[AIX][XCOFF]Implement mergeable const

SUMMARY:
In this patch, we map mergeable const objects to the read-only section in the same manner as const objects that are not mergeable.

Reviewers: hubert.reinterpretcast,jasonliu
Subscribers: wuzish, nemanjai, hiraditya

Differential Revision: https://reviews.llvm.org/D71551

1 files changed, 166 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-mergeable-const.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-mergeable-const.ll
new file mode 100644
index 00000000000..09b1a4a3391
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-mergeable-const.ll
@@ -0,0 +1,166 @@
+; This file tests the codegen of mergeable const in AIX assembly.
+; This file also tests mergeable const in XCOFF object file generation.
+; RUN: llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc-ibm-aix-xcoff < %s | FileCheck %s
+; RUN: llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc64-ibm-aix-xcoff < %s | FileCheck %s
+; RUN: llc -verify-machineinstrs -mcpu=pwr4 -mtriple powerpc-ibm-aix-xcoff -filetype=obj -o %t.o < %s
+; RUN: llvm-objdump -D %t.o | FileCheck --check-prefix=CHECKOBJ %s
+; RUN: llvm-readobj -syms %t.o | FileCheck --check-prefix=CHECKSYM %s
+
+%struct.Merge_cnst32 = type { i64, i32, i64, i32 }
+%struct.Merge_cnst16 = type { i64, i32 }
+%struct.Merge_cnst8 = type { i32, i32 }
+%struct.Merge_cnst4 = type { i16, i8 }
+
+@__const.main.cnst32 = private unnamed_addr constant %struct.Merge_cnst32 { i64 4611686018427387954, i32 0, i64 0, i32 0 }
+@__const.main.cnst16 = private unnamed_addr constant %struct.Merge_cnst16 { i64 4611686018427387926, i32 0 }
+@__const.main.cnst8 = private unnamed_addr constant %struct.Merge_cnst8 { i32 1073741832, i32 0 }
+@__const.main.cnst4 = private unnamed_addr constant %struct.Merge_cnst4 { i16 16392, i8 0 }
+
+; Function Attrs: noinline nounwind optnone
+define i32 @main() #0 {
+entry:
+  ret i32 0
+}
+
+;CHECK:         .csect .rodata[RO]
+;CHECK-NEXT:         .align  4
+;CHECK-NEXT: .L__const.main.cnst32:
+;CHECK-NEXT:         .llong  4611686018427387954     # 0x4000000000000032
+;CHECK-NEXT:         .long   0                       # 0x0
+;CHECK-NEXT:         .space  4
+;CHECK-NEXT:         .llong  0                       # 0x0
+;CHECK-NEXT:         .long   0                       # 0x0
+;CHECK-NEXT:         .space  4
+;CHECK-NEXT:         .align  3
+;CHECK-NEXT: .L__const.main.cnst16:
+;CHECK-NEXT:         .llong  4611686018427387926     # 0x4000000000000016
+;CHECK-NEXT:         .long   0                       # 0x0
+;CHECK-NEXT:         .space  4
+;CHECK-NEXT:         .align  3
+;CHECK-NEXT: .L__const.main.cnst8:
+;CHECK-NEXT:         .long   1073741832              # 0x40000008
+;CHECK-NEXT:         .long   0                       # 0x0
+;CHECK-NEXT:         .align  3
+;CHECK-NEXT: .L__const.main.cnst4:
+;CHECK-NEXT:         .short  16392                   # 0x4008
+;CHECK-NEXT:         .byte   0                       # 0x0
+;CHECK-NEXT:         .space  1
+
+
+;CHECKOBJ:      00000000 .text:
+;CHECKOBJ-NEXT:        0: 38 60 00 00                    li 3, 0
+;CHECKOBJ-NEXT:        4: 4e 80 00 20                    blr
+;CHECKOBJ-NEXT:          ...{{[[:space:]] *}}
+;CHECKOBJ-NEXT: 00000010 .rodata:
+;CHECKOBJ-NEXT:        10: 40 00 00 00                    bdnzf   0, .+0
+;CHECKOBJ-NEXT:        14: 00 00 00 32                    <unknown>
+;CHECKOBJ-NEXT:          ...{{[[:space:]] *}}
+;CHECKOBJ-NEXT: 00000030 .L__const.main.cnst16:
+;CHECKOBJ-NEXT:       30: 40 00 00 00                    bdnzf   0, .+0
+;CHECKOBJ-NEXT:       34: 00 00 00 16                    <unknown>
+;CHECKOBJ-NEXT:          ...{{[[:space:]] *}}
+;CHECKOBJ-NEXT: 00000040 .L__const.main.cnst8:
+;CHECKOBJ-NEXT:       40: 40 00 00 08                    bdnzf   0, .+8
+;CHECKOBJ-NEXT:       44: 00 00 00 00                    <unknown>{{[[:space:]] *}}
+;CHECKOBJ-NEXT: 00000048 .L__const.main.cnst4:
+;CHECKOBJ-NEXT:       48: 40 08 00 00                    bdnzf   8, .+0
+
+
+;CHECKSYM:        Symbol {{[{][[:space:]] *}}Index: [[#Index:]]{{[[:space:]] *}}Name: .rodata
+;CHECKSYM-NEXT:     Value (RelocatableAddress): 0x10
+;CHECKSYM-NEXT:     Section: .text
+;CHECKSYM-NEXT:     Type: 0x0
+;CHECKSYM-NEXT:     StorageClass: C_HIDEXT (0x6B)
+;CHECKSYM-NEXT:     NumberOfAuxEntries: 1
+;CHECKSYM-NEXT:     CSECT Auxiliary Entry {
+;CHECKSYM-NEXT:       Index: [[#Index+1]]
+;CHECKSYM-NEXT:       SectionLen: 60
+;CHECKSYM-NEXT:       ParameterHashIndex: 0x0
+;CHECKSYM-NEXT:       TypeChkSectNum: 0x0
+;CHECKSYM-NEXT:       SymbolAlignmentLog2: 4
+;CHECKSYM-NEXT:       SymbolType: XTY_SD (0x1)
+;CHECKSYM-NEXT:       StorageMappingClass: XMC_RO (0x1)
+;CHECKSYM-NEXT:       StabInfoIndex: 0x0
+;CHECKSYM-NEXT:       StabSectNum: 0x0
+;CHECKSYM-NEXT:     }
+;CHECKSYM-NEXT:   }
+;CHECKSYM-NEXT:   Symbol {
+;CHECKSYM-NEXT:     Index: [[#Index+2]]
+;CHECKSYM-NEXT:     Name: .L__const.main.cnst32
+;CHECKSYM-NEXT:     Value (RelocatableAddress): 0x10
+;CHECKSYM-NEXT:     Section: .text
+;CHECKSYM-NEXT:     Type: 0x0
+;CHECKSYM-NEXT:     StorageClass: C_HIDEXT (0x6B)
+;CHECKSYM-NEXT:     NumberOfAuxEntries: 1
+;CHECKSYM-NEXT:     CSECT Auxiliary Entry {
+;CHECKSYM-NEXT:       Index: [[#Index+3]]
+;CHECKSYM-NEXT:       ContainingCsectSymbolIndex: [[#Index]]
+;CHECKSYM-NEXT:       ParameterHashIndex: 0x0
+;CHECKSYM-NEXT:       TypeChkSectNum: 0x0
+;CHECKSYM-NEXT:       SymbolAlignmentLog2: 0
+;CHECKSYM-NEXT:       SymbolType: XTY_LD (0x2)
+;CHECKSYM-NEXT:       StorageMappingClass: XMC_RO (0x1)
+;CHECKSYM-NEXT:       StabInfoIndex: 0x0
+;CHECKSYM-NEXT:       StabSectNum: 0x0
+;CHECKSYM-NEXT:     }
+;CHECKSYM-NEXT:   }
+;CHECKSYM-NEXT:   Symbol {
+;CHECKSYM-NEXT:     Index: [[#Index+4]]
+;CHECKSYM-NEXT:     Name: .L__const.main.cnst16
+;CHECKSYM-NEXT:     Value (RelocatableAddress): 0x30
+;CHECKSYM-NEXT:     Section: .text
+;CHECKSYM-NEXT:     Type: 0x0
+;CHECKSYM-NEXT:     StorageClass: C_HIDEXT (0x6B)
+;CHECKSYM-NEXT:     NumberOfAuxEntries: 1
+;CHECKSYM-NEXT:     CSECT Auxiliary Entry {
+;CHECKSYM-NEXT:       Index: [[#Index+5]]
+;CHECKSYM-NEXT:       ContainingCsectSymbolIndex: [[#Index]]
+;CHECKSYM-NEXT:       ParameterHashIndex: 0x0
+;CHECKSYM-NEXT:       TypeChkSectNum: 0x0
+;CHECKSYM-NEXT:       SymbolAlignmentLog2: 0
+;CHECKSYM-NEXT:       SymbolType: XTY_LD (0x2)
+;CHECKSYM-NEXT:       StorageMappingClass: XMC_RO (0x1)
+;CHECKSYM-NEXT:       StabInfoIndex: 0x0
+;CHECKSYM-NEXT:       StabSectNum: 0x0
+;CHECKSYM-NEXT:     }
+;CHECKSYM-NEXT:   }
+;CHECKSYM-NEXT:   Symbol {
+;CHECKSYM-NEXT:     Index: [[#Index+6]]
+;CHECKSYM-NEXT:     Name: .L__const.main.cnst8
+;CHECKSYM-NEXT:     Value (RelocatableAddress): 0x40
+;CHECKSYM-NEXT:     Section: .text
+;CHECKSYM-NEXT:     Type: 0x0
+;CHECKSYM-NEXT:     StorageClass: C_HIDEXT (0x6B)
+;CHECKSYM-NEXT:     NumberOfAuxEntries: 1
+;CHECKSYM-NEXT:     CSECT Auxiliary Entry {
+;CHECKSYM-NEXT:       Index: [[#Index+7]]
+;CHECKSYM-NEXT:       ContainingCsectSymbolIndex: [[#Index]]
+;CHECKSYM-NEXT:       ParameterHashIndex: 0x0
+;CHECKSYM-NEXT:       TypeChkSectNum: 0x0
+;CHECKSYM-NEXT:       SymbolAlignmentLog2: 0
+;CHECKSYM-NEXT:       SymbolType: XTY_LD (0x2)
+;CHECKSYM-NEXT:       StorageMappingClass: XMC_RO (0x1)
+;CHECKSYM-NEXT:       StabInfoIndex: 0x0
+;CHECKSYM-NEXT:       StabSectNum: 0x0
+;CHECKSYM-NEXT:     }
+;CHECKSYM-NEXT:   }
+;CHECKSYM-NEXT:   Symbol {
+;CHECKSYM-NEXT:     Index: [[#Index+8]]
+;CHECKSYM-NEXT:     Name: .L__const.main.cnst4
+;CHECKSYM-NEXT:     Value (RelocatableAddress): 0x48
+;CHECKSYM-NEXT:     Section: .text
+;CHECKSYM-NEXT:     Type: 0x0
+;CHECKSYM-NEXT:     StorageClass: C_HIDEXT (0x6B)
+;CHECKSYM-NEXT:     NumberOfAuxEntries: 1
+;CHECKSYM-NEXT:     CSECT Auxiliary Entry {
+;CHECKSYM-NEXT:       Index: [[#Index+9]]
+;CHECKSYM-NEXT:       ContainingCsectSymbolIndex: [[#Index]]
+;CHECKSYM-NEXT:       ParameterHashIndex: 0x0
+;CHECKSYM-NEXT:       TypeChkSectNum: 0x0
+;CHECKSYM-NEXT:       SymbolAlignmentLog2: 0
+;CHECKSYM-NEXT:       SymbolType: XTY_LD (0x2)
+;CHECKSYM-NEXT:       StorageMappingClass: XMC_RO (0x1)
+;CHECKSYM-NEXT:       StabInfoIndex: 0x0
+;CHECKSYM-NEXT:       StabSectNum: 0x0
+;CHECKSYM-NEXT:     }
+;CHECKSYM-NEXT:   }