AMDGPU/R600: Fix fixups used for constant arrays

[arsenm]

Summary

Fixes bug 29289

[jvesely]

the test is better than D23964

[arsenm]

r279986

lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp

case AMDGPU::fixup_si_sopp_br: {
 
     return BrImm;
   }
   case FK_Data_1:
   case FK_Data_2:
   case FK_Data_4:
   case FK_Data_8:
   case FK_PCRel_4:
+  case FK_SecRel_4:
     return Value;
   default:
     llvm_unreachable("unhandled fixup kind");
   }
 }
 
 void AMDGPUAsmBackend::processFixupValue(const MCAssembler &Asm,
                                          const MCAsmLayout &Layout,

test/CodeGen/AMDGPU/r600-constant-array-fixup.ll

+; RUN: llc -filetype=obj -march=r600 -mcpu=cypress -verify-machineinstrs < %s | llvm-readobj -relocations -symbols | FileCheck %s
+
+@arr = internal unnamed_addr addrspace(2) constant [4 x i32] [i32 4, i32 5, i32 6, i32 7], align 4
+
+; CHECK: Relocations [
+; CHECK: Section (3) .rel.text {
+; CHECK: 0x58 R_AMDGPU_ABS32 .text 0x0
+; CHECK: }
+; CHECK: ]
+
+; CHECK: Symbol {
+; CHECK: Name: arr (11)
+; CHECK: Value: 0x70
+; CHECK: Size: 16
+; CHECK: Binding: Local (0x0)
+; CHECK: Type: Object (0x1)
+; CHECK: Other: 0
+; CHECK: Section: .text (0x2)
+; CHECK: }
+define amdgpu_kernel void @test_constant_array_fixup(i32 addrspace(1)* nocapture %out, i32 %idx) #0 {
+entry:
+  %arrayidx = getelementptr inbounds [4 x i32], [4 x i32] addrspace(2)* @arr, i32 0, i32 %idx
+  %val = load i32, i32 addrspace(2)* %arrayidx
+  store i32 %val, i32 addrspace(1)* %out, align 4
+  ret void
+}
+
+attributes #0 = { nounwind }
+