Index: llvm/test/Object/X86/yaml-elf-x86-rel-broken.yaml
===================================================================
--- llvm/test/Object/X86/yaml-elf-x86-rel-broken.yaml
+++ /dev/null
@@ -1,32 +0,0 @@
-# RUN: yaml2obj %s -o %t
-# RUN: obj2yaml %t | FileCheck %s
-
-# CHECK:       Relocations:
-# CHECK-NEXT:    - Offset:
-# CHECK-NEXT:      Symbol:
-# CHECK-NEXT:      Type: 0x000000FF
-
-!ELF
-FileHeader:
-  Class:           ELFCLASS32
-  Data:            ELFDATA2LSB
-  Type:            ET_REL
-  Machine:         EM_386
-Sections:
-  - Type:            SHT_PROGBITS
-    Name:            .text
-    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
-    AddressAlign:    0x04
-    Content:         0000000000000000
-  - Type:            SHT_REL
-    Name:            .rel.text
-    Link:            .symtab
-    Info:            .text
-    AddressAlign:    0x04
-    Relocations:
-      - Offset:          0
-        Symbol:          main
-        Type:            0xFF
-Symbols:
-  - Name:    main
-    Binding: STB_GLOBAL
Index: llvm/test/tools/obj2yaml/relocation-type.yaml
===================================================================
--- /dev/null
+++ llvm/test/tools/obj2yaml/relocation-type.yaml
@@ -0,0 +1,54 @@
+## Show how obj2yaml dumps relocation types.
+
+## Show that obj2yaml is able to dump relocation types when `e_machine` kind is unknown.
+
+# RUN: yaml2obj %s -o %t1 -DMACHINE=0x1234
+# RUN: obj2yaml %t1 | FileCheck %s -DMACHINE=0x1234 -DFIRST=0x00000000 -DSECOND=0x00000001
+
+# CHECK:      --- !ELF
+# CHECK-NEXT: FileHeader:
+# CHECK-NEXT:   Class:   ELFCLASS64
+# CHECK-NEXT:   Data:    ELFDATA2MSB
+# CHECK-NEXT:   Type:    ET_REL
+# CHECK-NEXT:   Machine: [[MACHINE]]
+# CHECK-NEXT: Sections:
+# CHECK-NEXT:   - Name:    .rela.text
+# CHECK-NEXT:     Type:    SHT_RELA
+# CHECK-NEXT:     EntSize: 0x0000000000000018
+# CHECK-NEXT:     Relocations:
+# CHECK-NEXT:       - Offset: 0x0000000000000009
+# CHECK-NEXT:         Type:   [[FIRST]]
+# CHECK-NEXT:       - Offset: 0x0000000000000008
+# CHECK-NEXT:         Type:   [[SECOND]]
+# CHECK-NEXT:       - Offset: 0x0000000000000007
+# CHECK-NEXT:         Type:   0x0000007F
+# CHECK-NEXT:       - Offset: 0x0000000000000006
+# CHECK-NEXT:         Type:   0x000000FF
+# CHECK-NEXT: ...
+
+## Show how obj2yaml dumps relocation types when `e_machine` kind is known.
+## In this case unknown relocation types are dumped as hex values.
+## All known relocation types are printed as strings representing relocation names.
+
+# RUN: yaml2obj %s -o %t2 -DMACHINE=EM_X86_64
+# RUN: obj2yaml %t2 | FileCheck %s -DMACHINE=EM_X86_64 -DFIRST=R_X86_64_NONE -DSECOND=R_X86_64_64
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2MSB
+  Type:    ET_REL
+  Machine: [[MACHINE]]
+Sections:
+  - Name: .rela.text
+    Type: SHT_RELA
+    Relocations:
+## Test a few noticable possible values: 0, 1, max(int8_t)=127, max(uint8_t)=0xFF=-1
+      - Offset: 0x9
+        Type:   0x0
+      - Offset: 0x8
+        Type:   0x1
+      - Offset: 0x7
+        Type:   0x7F
+      - Offset: 0x6
+        Type:   0xFF
Index: llvm/test/tools/obj2yaml/relocation-unsupported-machine.yaml
===================================================================
--- llvm/test/tools/obj2yaml/relocation-unsupported-machine.yaml
+++ /dev/null
@@ -1,35 +0,0 @@
-## Show that obj2yaml is able to dump relocations when `e_machine` is unknown.
-
-# RUN: yaml2obj %s -o %t1
-# RUN: obj2yaml %t1 | FileCheck %s
-
-# CHECK:      --- !ELF
-# CHECK-NEXT: FileHeader:
-# CHECK-NEXT:   Class:   ELFCLASS64
-# CHECK-NEXT:   Data:    ELFDATA2MSB
-# CHECK-NEXT:   Type:    ET_REL
-# CHECK-NEXT:   Machine: 0x1234
-# CHECK-NEXT: Sections:
-# CHECK-NEXT:   - Name:    .rela.text
-# CHECK-NEXT:     Type:    SHT_RELA
-# CHECK-NEXT:     EntSize: 0x0000000000000018
-# CHECK-NEXT:     Relocations:
-# CHECK-NEXT:       - Offset: 0x0000000000000001
-# CHECK-NEXT:         Type:   0x00000002
-# CHECK-NEXT:       - Offset: 0x0000000000000003
-# CHECK-NEXT:         Type:   0x00000004
-
---- !ELF
-FileHeader:
-  Class:   ELFCLASS64
-  Data:    ELFDATA2MSB
-  Type:    ET_REL
-  Machine: 0x1234
-Sections:
-  - Name: .rela.text
-    Type: SHT_RELA
-    Relocations:
-      - Offset: 0x1
-        Type:   0x2
-      - Offset: 0x3
-        Type:   0x4
Index: llvm/test/tools/yaml2obj/ELF/relocation-type.yaml
===================================================================
--- /dev/null
+++ llvm/test/tools/yaml2obj/ELF/relocation-type.yaml
@@ -0,0 +1,38 @@
+## Here we test that an arbitrary hex value can be used for a relocation type.
+
+## Show that yaml2obj is able to produce relocations for an unknown e_machine kind properly.
+
+# RUN: yaml2obj %s -o %t1 -DMACHINE=0x1234
+# RUN: llvm-readelf %t1 --relocations | FileCheck %s -DFIRST=Unknown -DSECOND=Unknown
+
+# CHECK: Relocation section '.rela.text' at offset 0x40 contains 4 entries:
+# CHECK:      Offset            Info             Type    Symbol's Value  Symbol's Name + Addend
+# CHECK-NEXT: 0000000000000009  0000000000000000 [[FIRST]]                               0
+# CHECK-NEXT: 0000000000000008  0000000000000001 [[SECOND]]                              0
+# CHECK-NEXT: 0000000000000007  000000000000007f Unknown                                 0
+# CHECK-NEXT: 0000000000000006  00000000000000ff Unknown                                 0
+
+## Show that yaml2obj is able to produce relocations for an arbitrary known e_machine kind properly.
+
+# RUN: yaml2obj %s -o %t2 -DMACHINE=EM_X86_64
+# RUN: llvm-readelf %t2 --relocations | FileCheck %s -DFIRST=R_X86_64_NONE -DSECOND=R_X86_64_64
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2MSB
+  Type:    ET_REL
+  Machine: [[MACHINE]]
+Sections:
+  - Name: .rela.text
+    Type: SHT_RELA
+    Relocations:
+## Test a few noticable possible values: 0, 1, max(int8_t)=127, max(uint8_t)=0xFF=-1
+      - Offset: 0x9
+        Type:   0x0
+      - Offset: 0x8
+        Type:   0x1
+      - Offset: 0x7
+        Type:   0x7F
+      - Offset: 0x6
+        Type:   0xFF
Index: llvm/test/tools/yaml2obj/ELF/relocation-unsupported-machine.yaml
===================================================================
--- llvm/test/tools/yaml2obj/ELF/relocation-unsupported-machine.yaml
+++ /dev/null
@@ -1,24 +0,0 @@
-## Show that yaml2obj is able to write relocations for an unknown e_machine properly.
-
-# RUN: yaml2obj %s -o %t1
-# RUN: llvm-readelf %t1 --relocations | FileCheck %s
-
-# CHECK: Relocation section '.rela.text' at offset 0x40 contains 2 entries:
-# CHECK:      Offset            Info             Type    Symbol's Value  Symbol's Name + Addend
-# CHECK-NEXT: 0000000000000001  0000000000000002 Unknown                                 0
-# CHECK-NEXT: 0000000000000003  0000000000000004 Unknown                                 0
-
---- !ELF
-FileHeader:
-  Class:   ELFCLASS64
-  Data:    ELFDATA2MSB
-  Type:    ET_REL
-  Machine: 0x1234
-Sections:
-  - Name: .rela.text
-    Type: SHT_RELA
-    Relocations:
-      - Offset: 0x1
-        Type:   0x2
-      - Offset: 0x3
-        Type:   0x4