[SYCL] Add supplemental tool for SPIR-V to LLVM-IR conversions

llvm/test/CMakeLists.txt

@@ -135,6 +135,7 @@ set(LLVM_TEST_DEPENDS
           opt
           sancov
           sanstats
+          spirv-to-ir-wrapper
           sycl-post-link
           split-file
           verify-uselistorder

llvm/test/tools/spirv-to-ir-wrapper/spirv-to-ir-wrapper.ll

@@ -0,0 +1,49 @@
+; Check for passthrough abilities
+; RUN: llvm-as %s -o %t.bc
+; RUN: spirv-to-ir-wrapper %t.bc -o %t_1.bc
+; RUN: llvm-dis %t_1.bc -o %t_1.ll
+; RUN: FileCheck %s --input-file %t_1.ll
+
+; Check for SPIR-V conversion
+; RUN: llvm-spirv %t.bc -o %t.spv
+; RUN: spirv-to-ir-wrapper %t.spv -o %t_2.bc
+; RUN: llvm-dis %t_2.bc -o %t_2.ll
+; RUN: FileCheck %s --input-file %t_2.ll
+
+; CHECK: target datalayout
+; CHECK-NEXT: target triple = "spir-unknown-unknown"
+; CHECK: Function Attrs: nounwind
+; CHECK-NEXT: define spir_kernel void @foo(i32 addrspace(1)* %a)
+; CHECK-NEXT: entry:
+; CHECK-NEXT: %a.addr = alloca i32 addrspace(1)*, align 4
+; CHECK-NEXT: store i32 addrspace(1)* %a, i32 addrspace(1)** %a.addr, align 4
+; CHECK-NEXT: ret void
+
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024"
+target triple = "spir-unknown-unknown"
+
+; Function Attrs: nounwind
+define spir_kernel void @foo(i32 addrspace(1)* %a) #0 !kernel_arg_addr_space !1 !kernel_arg_access_qual !2 !kernel_arg_type !3 !kernel_arg_base_type !4 !kernel_arg_type_qual !5 {
+entry:
+  %a.addr = alloca i32 addrspace(1)*, align 4
+  store i32 addrspace(1)* %a, i32 addrspace(1)** %a.addr, align 4
+  ret void
+}
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!opencl.enable.FP_CONTRACT = !{}
+!opencl.spir.version = !{!6}
+!opencl.ocl.version = !{!6}
+!opencl.used.extensions = !{!7}
+!opencl.used.optional.core.features = !{!7}
+!opencl.compiler.options = !{!7}
+
+!1 = !{i32 1}
+!2 = !{!"none"}
+!3 = !{!"int*"}
+!4 = !{!"int*"}
+!5 = !{!""}
+!6 = !{i32 1, i32 2}
+!7 = !{}
+

llvm/tools/spirv-to-ir-wrapper/CMakeLists.txt

@@ -0,0 +1,13 @@
+set(LLVM_LINK_COMPONENTS
+  Core
+  Support
+  SPIRVLib
+  )
+
+include_directories(
+  ${LLVM_EXTERNAL_LLVM_SPIRV_SOURCE_DIR}/include
+  )
+
+add_llvm_tool(spirv-to-ir-wrapper
+  spirv-to-ir-wrapper.cpp
+  )

llvm/tools/spirv-to-ir-wrapper/spirv-to-ir-wrapper.cpp

@@ -0,0 +1,138 @@
+//===--- spirv-to-ir-wrapper.cpp - Utility to convert to ir if needed -----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This utility checks if the input file is SPIR-V based.  If so, convert to IR
+// The input can be either SPIR-V or LLVM-IR.  When LLVM-IR, copy the file to
+// the specified output.
+//
+// Uses llvm-spirv to perform the conversion if needed.
+//
+// The output file is used to allow for proper input and output flow within
+// the driver toolchain.
+//
+// Usage: spirv-to-ir-wrapper input.spv -o output.bc
+//
+//===----------------------------------------------------------------------===//
+
+#include "LLVMSPIRVLib.h"
+#include "llvm/BinaryFormat/Magic.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/InitLLVM.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/Program.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/StringSaver.h"
+
+using namespace llvm;
+
+// InputFilename - The filename to read from.
+static cl::opt<std::string> InputFilename(cl::Positional,
+                                          cl::value_desc("<input spv file>"),
+                                          cl::desc("<input file>"));
+
+// Output - The filename to output to.
+static cl::opt<std::string> Output("o", cl::value_desc("output IR filename"),
+                                   cl::desc("output filename"));
+
+// LlvmSpirvOpts - The filename to output to.
+static cl::opt<std::string>
+    LlvmSpirvOpts("llvm-spirv-opts", cl::value_desc("llvm-spirv options"),
+                  cl::desc("options to pass to llvm-spirv"));
+
+static void error(const Twine &Message) {
+  llvm::errs() << "spirv-to-ir-wrapper: " << Message << '\n';
+  exit(1);
+}
+
+// Convert the SPIR-V to LLVM-IR.
+static int convertSPIRVToLLVMIR(const char *Argv0) {
+  // Find llvm-spirv.  It is expected this resides in the same directory
+  // as spirv-to-ir-wrapper.
+  StringRef ParentPath = llvm::sys::path::parent_path(Argv0);
+  llvm::ErrorOr<std::string> LlvmSpirvBinary =
+      llvm::sys::findProgramByName("llvm-spirv", ParentPath);
+  if (!LlvmSpirvBinary)
+    LlvmSpirvBinary = llvm::sys::findProgramByName("llvm-spirv");
+
+  SmallVector<StringRef, 6> LlvmSpirvArgs = {"llvm-spirv", "-r", InputFilename,
+                                             "-o", Output};
+
+  // Add any additional options specified by the user.
+  SmallVector<const char *, 8> TargetArgs;
+  llvm::BumpPtrAllocator BPA;
+  llvm::StringSaver S(BPA);
+  if (!LlvmSpirvOpts.empty()) {
+    // Tokenize the string.
+    llvm::cl::TokenizeGNUCommandLine(LlvmSpirvOpts, S, TargetArgs);
+    std::copy(TargetArgs.begin(), TargetArgs.end(),
+              std::back_inserter(LlvmSpirvArgs));
+  }
+
+  return llvm::sys::ExecuteAndWait(LlvmSpirvBinary.get(), LlvmSpirvArgs);
+}
+
+static int copyInputToOutput() {
+  return llvm::sys::fs::copy_file(InputFilename, Output).value();
+}
+
+static bool isSPIRVBinary(const std::string &File) {
+  auto FileOrError = MemoryBuffer::getFile(File, /*IsText=*/false,
+                                           /*RequiresNullTerminator=*/false);
+  if (!FileOrError)
+    return false;
+  std::unique_ptr<MemoryBuffer> FileBuffer = std::move(*FileOrError);
+  return SPIRV::isSpirvBinary(FileBuffer->getBuffer().str());
+}
+
+static bool isLLVMIRBinary(const std::string &File) {
+  if (File.size() < sizeof(unsigned))
+    return false;
+
+  StringRef Ext = llvm::sys::path::has_extension(File)
+                      ? llvm::sys::path::extension(File).drop_front()
+                      : "";
+  llvm::file_magic Magic;
+  llvm::identify_magic(File, Magic);
+
+  // Only .bc and bitcode files are to be considered.
+  return (Ext == "bc" || Magic == llvm::file_magic::bitcode);
+}
+
+static int checkInputFileIsAlreadyLLVM(const char *Argv0) {
+  StringRef Ext = llvm::sys::path::has_extension(InputFilename)
+                      ? llvm::sys::path::extension(InputFilename).drop_front()
+                      : "";
+  if (Ext == "bc" || isLLVMIRBinary(InputFilename))
+    return copyInputToOutput();
+  if (Ext == "spv" || isSPIRVBinary(InputFilename))
+    return convertSPIRVToLLVMIR(Argv0);
+
+  // We could not directly determine the input file, so we just copy it
+  // to the output file.
+  return copyInputToOutput();
+}
+
+int main(int argc, char **argv) {
+  InitLLVM X(argc, argv);
+
+  LLVMContext Context;
+  cl::ParseCommandLineOptions(argc, argv, "spirv-to-ir-wrapper\n");
+
+  if (InputFilename.empty())
+    error("No input file provided");
+
+  if (!llvm::sys::fs::exists(InputFilename))
+    error("Input file \'" + InputFilename + "\' not found");
+
+  if (Output.empty())
+    error("Output file not provided");
+
+  return checkInputFileIsAlreadyLLVM(argv[0]);
+}

sycl/CMakeLists.txt

@@ -229,6 +229,7 @@ add_custom_target(sycl-compiler
           llvm-spirv
           llvm-link
           llvm-objcopy
+          spirv-to-ir-wrapper
           sycl-post-link
           opencl-aot
 )
@@ -292,6 +293,7 @@ set( SYCL_TOOLCHAIN_DEPLOY_COMPONENTS
      llvm-spirv
      llvm-link
      llvm-objcopy
+     spirv-to-ir-wrapper
      sycl-post-link
      sycl-ls
      clang-resource-headers