AMDGPU/SI: Don't crash on anonymous GlobalValues

[• tstellarAMD]

Summary

We need to call AsmPrinter::getNameWithPrefix() in order to handle
anonymous GlobalValues (e.g. @0, @1).

[b-sumner]

I'd replace argument name AsmPrinter with AP to match the existing style.

[arsenm]

A better name for the test would be anonymous-gv.

Can you also add a test that uses an anonymous kernel

[• tstellarAMD]

Fix coding style and anonymous functions.

[b-sumner]

Looks good to me.

[arsenm]

test/CodeGen/AMDGPU/anonymous-gv.ll

5–15

The generated anonymous names should be checked

lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp

 }
 
 void AMDGPUAsmPrinter::EmitFunctionEntryLabel() {
   const SIMachineFunctionInfo *MFI = MF->getInfo<SIMachineFunctionInfo>();
   const AMDGPUSubtarget &STM = MF->getSubtarget<AMDGPUSubtarget>();
   if (MFI->isKernel() && STM.isAmdCodeObjectV2()) {
     AMDGPUTargetStreamer *TS =
         static_cast<AMDGPUTargetStreamer *>(OutStreamer->getTargetStreamer());
-    TS->EmitAMDGPUSymbolType(CurrentFnSym->getName(),
-                             ELF::STT_AMDGPU_HSA_KERNEL);
+    SmallString<128> SymbolName;
+    getNameWithPrefix(SymbolName, MF->getFunction()),
+    TS->EmitAMDGPUSymbolType(SymbolName, ELF::STT_AMDGPU_HSA_KERNEL);
   }
 
   AsmPrinter::EmitFunctionEntryLabel();
 }
 
 void AMDGPUAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
 
   // Group segment variables aren't emitted in HSA.

lib/Target/AMDGPU/AMDGPUMCInstLower.h

 //===- AMDGPUMCInstLower.h MachineInstr Lowering Interface ------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H
 #define LLVM_LIB_TARGET_AMDGPU_AMDGPUMCINSTLOWER_H
 
 namespace llvm {
 
 class AMDGPUSubtarget;
+class AsmPrinter;
 class MachineInstr;
 class MCContext;
 class MCInst;
 
 class AMDGPUMCInstLower {
   MCContext &Ctx;
   const AMDGPUSubtarget &ST;
+  const AsmPrinter ≈
 
 public:
-  AMDGPUMCInstLower(MCContext &ctx, const AMDGPUSubtarget &ST);
+  AMDGPUMCInstLower(MCContext &ctx, const AMDGPUSubtarget &ST,
+                    const AsmPrinter &AP);
 
   /// \brief Lower a MachineInstr to an MCInst
   void lower(const MachineInstr *MI, MCInst &OutMI) const;
 
 };
 
 } // End namespace llvm
 
 #endif

lib/Target/AMDGPU/AMDGPUMCInstLower.cpp

 #include "llvm/MC/MCObjectStreamer.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
 #include <algorithm>
 
 using namespace llvm;
 
-AMDGPUMCInstLower::AMDGPUMCInstLower(MCContext &ctx, const AMDGPUSubtarget &st):
-  Ctx(ctx), ST(st) { }
+AMDGPUMCInstLower::AMDGPUMCInstLower(MCContext &ctx, const AMDGPUSubtarget &st,
+                                     const AsmPrinter &ap):
+  Ctx(ctx), ST(st), AP(ap) { }
 
 static MCSymbolRefExpr::VariantKind getVariantKind(unsigned MOFlags) {
   switch (MOFlags) {
   default: return MCSymbolRefExpr::VK_None;
   case SIInstrInfo::MO_GOTPCREL: return MCSymbolRefExpr::VK_GOTPCREL;
   }
 }
 
case MachineOperand::MO_Register:
       MCOp = MCOperand::createReg(AMDGPU::getMCReg(MO.getReg(), ST));
       break;
     case MachineOperand::MO_MachineBasicBlock:
       MCOp = MCOperand::createExpr(MCSymbolRefExpr::create(
                                    MO.getMBB()->getSymbol(), Ctx));
       break;
     case MachineOperand::MO_GlobalAddress: {
       const GlobalValue *GV = MO.getGlobal();
-      MCSymbol *Sym = Ctx.getOrCreateSymbol(StringRef(GV->getName()));
+      SmallString<128> SymbolName;
+      AP.getNameWithPrefix(SymbolName, GV);
+      MCSymbol *Sym = Ctx.getOrCreateSymbol(SymbolName);
       const MCExpr *SymExpr =
           MCSymbolRefExpr::create(Sym, getVariantKind(MO.getTargetFlags()),Ctx);
       const MCExpr *Expr = MCBinaryExpr::createAdd(SymExpr,
           MCConstantExpr::create(MO.getOffset(), Ctx), Ctx);
       MCOp = MCOperand::createExpr(Expr);
       break;
     }
     case MachineOperand::MO_ExternalSymbol: {
       MCSymbol *Sym = Ctx.getOrCreateSymbol(StringRef(MO.getSymbolName()));
       Sym->setExternal(true);
       const MCSymbolRefExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
       MCOp = MCOperand::createExpr(Expr);
       break;
     }
     }
     OutMI.addOperand(MCOp);
   }
 }
 
 void AMDGPUAsmPrinter::EmitInstruction(const MachineInstr *MI) {
   const AMDGPUSubtarget &STI = MF->getSubtarget<AMDGPUSubtarget>();
-  AMDGPUMCInstLower MCInstLowering(OutContext, STI);
+  AMDGPUMCInstLower MCInstLowering(OutContext, STI, *this);
 
   StringRef Err;
   if (!STI.getInstrInfo()->verifyInstruction(*MI, Err)) {
     LLVMContext &C = MI->getParent()->getParent()->getFunction()->getContext();
     C.emitError("Illegal instruction detected: " + Err);
     MI->dump();
   }
 

test/CodeGen/AMDGPU/anonymous-gv.ll

+; RUN: llc < %s -mtriple=amdgcn--amdhsa -mcpu=fiji | FileCheck %s
+
+; Make sure we don't crash on a global variable with no name.
+@0 = external addrspace(1) global i32
+
+; CHECK-LABEL: {{^}}test:
+; CHECK: s_endpgm
+define void @test() {
+  store i32 1, i32 addrspace(1)* @0
+  ret void
+}
+
+; CHECK-LABEL: .globl
+; CHECK: s_endpgm
+define void @1() {
+  ret void
+}