[AArch64][ELF] Support FDE references more than +/-2GB range for AArch64 large code model

[MaskRay]

Summary

For JIT applications, the code and .eh_frame maybe placed very far apart.
The large code model for AArch64 should handle FDE references more than +/-2GB range.

[MaskRay]

llvm/test/MC/ELF/cfi-large-model.s

8

-triple aarch64 is sufficient. This tests generic ELF behavior. Add -triple aarch64_be.

You can move aarch64 before x86_64 to be closer (oh,yes,x86_64->powerpc64le is an inversion pair) to an alphabetical order.

[wwei]

update test case

[wwei]

llvm/test/MC/ELF/cfi-large-model.s

8

using generic aarch64 and triple aarch64_be added. Here I keep the original reverse order so that it don't need to change the order of the large chunk of test code

[wwei]

ping

[MaskRay]

I realized I just ran into this issue:) I could not add a test for large code model because it does not use sdata8 yet: 3073a3aa1ef1ce8c9cac9b97a8e5905dd8779e16

[MaskRay]

Sorry, I think it is better dumping the output with llvm-dwarfdump --eh-frame, instead of inspecting the raw bytes.

[MaskRay]

Dupliate of D27629

llvm/lib/MC/MCObjectFileInfo.cpp

case Triple::mips64el:
     // since there is no R_MIPS_PC64 relocation (only a 32-bit version).
     if (PositionIndependent && !Large)
       FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
     else
       FDECFIEncoding = Ctx->getAsmInfo()->getCodePointerSize() == 4
                            ? dwarf::DW_EH_PE_sdata4
                            : dwarf::DW_EH_PE_sdata8;
     break;
+  case Triple::aarch64:
+  case Triple::aarch64_be:
   case Triple::ppc64:
   case Triple::ppc64le:
   case Triple::x86_64:
     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
                      (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
     break;
   case Triple::bpfel:
   case Triple::bpfeb:

llvm/test/MC/ELF/cfi-large-model.s

+// REQUIRES: aarch64-registered-target
 // REQUIRES: powerpc-registered-target
 // REQUIRES: x86-registered-target
 // RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu -large-code-model %s \
 // RUN:   -o - | llvm-readobj -S --sd | FileCheck --check-prefix=CHECK-X86 %s
 // RUN: llvm-mc -filetype=obj -triple powerpc64le-linux-gnu -large-code-model %s \
 // RUN:   -o - | llvm-readobj -S --sd | FileCheck --check-prefix=CHECK-PPC %s
-
+// RUN: llvm-mc -filetype=obj -triple aarch64-linux-gnu -large-code-model %s \
+// RUN:   -o - | llvm-readobj -S --sd | FileCheck --check-prefix=CHECK-ARM64 %s
 
 // CHECK-X86:      Section {
 // CHECK-X86:        Index:
 // CHECK-X86:        Name: .eh_frame
 // CHECK-X86-NEXT:   Type: SHT_X86_64_UNWIND
 // CHECK-X86-NEXT:   Flags [
 // CHECK-X86-NEXT:     SHF_ALLOC
 // CHECK-X86-NEXT:   ]

 // CHECK-PPC-NEXT:   EntrySize: 0
 // CHECK-PPC-NEXT:   SectionData (
 // CHECK-PPC-NEXT:     0000: 10000000 00000000 017A5200 04784101  |.........zR..xA.|
 // CHECK-PPC-NEXT:     0010: 1C0C0100 18000000 18000000 00000000  |................|
 // CHECK-PPC-NEXT:     0020: 00000000 00000000 00000000 00000000  |................|
 // CHECK-PPC-NEXT:   )
 // CHECK-PPC-NEXT: }
 
+// CHECK-ARM64: Section {
+// CHECK-ARM64:  Index:
+// CHECK-ARM64:  Name: .eh_frame
+// CHECK-ARM64-NEXT:   Type: SHT_PROGBITS
+// CHECK-ARM64-NEXT:   Flags [
+// CHECK-ARM64-NEXT:     SHF_ALLOC
+// CHECK-ARM64-NEXT:   ]
+// CHECK-ARM64-NEXT:   Address: 0x0
+// CHECK-ARM64-NEXT:   Offset: 0x40
+// CHECK-ARM64-NEXT:   Size: 48
+// CHECK-ARM64-NEXT:   Link: 0
+// CHECK-ARM64-NEXT:   Info: 0
+// CHECK-ARM64-NEXT:   AddressAlignment: 8
+// CHECK-ARM64-NEXT:   EntrySize: 0
+// CHECK-ARM64-NEXT:   SectionData (
+// CHECK-ARM64-NEXT:     0000: 10000000 00000000 017A5200 017C1E01  |.........zR..|..|
+// CHECK-ARM64-NEXT:     0010: 1C0C1F00 18000000 18000000 00000000  |................|
+// CHECK-ARM64-NEXT:     0020: 00000000 00000000 00000000 00000000  |................|
+// CHECK-ARM64-NEXT:   )
+// CHECK-ARM64-NEXT: }
+
 f:
     .cfi_startproc
     .cfi_endproc