/commit/28b9771472fa3df2568b6c5de1a9726680d940d3
DIFF: https://github.com/llvm/llvm-project/commit/28b9771472fa3df2568b6c5de1a9726680d940d3.diff

LOG: [OpaquePtr] Make GEPs work with opaque pointers

No verifier changes needed, the verifier currently doesn't check that
the pointer operand's pointee type matches the GEP type. There is a
similar check in GetElementPtrInst::Create() though.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102744

Added: 
    

Modified: 
    llvm/include/llvm/IR/Instructions.h
    llvm/lib/AsmParser/LLParser.cpp
    llvm/lib/Bitcode/Reader/BitcodeReader.cpp
    llvm/test/Assembler/opaque-ptr.ll

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/IR/Instructions.h b/llvm/include/llvm/IR/Instructions.h
index 52b8bf5cf0803..1ab5ac028ac96 100644
--- a/llvm/include/llvm/IR/Instructions.h
+++ b/llvm/include/llvm/IR/Instructions.h
@@ -933,13 +933,13 @@ class GetElementPtrInst : public Instruction {
                                    const Twine &NameStr = "",
                                    Instruction *InsertBefore = nullptr) {
     unsigned Values = 1 + unsigned(IdxList.size());
-    if (!PointeeType)
+    if (!PointeeType) {
       PointeeType =
           cast<PointerType>(Ptr->getType()->getScalarType())->getElementType();
-    else
-      assert(
-          PointeeType ==
-          cast<PointerType>(Ptr->getType()->getScalarType())->getElementType());
+    } else {
+      assert(cast<PointerType>(Ptr->getType()->getScalarType())
+                 ->isOpaqueOrPointeeTypeMatches(PointeeType));
+    }
     return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
                                           NameStr, InsertBefore);
   }
@@ -949,13 +949,13 @@ class GetElementPtrInst : public Instruction {
                                    const Twine &NameStr,
                                    BasicBlock *InsertAtEnd) {
     unsigned Values = 1 + unsigned(IdxList.size());
-    if (!PointeeType)
+    if (!PointeeType) {
       PointeeType =
           cast<PointerType>(Ptr->getType()->getScalarType())->getElementType();
-    else
-      assert(
-          PointeeType ==
-          cast<PointerType>(Ptr->getType()->getScalarType())->getElementType());
+    } else {
+      assert(cast<PointerType>(Ptr->getType()->getScalarType())
+                 ->isOpaqueOrPointeeTypeMatches(PointeeType));
+    }
     return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
                                           NameStr, InsertAtEnd);
   }

diff  --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 2f85e8de575f9..a4bb423a94233 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -7741,7 +7741,7 @@ int LLParser::parseGetElementPtr(Instruction *&Inst, PerFunctionState &PFS) {
   if (!BasePointerType)
     return error(Loc, "base of getelementptr must be a pointer");
 
-  if (Ty != BasePointerType->getElementType()) {
+  if (!BasePointerType->isOpaqueOrPointeeTypeMatches(Ty)) {
     return error(
         ExplicitTypeLoc,
         typeComparisonErrorMessage(

diff  --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index b2794b38bd4ea..c61d66f8f4a44 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -4168,7 +4168,8 @@ Error BitcodeReader::parseFunctionBody(Function *F) {
       if (!Ty) {
         std::tie(FullTy, Ty) =
             getPointerElementTypes(FullBaseTy->getScalarType());
-      } else if (Ty != getPointerElementFlatType(FullBaseTy->getScalarType()))
+      } else if (!cast<PointerType>(FullBaseTy->getScalarType())
+                      ->isOpaqueOrPointeeTypeMatches(Ty))
         return error(
             "Explicit gep type does not match pointee type of pointer operand");
 

diff  --git a/llvm/test/Assembler/opaque-ptr.ll b/llvm/test/Assembler/opaque-ptr.ll
index 95a5a53e80b71..1fb0c5da8eafd 100644
--- a/llvm/test/Assembler/opaque-ptr.ll
+++ b/llvm/test/Assembler/opaque-ptr.ll
@@ -40,3 +40,11 @@ define void @store(ptr %a, i32 %i) {
     store i32 %i, ptr %a
     ret void
 }
+
+; CHECK: define void @gep(ptr %a)
+; CHECK:     %b = getelementptr i8, ptr %a, i32 2
+; CHECK:     ret void
+define void @gep(ptr %a) {
+    %b = getelementptr i8, ptr %a, i32 2
+    ret void
+}