[PowerPC][XCOFF] Add support for zero initialized global values.

For XCOFF, globals mapped into the .bss section are linked as COMMON
definitions. This behaviour is incorrect for zero initialized data, so
emit those to the .data section instead.

Differential Revision: https://reviews.llvm.org/D69528

3 files changed, 115 insertions, 28 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 4978f4b9500..f941b98890c 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1855,6 +1855,12 @@ MCSection *TargetLoweringObjectFileXCOFF::SelectSectionForGlobal(
   if (Kind.isData())
     return DataSection;
 
+  // Zero initialized data must be emitted to the .data section because external
+  // linkage control sections that get mapped to the .bss section will be linked
+  // as tentative defintions, which is only appropriate for SectionKind::Common.
+  if (Kind.isBSS())
+    return DataSection;
+
   report_fatal_error("XCOFF other section types not yet implemented.");
 }
 
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 49365bcefa0..63dad686c7d 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -1747,7 +1747,7 @@ void PPCAIXAsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
     report_fatal_error("COMDAT not yet supported by AIX.");
 
   SectionKind GVKind = getObjFileLowering().getKindForGlobal(GV, TM);
-  if (!GVKind.isCommon() && !GVKind.isBSSLocal() && !GVKind.isData())
+  if (!GVKind.isCommon() && !GVKind.isBSS() && !GVKind.isData())
     report_fatal_error("Encountered a global variable kind that is "
                        "not supported yet.");
 
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-data.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-data.ll
index 5c8ac058715..c6a31ae8078 100644
--- a/llvm/test/CodeGen/PowerPC/aix-xcoff-data.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-data.ll
@@ -21,6 +21,9 @@
 @over_aligned = local_unnamed_addr global double 9.000000e+02, align 32
 @chrarray = local_unnamed_addr global [4 x i8] c"abcd", align 1
 @dblarr = local_unnamed_addr global [4 x double] [double 1.000000e+00, double 2.000000e+00, double 3.000000e+00, double 4.000000e+00], align 8
+@d_0 = global double 0.000000e+00, align 8
+@s_0 = global i16 0, align 2
+@f_0 = global float 0.000000e+00, align 4
 
 @a = common global i32 0, align 4
 @b = common global i64 0, align 8
@@ -84,6 +87,21 @@
 ; CHECK-NEXT: .llong  4613937818241073152
 ; CHECK-NEXT: .llong  4616189618054758400
 
+; CHECK:      .globl  d_0
+; CHECK-NEXT: .align 3
+; CHECK-NEXT: d_0:
+; CHECK-NEXT: .llong 0
+
+; CHECK:      .globl  s_0
+; CHECK-NEXT: .align  1
+; CHECK-NEXT: s_0:
+; CHECK-NEXT: .short 0
+
+; CHECK:      .globl f_0
+; CHECK-NEXT: .align 2
+; CHECK-NEXT: f_0:
+; CHECK-NEXT: .long 0
+
 ; CHECK-NEXT: .comm   a[RW],4,2
 ; CHECK-NEXT: .comm   b[RW],8,3
 ; CHECK-NEXT: .comm   c[RW],2,1
@@ -100,8 +118,8 @@
 ; OBJ-NEXT:   Magic: 0x1DF
 ; OBJ-NEXT:   NumberOfSections: 3
 ; OBJ-NEXT:   TimeStamp:
-; OBJ-NEXT:   SymbolTableOffset: 0xDC
-; OBJ-NEXT:   SymbolTableEntries: 34
+; OBJ-NEXT:   SymbolTableOffset: 0xEC
+; OBJ-NEXT:   SymbolTableEntries: 40
 ; OBJ-NEXT:   OptionalHeaderSize: 0x0
 ; OBJ-NEXT:   Flags: 0x0
 ; OBJ-NEXT: }
@@ -126,7 +144,7 @@
 ; OBJ-NEXT:     Name: .data
 ; OBJ-NEXT:     PhysicalAddress: 0x0
 ; OBJ-NEXT:     VirtualAddress: 0x0
-; OBJ-NEXT:     Size: 0x50
+; OBJ-NEXT:     Size: 0x60
 ; OBJ-NEXT:     RawDataOffset: 0x8C
 ; OBJ-NEXT:     RelocationPointer: 0x0
 ; OBJ-NEXT:     LineNumberPointer: 0x0
@@ -138,9 +156,9 @@
 ; OBJ:        Section {
 ; OBJ-NEXT:     Index: 3
 ; OBJ-NEXT:     Name: .bss
-; OBJ-NEXT:     PhysicalAddress: 0x50
-; OBJ-NEXT:     VirtualAddress: 0x50
-; OBJ-NEXT:     Size: 0x5C
+; OBJ-NEXT:     PhysicalAddress: 0x60
+; OBJ-NEXT:     VirtualAddress: 0x60
+; OBJ-NEXT:     Size: 0x6C
 ; OBJ-NEXT:     RawDataOffset: 0x0
 ; OBJ-NEXT:     RelocationPointer: 0x0
 ; OBJ-NEXT:     LineNumberPointer: 0x0
@@ -186,7 +204,7 @@
 ; SYMS-NEXT:     NumberOfAuxEntries: 1
 ; SYMS-NEXT:     CSECT Auxiliary Entry {
 ; SYMS-NEXT:       Index: [[#INDX+3]]
-; SYMS-NEXT:       SectionLen: 80
+; SYMS-NEXT:       SectionLen: 96
 ; SYMS-NEXT:       ParameterHashIndex: 0x0
 ; SYMS-NEXT:       TypeChkSectNum: 0x0
 ; SYMS-NEXT:       SymbolAlignmentLog2: 5
@@ -367,14 +385,77 @@
 
 ; SYMS:        Symbol {
 ; SYMS-NEXT:     Index: [[#INDX+20]]
-; SYMS-NEXT:     Name: a
+; SYMS-NEXT:     Name: d_0
 ; SYMS-NEXT:     Value (RelocatableAddress): 0x50
-; SYMS-NEXT:     Section: .bss
+; SYMS-NEXT:     Section: .data
 ; SYMS-NEXT:     Type: 0x0
 ; SYMS-NEXT:     StorageClass: C_EXT (0x2)
 ; SYMS-NEXT:     NumberOfAuxEntries: 1
 ; SYMS-NEXT:     CSECT Auxiliary Entry {
 ; SYMS-NEXT:       Index: [[#INDX+21]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: [[#INDX+2]]
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RW (0x5)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+22]]
+; SYMS-NEXT:     Name: s_0
+; SYMS-NEXT:     Value (RelocatableAddress): 0x58
+; SYMS-NEXT:     Section: .data
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+23]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: [[#INDX+2]]
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RW (0x5)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+24]]
+; SYMS-NEXT:     Name: f_0
+; SYMS-NEXT:     Value (RelocatableAddress): 0x5C
+; SYMS-NEXT:     Section: .data
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+25]]
+; SYMS-NEXT:       ContainingCsectSymbolIndex: [[#INDX+2]]
+; SYMS-NEXT:       ParameterHashIndex: 0x0
+; SYMS-NEXT:       TypeChkSectNum: 0x0
+; SYMS-NEXT:       SymbolAlignmentLog2: 0
+; SYMS-NEXT:       SymbolType: XTY_LD (0x2)
+; SYMS-NEXT:       StorageMappingClass: XMC_RW (0x5)
+; SYMS-NEXT:       StabInfoIndex: 0x0
+; SYMS-NEXT:       StabSectNum: 0x0
+; SYMS-NEXT:     }
+; SYMS-NEXT:   }
+
+; SYMS:        Symbol {
+; SYMS-NEXT:     Index: [[#INDX+26]]
+; SYMS-NEXT:     Name: a
+; SYMS-NEXT:     Value (RelocatableAddress): 0x60
+; SYMS-NEXT:     Section: .bss
+; SYMS-NEXT:     Type: 0x0
+; SYMS-NEXT:     StorageClass: C_EXT (0x2)
+; SYMS-NEXT:     NumberOfAuxEntries: 1
+; SYMS-NEXT:     CSECT Auxiliary Entry {
+; SYMS-NEXT:       Index: [[#INDX+27]]
 ; SYMS-NEXT:       SectionLen: 4
 ; SYMS-NEXT:       ParameterHashIndex: 0x0
 ; SYMS-NEXT:       TypeChkSectNum: 0x0
@@ -387,15 +468,15 @@
 ; SYMS-NEXT:   }
 
 ; SYMS:        Symbol {
-; SYMS-NEXT:     Index: [[#INDX+22]]
+; SYMS-NEXT:     Index: [[#INDX+28]]
 ; SYMS-NEXT:     Name: b
-; SYMS-NEXT:     Value (RelocatableAddress): 0x58
+; SYMS-NEXT:     Value (RelocatableAddress): 0x68
 ; SYMS-NEXT:     Section: .bss
 ; SYMS-NEXT:     Type: 0x0
 ; SYMS-NEXT:     StorageClass: C_EXT (0x2)
 ; SYMS-NEXT:     NumberOfAuxEntries: 1
 ; SYMS-NEXT:     CSECT Auxiliary Entry {
-; SYMS-NEXT:       Index: [[#INDX+23]]
+; SYMS-NEXT:       Index: [[#INDX+29]]
 ; SYMS-NEXT:       SectionLen: 8
 ; SYMS-NEXT:       ParameterHashIndex: 0x0
 ; SYMS-NEXT:       TypeChkSectNum: 0x0
@@ -408,15 +489,15 @@
 ; SYMS-NEXT:   }
 
 ; SYMS:        Symbol {
-; SYMS-NEXT:     Index: [[#INDX+24]]
+; SYMS-NEXT:     Index: [[#INDX+30]]
 ; SYMS-NEXT:     Name: c
-; SYMS-NEXT:     Value (RelocatableAddress): 0x60
+; SYMS-NEXT:     Value (RelocatableAddress): 0x70
 ; SYMS-NEXT:     Section: .bss
 ; SYMS-NEXT:     Type: 0x0
 ; SYMS-NEXT:     StorageClass: C_EXT (0x2)
 ; SYMS-NEXT:     NumberOfAuxEntries: 1
 ; SYMS-NEXT:     CSECT Auxiliary Entry {
-; SYMS-NEXT:       Index: [[#INDX+25]]
+; SYMS-NEXT:       Index: [[#INDX+31]]
 ; SYMS-NEXT:       SectionLen: 2
 ; SYMS-NEXT:       ParameterHashIndex: 0x0
 ; SYMS-NEXT:       TypeChkSectNum: 0x0
@@ -429,15 +510,15 @@
 ; SYMS-NEXT:   }
 
 ; SYMS:        Symbol {
-; SYMS-NEXT:     Index: [[#INDX+26]]
+; SYMS-NEXT:     Index: [[#INDX+32]]
 ; SYMS-NEXT:     Name: d
-; SYMS-NEXT:     Value (RelocatableAddress): 0x68
+; SYMS-NEXT:     Value (RelocatableAddress): 0x78
 ; SYMS-NEXT:     Section: .bss
 ; SYMS-NEXT:     Type: 0x0
 ; SYMS-NEXT:     StorageClass: C_EXT (0x2)
 ; SYMS-NEXT:     NumberOfAuxEntries: 1
 ; SYMS-NEXT:     CSECT Auxiliary Entry {
-; SYMS-NEXT:       Index: [[#INDX+27]]
+; SYMS-NEXT:       Index: [[#INDX+33]]
 ; SYMS-NEXT:       SectionLen: 8
 ; SYMS-NEXT:       ParameterHashIndex: 0x0
 ; SYMS-NEXT:       TypeChkSectNum: 0x0
@@ -450,15 +531,15 @@
 ; SYMS-NEXT:   }
 
 ; SYMS:        Symbol {
-; SYMS-NEXT:     Index: [[#INDX+28]]
+; SYMS-NEXT:     Index: [[#INDX+34]]
 ; SYMS-NEXT:     Name: f
-; SYMS-NEXT:     Value (RelocatableAddress): 0x70
+; SYMS-NEXT:     Value (RelocatableAddress): 0x80
 ; SYMS-NEXT:     Section: .bss
 ; SYMS-NEXT:     Type: 0x0
 ; SYMS-NEXT:     StorageClass: C_EXT (0x2)
 ; SYMS-NEXT:     NumberOfAuxEntries: 1
 ; SYMS-NEXT:     CSECT Auxiliary Entry {
-; SYMS-NEXT:       Index: [[#INDX+29]]
+; SYMS-NEXT:       Index: [[#INDX+35]]
 ; SYMS-NEXT:       SectionLen: 4
 ; SYMS-NEXT:       ParameterHashIndex: 0x0
 ; SYMS-NEXT:       TypeChkSectNum: 0x0
@@ -471,15 +552,15 @@
 ; SYMS-NEXT:   }
 
 ; SYMS:        Symbol {
-; SYMS-NEXT:     Index: [[#INDX+30]]
+; SYMS-NEXT:     Index: [[#INDX+36]]
 ; SYMS-NEXT:     Name: over_aligned_comm
-; SYMS-NEXT:     Value (RelocatableAddress): 0x80
+; SYMS-NEXT:     Value (RelocatableAddress): 0xA0
 ; SYMS-NEXT:     Section: .bss
 ; SYMS-NEXT:     Type: 0x0
 ; SYMS-NEXT:     StorageClass: C_EXT (0x2)
 ; SYMS-NEXT:     NumberOfAuxEntries: 1
 ; SYMS-NEXT:     CSECT Auxiliary Entry {
-; SYMS-NEXT:       Index: [[#INDX+31]]
+; SYMS-NEXT:       Index: [[#INDX+37]]
 ; SYMS-NEXT:       SectionLen: 8
 ; SYMS-NEXT:       ParameterHashIndex: 0x0
 ; SYMS-NEXT:       TypeChkSectNum: 0x0
@@ -492,15 +573,15 @@
 ; SYMS-NEXT:   }
 
 ; SYMS:        Symbol {
-; SYMS-NEXT:     Index: [[#INDX+32]]
+; SYMS-NEXT:     Index: [[#INDX+38]]
 ; SYMS-NEXT:     Name: array
-; SYMS-NEXT:     Value (RelocatableAddress): 0x88
+; SYMS-NEXT:     Value (RelocatableAddress): 0xA8
 ; SYMS-NEXT:     Section: .bss
 ; SYMS-NEXT:     Type: 0x0
 ; SYMS-NEXT:     StorageClass: C_EXT (0x2)
 ; SYMS-NEXT:     NumberOfAuxEntries: 1
 ; SYMS-NEXT:     CSECT Auxiliary Entry {
-; SYMS-NEXT:       Index: [[#INDX+33]]
+; SYMS-NEXT:       Index: [[#INDX+39]]
 ; SYMS-NEXT:       SectionLen: 33
 ; SYMS-NEXT:       ParameterHashIndex: 0x0
 ; SYMS-NEXT:       TypeChkSectNum: 0x0