[BPF] Remove relocation for patchable externs

Previously, patchable extern relocations are introduced to patch
external variables used for multi versioning in
compile once, run everywhere use case. The load instruction
will be converted into a move with an patchable immediate
which can be changed by bpf loader on the host.

The kernel verifier has evolved and is able to load
and propagate constant values, so compiler relocation
becomes unnecessary. This patch removed codes related to this.

Differential Revision: https://reviews.llvm.org/D68760

llvm-svn: 374367

1 files changed, 0 insertions, 102 deletions

diff --git a/llvm/test/CodeGen/BPF/CORE/patchable-extern-uint.ll b/llvm/test/CodeGen/BPF/CORE/patchable-extern-uint.ll
deleted file mode 100644
index ba3770b4736..00000000000
--- a/llvm/test/CodeGen/BPF/CORE/patchable-extern-uint.ll
+++ /dev/null
@@ -1,102 +0,0 @@
-; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
-; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
-; Source code:
-;   extern __attribute__((section(".BPF.patchable_externs"))) unsigned a;
-;   int foo() { return a; }
-; Compilation flag:
-;   clang -target bpf -O2 -g -S -emit-llvm test.c
-
-@a = external dso_local local_unnamed_addr global i32, section ".BPF.patchable_externs", align 4
-
-; Function Attrs: norecurse nounwind readonly
-define dso_local i32 @foo() local_unnamed_addr #0 !dbg !7 {
-  %1 = load i32, i32* @a, align 4, !dbg !11, !tbaa !12
-; CHECK:             r0 = 0
-; CHECK-NEXT:        exit
-  ret i32 %1, !dbg !16
-}
-
-; CHECK:             .section        .BTF,"",@progbits
-; CHECK-NEXT:        .short  60319                   # 0xeb9f
-; CHECK-NEXT:        .byte   1
-; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   24
-; CHECK-NEXT:        .long   0
-; CHECK-NEXT:        .long   40
-; CHECK-NEXT:        .long   40
-; CHECK-NEXT:        .long   49
-; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
-; CHECK-NEXT:        .long   218103808               # 0xd000000
-; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
-; CHECK-NEXT:        .long   16777216                # 0x1000000
-; CHECK-NEXT:        .long   4
-; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
-; CHECK-NEXT:        .long   201326592               # 0xc000000
-; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=1
-; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
-; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
-; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .byte   97                      # string offset=15
-; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/tmp/yhs/work/tests/llvm/test.c" # string offset=17
-; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
-; CHECK-NEXT:        .short  60319                   # 0xeb9f
-; CHECK-NEXT:        .byte   1
-; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   40
-; CHECK-NEXT:        .long   0
-; CHECK-NEXT:        .long   20
-; CHECK-NEXT:        .long   20
-; CHECK-NEXT:        .long   28
-; CHECK-NEXT:        .long   48
-; CHECK-NEXT:        .long   0
-; CHECK-NEXT:        .long   48
-; CHECK-NEXT:        .long   20
-; CHECK-NEXT:        .long   8                       # FuncInfo
-; CHECK-NEXT:        .long   9                       # FuncInfo section string offset=9
-; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   .Lfunc_begin0
-; CHECK-NEXT:        .long   3
-; CHECK-NEXT:        .long   16                      # LineInfo
-; CHECK-NEXT:        .long   9                       # LineInfo section string offset=9
-; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   17
-; CHECK-NEXT:        .long   0
-; CHECK-NEXT:        .long   2061                    # Line 2 Col 13
-; CHECK-NEXT:        .long   8                       # ExternReloc
-; CHECK-NEXT:        .long   9                       # Extern reloc section string offset=9
-; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   15
-
-attributes #0 = { norecurse nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!3, !4, !5}
-!llvm.ident = !{!6}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.20181009 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
-!1 = !DIFile(filename: "test.c", directory: "/tmp/yhs/work/tests/llvm")
-!2 = !{}
-!3 = !{i32 2, !"Dwarf Version", i32 4}
-!4 = !{i32 2, !"Debug Info Version", i32 3}
-!5 = !{i32 1, !"wchar_size", i32 4}
-!6 = !{!"clang version 8.0.20181009 "}
-!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !8, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: true, unit: !0, retainedNodes: !2)
-!8 = !DISubroutineType(types: !9)
-!9 = !{!10}
-!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-!11 = !DILocation(line: 2, column: 20, scope: !7)
-!12 = !{!13, !13, i64 0}
-!13 = !{!"int", !14, i64 0}
-!14 = !{!"omnipotent char", !15, i64 0}
-!15 = !{!"Simple C/C++ TBAA"}
-!16 = !DILocation(line: 2, column: 13, scope: !7)