[SPIRV] Add type inference of function parameters by call instances

[VyacheslavLevytskyy]

This PR adds type inference of function parameters by call instances. Two use cases that demonstrate the problem are added.

[llvmbot]

@llvm/pr-subscribers-backend-spir-v

Author: Vyacheslav Levytskyy (VyacheslavLevytskyy)

Changes

This PR adds type inference of function parameters by call instances. Two use cases that demonstrate the problem are added.

---

Full diff: https://github.com/llvm/llvm-project/pull/85077.diff

5 Files Affected:

• (modified) llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp (+1-1)
• (modified) llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp (+62)
• (modified) llvm/lib/Target/SPIRV/SPIRVUtils.h (+5)
• (added) llvm/test/CodeGen/SPIRV/pointers/type-deduce-args-rev.ll (+28)
• (added) llvm/test/CodeGen/SPIRV/pointers/type-deduce-args.ll (+28)

diff --git a/llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp b/llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp
index f1fbe2ba1bc416..77319f58ff4d97 100644
--- a/llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp
@@ -209,7 +209,7 @@ static SPIRVType *getArgSPIRVType(const Function &F, unsigned ArgIdx,
   // spv_assign_ptr_type intrinsic or otherwise use default pointer element
   // type.
   Argument *Arg = F.getArg(ArgIdx);
-  if (Arg->hasByValAttr() || Arg->hasByRefAttr()) {
+  if (HasPointeeTypeAttr(Arg)) {
     Type *ByValRefType = Arg->hasByValAttr() ? Arg->getParamByValType()
                                              : Arg->getParamByRefType();
     SPIRVType *ElementType = GR->getOrCreateSPIRVType(ByValRefType, MIRBuilder);
diff --git a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
index c5b901235402c1..e9099fac1c1a3c 100644
--- a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
@@ -91,6 +91,7 @@ class SPIRVEmitIntrinsics
                                         IRBuilder<> &B);
   void insertPtrCastOrAssignTypeInstr(Instruction *I, IRBuilder<> &B);
   void processGlobalValue(GlobalVariable &GV, IRBuilder<> &B);
+  void processParamTypes(Function *F, IRBuilder<> &B);
 
 public:
   static char ID;
@@ -794,6 +795,62 @@ void SPIRVEmitIntrinsics::processInstrAfterVisit(Instruction *I,
   }
 }
 
+void SPIRVEmitIntrinsics::processParamTypes(Function *F, IRBuilder<> &B) {
+  DenseMap<unsigned, Argument *> Args;
+  unsigned i = 0;
+  for (Argument &Arg : F->args()) {
+    if (isUntypedPointerTy(Arg.getType()) &&
+        DeducedElTys.find(&Arg) == DeducedElTys.end() &&
+        !HasPointeeTypeAttr(&Arg))
+      Args[i++] = &Arg;
+  }
+  if (i == 0)
+    return;
+
+  // Args contains opaque pointers without element type definition
+  B.SetInsertPointPastAllocas(F);
+  std::unordered_set<Value *> Visited;
+  for (User *U : F->users()) {
+    CallInst *CI = dyn_cast<CallInst>(U);
+    if (!CI)
+      continue;
+    for (unsigned OpIdx = 0; OpIdx < CI->arg_size() && Args.size() > 0;
+         OpIdx++) {
+      auto It = Args.find(OpIdx);
+      Argument *Arg = It == Args.end() ? nullptr : It->second;
+      if (!Arg)
+        continue;
+      Value *OpArg = CI->getArgOperand(OpIdx);
+      if (!isPointerTy(OpArg->getType()))
+        continue;
+      // maybe we already know the operand's element type
+      auto DeducedIt = DeducedElTys.find(OpArg);
+      Type *ElemTy = DeducedIt == DeducedElTys.end() ? nullptr : DeducedIt->second;
+      if (!ElemTy) {
+        for (User *OpU : OpArg->users()) {
+          if (Instruction *Inst = dyn_cast<Instruction>(OpU)) {
+            Visited.clear();
+            ElemTy = deduceElementTypeHelper(Inst, Visited, DeducedElTys);
+            if (ElemTy)
+              break;
+          }
+        }
+      }
+      if (ElemTy) {
+        unsigned AddressSpace = getPointerAddressSpace(Arg->getType());
+        CallInst *AssignPtrTyCI = buildIntrWithMD(
+            Intrinsic::spv_assign_ptr_type, {Arg->getType()},
+            Constant::getNullValue(ElemTy), Arg, {B.getInt32(AddressSpace)}, B);
+        DeducedElTys[AssignPtrTyCI] = ElemTy;
+        DeducedElTys[Arg] = ElemTy;
+        Args.erase(It);
+      }
+    }
+    if (Args.size() == 0)
+      break;
+  }
+}
+
 bool SPIRVEmitIntrinsics::runOnFunction(Function &Func) {
   if (Func.isDeclaration())
     return false;
@@ -839,6 +896,11 @@ bool SPIRVEmitIntrinsics::runOnFunction(Function &Func) {
       continue;
     processInstrAfterVisit(I, B);
   }
+
+  // check if function parameter types are set
+  if (!F->isIntrinsic())
+    processParamTypes(F, B);
+
   return true;
 }
 
diff --git a/llvm/lib/Target/SPIRV/SPIRVUtils.h b/llvm/lib/Target/SPIRV/SPIRVUtils.h
index d5ed501def9986..eb87349f0941c5 100644
--- a/llvm/lib/Target/SPIRV/SPIRVUtils.h
+++ b/llvm/lib/Target/SPIRV/SPIRVUtils.h
@@ -126,5 +126,10 @@ inline unsigned getPointerAddressSpace(const Type *T) {
              : cast<TypedPointerType>(SubT)->getAddressSpace();
 }
 
+// Return true if the Argument is decorated with a pointee type
+inline bool HasPointeeTypeAttr(Argument *Arg) {
+  return Arg->hasByValAttr() || Arg->hasByRefAttr();
+}
+
 } // namespace llvm
 #endif // LLVM_LIB_TARGET_SPIRV_SPIRVUTILS_H
diff --git a/llvm/test/CodeGen/SPIRV/pointers/type-deduce-args-rev.ll b/llvm/test/CodeGen/SPIRV/pointers/type-deduce-args-rev.ll
new file mode 100644
index 00000000000000..3f8edfef78b03c
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/pointers/type-deduce-args-rev.ll
@@ -0,0 +1,28 @@
+; RUN: llc -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s --check-prefix=CHECK-SPIRV
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv32-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+; CHECK-SPIRV-DAG: OpName %[[FooArg:.*]] "known_type_ptr"
+; CHECK-SPIRV-DAG: OpName %[[Foo:.*]] "foo"
+; CHECK-SPIRV-DAG: OpName %[[ArgToDeduce:.*]] "unknown_type_ptr"
+; CHECK-SPIRV-DAG: OpName %[[Bar:.*]] "bar"
+; CHECK-SPIRV-DAG: %[[Long:.*]] = OpTypeInt 32 0
+; CHECK-SPIRV-DAG: %[[Void:.*]] = OpTypeVoid
+; CHECK-SPIRV-DAG: %[[LongPtr:.*]] = OpTypePointer CrossWorkgroup %[[Long]]
+; CHECK-SPIRV-DAG: %[[Fun:.*]] = OpTypeFunction %[[Void]] %[[LongPtr]]
+; CHECK-SPIRV: %[[Bar]] = OpFunction %[[Void]] None %[[Fun]]
+; CHECK-SPIRV: %[[ArgToDeduce]] = OpFunctionParameter %[[LongPtr]]
+; CHECK-SPIRV: OpFunctionCall %[[Void]] %[[Foo]] %[[ArgToDeduce]]
+; CHECK-SPIRV: %[[Foo]] = OpFunction %[[Void]] None %[[Fun]]
+; CHECK-SPIRV: %[[FooArg]] = OpFunctionParameter %[[LongPtr]]
+
+define spir_kernel void @bar(ptr addrspace(1) %unknown_type_ptr) {
+entry:
+  %elem = getelementptr inbounds i32, ptr addrspace(1) %unknown_type_ptr, i64 0
+  call spir_func void @foo(ptr addrspace(1) %unknown_type_ptr)
+  ret void
+}
+
+define void @foo(ptr addrspace(1) %known_type_ptr) {
+entry:
+  ret void
+}
diff --git a/llvm/test/CodeGen/SPIRV/pointers/type-deduce-args.ll b/llvm/test/CodeGen/SPIRV/pointers/type-deduce-args.ll
new file mode 100644
index 00000000000000..be8582f9226d5c
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/pointers/type-deduce-args.ll
@@ -0,0 +1,28 @@
+; RUN: llc -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s --check-prefix=CHECK-SPIRV
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv32-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+; CHECK-SPIRV-DAG: OpName %[[FooArg:.*]] "known_type_ptr"
+; CHECK-SPIRV-DAG: OpName %[[Foo:.*]] "foo"
+; CHECK-SPIRV-DAG: OpName %[[ArgToDeduce:.*]] "unknown_type_ptr"
+; CHECK-SPIRV-DAG: OpName %[[Bar:.*]] "bar"
+; CHECK-SPIRV-DAG: %[[Long:.*]] = OpTypeInt 32 0
+; CHECK-SPIRV-DAG: %[[Void:.*]] = OpTypeVoid
+; CHECK-SPIRV-DAG: %[[LongPtr:.*]] = OpTypePointer CrossWorkgroup %[[Long]]
+; CHECK-SPIRV-DAG: %[[Fun:.*]] = OpTypeFunction %[[Void]] %[[LongPtr]]
+; CHECK-SPIRV: %[[Foo]] = OpFunction %[[Void]] None %[[Fun]]
+; CHECK-SPIRV: %[[FooArg]] = OpFunctionParameter %[[LongPtr]]
+; CHECK-SPIRV: %[[Bar]] = OpFunction %[[Void]] None %[[Fun]]
+; CHECK-SPIRV: %[[ArgToDeduce]] = OpFunctionParameter %[[LongPtr]]
+; CHECK-SPIRV: OpFunctionCall %[[Void]] %[[Foo]] %[[ArgToDeduce]]
+
+define void @foo(ptr addrspace(1) %known_type_ptr) {
+entry:
+  ret void
+}
+
+define spir_kernel void @bar(ptr addrspace(1) %unknown_type_ptr) {
+entry:
+  %elem = getelementptr inbounds i32, ptr addrspace(1) %unknown_type_ptr, i64 0
+  call spir_func void @foo(ptr addrspace(1) %unknown_type_ptr)
+  ret void
+}

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[michalpaszkowski]

Thank you for the patch! LGTM! No regressions in OpenCL CTS. Two new tests pass SPIR-V validation: basic/progvar_prog_scope_misc, basic/vstore_private.