Add restrictions for volatile variables

.

Author: KorovinVlad

IGC/VectorCompiler/lib/GenXCodeGen/GenXVerify.cpp

@@ -1,6 +1,6 @@
 /*========================== begin_copyright_notice ============================
 
-Copyright (C) 2023 Intel Corporation
+Copyright (C) 2023-2024 Intel Corporation
 
 SPDX-License-Identifier: MIT
 
@@ -27,20 +27,20 @@ void GenXVerify::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
 }
 
-bool GenXVerify::ensure(const bool Cond, const Twine &Msg, const Instruction &I,
+bool GenXVerify::ensure(const bool Cond, const Twine &Msg, const Value &V,
                         const IsFatal IsFatal_) {
   if (LLVM_LIKELY(Cond))
     return true;
   if (IsFatal_ == IsFatal::Yes || OptAllFatal || !OptQuietNonFatal)
-    vc::diagnose(I.getContext(),
+    vc::diagnose(V.getContext(),
                  DbgPrefix + "[stage:" +
                      OptStage.getParser().getOption(
                          static_cast<int>(OptStage.getValue())) +
                      "]" +
                      (IsFatal_ == IsFatal::No
                           ? " (non-fatal, spec review required)"
                           : ""),
-                 Msg, DS_Warning, vc::WarningName::Generic, &I);
+                 Msg, DS_Warning, vc::WarningName::Generic, &V);
   if (IsFatal_ == IsFatal::Yes || OptAllFatal) {
     IsBroken = true;
     if (OptTerminationPolicy == Terminate::OnFirstError)
@@ -55,15 +55,29 @@ bool GenXVerify::ensure(const bool Cond, const Twine &Msg, const Instruction &I,
 
 bool GenXVerify::runOnModule(Module &M) {
   visit(M);
+  if (Stage == GenXVerifyStage::PostIrAdaptors)
+    for (const auto &GV : M.globals())
+      visitGlobalVariable(GV);
   if (OptTerminationPolicy != Terminate::No && IsBroken)
     terminate();
   return false;
 }
 
 void GenXVerify::visitGlobalVariable(const GlobalVariable &GV){
-    // TODO: add genx_volatile-attributed values check here.
-    //       please make sure to run this check under a proper InvariantsSet to
-    //       trigger it only at appropriate pipeline stage(s).
+  if (!GV.hasAttribute(genx::FunctionMD::GenXVolatile))
+    return;
+  ensure(GV.getAddressSpace() == vc::AddrSpace::Private,
+         "a volatile variable must reside in private address space", GV);
+  auto InvalidUser = llvm::find_if(GV.users(), [](const User *U) {
+    const auto *I = dyn_cast<Instruction>(U);
+    return !I || !(genx::isAVStore(I) || genx::isAVLoad(I));
+  });
+  if (InvalidUser == GV.user_end())
+    return;
+  ensure(false,
+         "a volatile variable may only be used in genx.vload/genx.vstore "
+         "intrinsics and volatile loads/stores instructions",
+         **InvalidUser);
 };
 
 void GenXVerify::visitCallInst(const CallInst &CI) {

IGC/VectorCompiler/lib/GenXCodeGen/GenXVerify.h

@@ -1,6 +1,6 @@
 /*========================== begin_copyright_notice ============================
 
-Copyright (C) 2023 Intel Corporation
+Copyright (C) 2023-2024 Intel Corporation
 
 SPDX-License-Identifier: MIT
 
@@ -73,7 +73,7 @@ class GenXVerify : public ModulePass,
   enum class IsFatal { No = 0, Yes = 1 };
 
   void verifyRegioning(const CallInst &, const unsigned);
-  bool ensure(const bool Cond, const Twine &Msg, const Instruction &I,
+  bool ensure(const bool Cond, const Twine &Msg, const Value &V,
               const IsFatal IsFatal_ = IsFatal::Yes);
   [[noreturn]] static void terminate();
 

IGC/VectorCompiler/test/GenXVerify/volatile.ll

@@ -0,0 +1,45 @@
+;=========================== begin_copyright_notice ============================
+;
+; Copyright (C) 2024 Intel Corporation
+;
+; SPDX-License-Identifier: MIT
+;
+;============================ end_copyright_notice =============================
+
+; RUN: %opt %use_old_pass_manager% -GenXVerify -genx-verify-terminate=no \
+; RUN: -genx-verify-all-fatal=1 -march=genx64 -mtriple=spir64-unknown-unknown \
+; RUN: -mcpu=Gen9 -genx-verify-stage=post-ir-adaptors -S < %s 2>&1 | FileCheck \
+; RUN: --check-prefixes=CHECK %s
+
+target datalayout = "e-p:64:64-p6:32:32-i64:64-n8:16:32:64"
+target triple = "genx64-unknown-unknown"
+
+; CHECK: warning: {{.+}} <@SLMGV = addrspace(3) {{.+}}>: a volatile variable must reside in private address space
+@SLMGV = addrspace(3) global <2 x i8> undef #0
+
+; CHECK: warning: {{.+}} @GV {{.+}} a volatile variable may only be used in genx.vload/genx.vstore intrinsics and volatile loads/stores instructions
+@GV = global <16 x i32> zeroinitializer, align 64 #1
+@ALIAS = global <16 x i32> addrspace(1)* addrspacecast (<16 x i32>* @GV to <16 x i32> addrspace(1)*)
+
+@INVALID = global <16 x float> zeroinitializer, align 64 #2
+@VALID = global <16 x float> zeroinitializer, align 64 #3
+
+define internal spir_func void @foo() {
+  ; CHECK: warning: {{.+}} %cst = {{.+}} a volatile variable may only be used in genx.vload/genx.vstore intrinsics and volatile loads/stores instructions
+  %cst = addrspacecast <16 x float>* @INVALID to <16 x float> addrspace(4)*
+
+  ; CHECK-NOT: warning
+  %ld.ic = tail call <16 x float> @llvm.genx.vload.v16f32.p0v16f32(<16 x float>* @VALID)
+  call void @llvm.genx.vstore.v16f32.p0v16f32(<16 x float> %ld.ic, <16 x float>* @VALID)
+  %ld.inst = load volatile <16 x float>, <16 x float>* @VALID
+  store volatile <16 x float> %ld.inst, <16 x float>* @VALID
+  ret void
+}
+
+declare <16 x float> @llvm.genx.vload.v16f32.p0v16f32(<16 x float>*)
+declare void @llvm.genx.vstore.v16f32.p0v16f32(<16 x float>, <16 x float>*)
+
+attributes #0 = { "VCByteOffset"="0" "VCGlobalVariable" "VCVolatile" "genx_byte_offset"="0" "genx_volatile" }
+attributes #1 = { "VCByteOffset"="256" "VCGlobalVariable" "VCVolatile" "genx_byte_offset"="256" "genx_volatile" }
+attributes #2 = { "VCByteOffset"="512" "VCGlobalVariable" "VCVolatile" "genx_byte_offset"="512" "genx_volatile" }
+attributes #3 = { "VCByteOffset"="1024" "VCGlobalVariable" "VCVolatile" "genx_byte_offset"="1024" "genx_volatile" }