[SPIRV][SPIRVPrepareGlobals] Convert llvm.embedded.module from a 0-element array to a 1-element array

llvm/lib/Target/SPIRV/CMakeLists.txt

@@ -41,6 +41,7 @@ add_llvm_target(SPIRVCodeGen
   SPIRVPreLegalizerCombiner.cpp
   SPIRVPostLegalizer.cpp
   SPIRVPrepareFunctions.cpp
+  SPIRVPrepareGlobals.cpp
   SPIRVRegisterBankInfo.cpp
   SPIRVRegisterInfo.cpp
   SPIRVRegularizer.cpp

llvm/lib/Target/SPIRV/SPIRV.h

@@ -31,6 +31,7 @@ FunctionPass *createSPIRVPreLegalizerCombiner();
 FunctionPass *createSPIRVPreLegalizerPass();
 FunctionPass *createSPIRVPostLegalizerPass();
 ModulePass *createSPIRVEmitIntrinsicsPass(SPIRVTargetMachine *TM);
+ModulePass *createSPIRVPrepareGlobalsPass();
 MachineFunctionPass *createSPIRVEmitNonSemanticDIPass(SPIRVTargetMachine *TM);
 InstructionSelector *
 createSPIRVInstructionSelector(const SPIRVTargetMachine &TM,
@@ -51,6 +52,7 @@ void initializeSPIRVLegalizePointerCastPass(PassRegistry &);
 void initializeSPIRVRegularizerPass(PassRegistry &);
 void initializeSPIRVMergeRegionExitTargetsPass(PassRegistry &);
 void initializeSPIRVPrepareFunctionsPass(PassRegistry &);
+void initializeSPIRVPrepareGlobalsPass(PassRegistry &);
 void initializeSPIRVStripConvergentIntrinsicsPass(PassRegistry &);
 void initializeSPIRVLegalizeImplicitBindingPass(PassRegistry &);
 } // namespace llvm

llvm/lib/Target/SPIRV/SPIRVPrepareGlobals.cpp

@@ -0,0 +1,68 @@
+//===-- SPIRVPrepareGlobals.cpp - Prepare IR SPIRV globals ------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// The pass transforms IR globals that cannot be trivially mapped to SPIRV
+// into something that is trival to lower.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SPIRV.h"
+
+#include "llvm/IR/Module.h"
+
+using namespace llvm;
+
+namespace {
+
+struct SPIRVPrepareGlobals : public ModulePass {
+  static char ID;
+  SPIRVPrepareGlobals() : ModulePass(ID) {}
+
+  StringRef getPassName() const override {
+    return "SPIRV prepare global variables";
+  }
+
+  bool runOnModule(Module &M) override;
+};
+
+bool tryExtendLLVMBitcodeMarker(GlobalVariable &Bitcode) {
+  assert(Bitcode.getName() == "llvm.embedded.module");
+
+  ArrayType *AT = cast<ArrayType>(Bitcode.getValueType());
+  if (AT->getNumElements() != 0)
+    return false;
+
+  ArrayType *AT1 = ArrayType::get(AT->getElementType(), 1);
+  Constant *OneEltInit = Constant::getNullValue(AT1);
+  Bitcode.replaceInitializer(OneEltInit);
+  return true;
+}
+
+bool SPIRVPrepareGlobals::runOnModule(Module &M) {
+  const bool IsAMD = M.getTargetTriple().getVendor() == Triple::AMD;
+  if (!IsAMD)
+    return false;
+
+  bool Changed = false;
+  if (GlobalVariable *Bitcode = M.getNamedGlobal("llvm.embedded.module"))
+    Changed |= tryExtendLLVMBitcodeMarker(*Bitcode);
+
+  return Changed;
+}
+char SPIRVPrepareGlobals::ID = 0;
+
+} // namespace
+
+INITIALIZE_PASS(SPIRVPrepareGlobals, "prepare-globals",
+                "SPIRV prepare global variables", false, false)
+
+namespace llvm {
+ModulePass *createSPIRVPrepareGlobalsPass() {
+  return new SPIRVPrepareGlobals();
+}
+} // namespace llvm

llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp

@@ -59,6 +59,7 @@ extern "C" LLVM_ABI LLVM_EXTERNAL_VISIBILITY void LLVMInitializeSPIRVTarget() {
   initializeSPIRVEmitIntrinsicsPass(PR);
   initializeSPIRVEmitNonSemanticDIPass(PR);
   initializeSPIRVPrepareFunctionsPass(PR);
+  initializeSPIRVPrepareGlobalsPass(PR);
   initializeSPIRVStripConvergentIntrinsicsPass(PR);
 }
 
@@ -172,6 +173,7 @@ void SPIRVPassConfig::addIRPasses() {
 
   addPass(createSPIRVRegularizerPass());
   addPass(createSPIRVPrepareFunctionsPass(TM));
+  addPass(createSPIRVPrepareGlobalsPass());
 }
 
 void SPIRVPassConfig::addISelPrepare() {

llvm/test/CodeGen/SPIRV/fembed-bitcode-marker.ll

@@ -0,0 +1,24 @@
+; Expanding the bitcode marker works only for AMD at the moment.
+; RUN: not llc -verify-machineinstrs -mtriple=spirv-unknown-unknown %s -o -
+; RUN: llc -verify-machineinstrs -mtriple=spirv64-amd-amdhsa %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -mtriple=spirv64-amd-amdhsa %s -o - -filetype=obj | spirv-val %}
+;
+; Verify that we lower the embedded bitcode
+
+@llvm.embedded.module = private addrspace(1) constant [0 x i8] zeroinitializer, section ".llvmbc", align 1
+@llvm.compiler.used = appending addrspace(1) global [1 x ptr addrspace(4)] [ptr addrspace(4) addrspacecast (ptr addrspace(1) @llvm.embedded.module to ptr addrspace(4))], section "llvm.metadata"
+
+; CHECK: OpName %[[#LLVM_EMBEDDED_MODULE:]] "llvm.embedded.module"
+; CHECK: OpDecorate %[[#LLVM_EMBEDDED_MODULE]] Constant
+; CHECK: %[[#UCHAR:]] = OpTypeInt 8 0
+; CHECK: %[[#UINT:]] = OpTypeInt 32 0
+; CHECK: %[[#ONE:]] = OpConstant %[[#UINT]] 1
+; CHECK: %[[#UCHAR_ARR_1:]] = OpTypeArray %[[#UCHAR]] %[[#ONE]]
+; CHECK: %[[#UCHAR_ARR_1_PTR:]] = OpTypePointer CrossWorkgroup %[[#UCHAR_ARR_1]]
+; CHECK: %[[#CONST_UCHAR_ARR_1:]] = OpConstantNull %[[#UCHAR_ARR_1]]
+; CHECK: %[[#LLVM_EMBEDDED_MODULE]] = OpVariable %[[#UCHAR_ARR_1_PTR]] CrossWorkgroup %[[#CONST_UCHAR_ARR_1]]
+
+define spir_kernel void @foo() {
+entry:
+  ret void
+}

llvm/test/CodeGen/SPIRV/fembed-bitcode.ll

@@ -0,0 +1,32 @@
+; RUN: llc -verify-machineinstrs -mtriple=spirv-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -mtriple=spirv-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+; RUN: llc -verify-machineinstrs -mtriple=spirv64-amd-amdhsa %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -mtriple=spirv64-amd-amdhsa %s -o - -filetype=obj | spirv-val %}
+;
+; Verify that we can lower the embedded module and cmdline.
+
+@llvm.embedded.module = private addrspace(1) constant [4 x i8] c"BC\C0\DE", section ".llvmbc", align 1
+@llvm.cmdline = private addrspace(1) constant [5 x i8] c"-cc1\00", section ".llvmcmd", align 1
+@llvm.compiler.used = appending addrspace(1) global [2 x ptr addrspace(4)] [ptr addrspace(4) addrspacecast (ptr addrspace(1) @llvm.embedded.module to ptr addrspace(4)), ptr addrspace(4) addrspacecast (ptr addrspace(1) @llvm.cmdline to ptr addrspace(4))], section "llvm.metadata"
+
+; CHECK: OpName %[[#LLVM_EMBEDDED_MODULE:]] "llvm.embedded.module"
+; CHECK: OpName %[[#LLVM_CMDLINE:]] "llvm.cmdline"
+; CHECK: OpDecorate %[[#LLVM_EMBEDDED_MODULE]] Constant
+; CHECK: OpDecorate %[[#LLVM_CMDLINE]] Constant
+; CHECK: %[[#UCHAR:]] = OpTypeInt 8 0
+; CHECK: %[[#UINT:]] = OpTypeInt 32 0
+; CHECK: %[[#FIVE:]] = OpConstant %[[#UINT]] 5
+; CHECK: %[[#UCHAR_ARR_5:]] = OpTypeArray %[[#UCHAR]] %[[#FIVE]]
+; CHECK: %[[#FOUR:]] = OpConstant %[[#UINT]] 4
+; CHECK: %[[#UCHAR_ARR_4:]] = OpTypeArray %[[#UCHAR]] %[[#FOUR]]
+; CHECK: %[[#UCHAR_ARR_5_PTR:]] = OpTypePointer CrossWorkgroup %[[#UCHAR_ARR_5]]
+; CHECK: %[[#UCHAR_ARR_4_PTR:]] = OpTypePointer CrossWorkgroup %[[#UCHAR_ARR_4]]
+; CHECK: %[[#CONST_UCHAR_ARR_4:]] = OpConstantComposite %[[#UCHAR_ARR_4]]
+; CHECK: %[[#LLVM_EMBEDDED_MODULE]] = OpVariable %[[#UCHAR_ARR_4_PTR]] CrossWorkgroup %[[#CONST_UCHAR_ARR_4]]
+; CHECK: %[[#CONST_UCHAR_ARR_5:]] = OpConstantComposite %[[#UCHAR_ARR_5]]
+; CHECK: %[[#LLVM_CMDLINE]] = OpVariable %[[#UCHAR_ARR_5_PTR]] CrossWorkgroup %[[#CONST_UCHAR_ARR_5]]
+
+define spir_kernel void @foo() {
+entry:
+  ret void
+}

llvm/test/CodeGen/SPIRV/llc-pipeline.ll

@@ -31,6 +31,7 @@
 ; SPIRV-O0-NEXT:      Expand reduction intrinsics
 ; SPIRV-O0-NEXT:      SPIR-V Regularizer
 ; SPIRV-O0-NEXT:    SPIRV prepare functions
+; SPIRV-O0-NEXT:    SPIRV prepare global variables
 ; SPIRV-O0-NEXT:    FunctionPass Manager
 ; SPIRV-O0-NEXT:      Lower invoke and unwind, for unwindless code generators
 ; SPIRV-O0-NEXT:      Remove unreachable blocks from the CFG
@@ -130,6 +131,7 @@
 ; SPIRV-Opt-NEXT:      Expand reduction intrinsics
 ; SPIRV-Opt-NEXT:      SPIR-V Regularizer
 ; SPIRV-Opt-NEXT:    SPIRV prepare functions
+; SPIRV-Opt-NEXT:    SPIRV prepare global variables
 ; SPIRV-Opt-NEXT:    FunctionPass Manager
 ; SPIRV-Opt-NEXT:      Dominator Tree Construction
 ; SPIRV-Opt-NEXT:      Natural Loop Information