diff --git a/llvm/docs/CommandGuide/llvm-objdump.rst b/llvm/docs/CommandGuide/llvm-objdump.rst
--- a/llvm/docs/CommandGuide/llvm-objdump.rst
+++ b/llvm/docs/CommandGuide/llvm-objdump.rst
@@ -28,7 +28,7 @@
 .. option:: -d, --disassemble
 
   Disassemble all executable sections found in the input files. On some
-  architectures (AArch64, x86), all known instructions are disassembled by
+  architectures (AArch64, PPC64, x86), all known instructions are disassembled by
   default. On the others, :option:`--mcpu` or :option:`--mattr` is needed to
   enable some instruction sets. Disabled instructions are displayed as
   ``<unknown>``.
diff --git a/llvm/lib/Object/ELFObjectFile.cpp b/llvm/lib/Object/ELFObjectFile.cpp
--- a/llvm/lib/Object/ELFObjectFile.cpp
+++ b/llvm/lib/Object/ELFObjectFile.cpp
@@ -358,6 +358,8 @@
   switch (getEMachine()) {
   case ELF::EM_AMDGPU:
     return getAMDGPUCPUName();
+  case ELF::EM_PPC64:
+    return StringRef("future");
   default:
     return None;
   }
diff --git a/llvm/test/MC/PowerPC/ppc64-prefix-align-labels.s b/llvm/test/MC/PowerPC/ppc64-prefix-align-labels.s
--- a/llvm/test/MC/PowerPC/ppc64-prefix-align-labels.s
+++ b/llvm/test/MC/PowerPC/ppc64-prefix-align-labels.s
@@ -38,11 +38,9 @@
 3:
 	blr
 # CHECK-BE:      3c:       60 00 00 00     nop
-# CHECK-BE-NEXT: 40:       06 01 ff ff
-# CHECK-BE-NEXT: 44:       38 22 ff f0
+# CHECK-BE-NEXT: 40:       06 01 ff ff 38 22 ff f0 paddi 1, 2, 8589934576, 0
 # CHECK-BE-NEXT: 48:       4e 80 00 20
 # CHECK-LE:      3c:       00 00 00 60     nop
-# CHECK-LE-NEXT: 40:       ff ff 01 06
-# CHECK-LE-NEXT: 44:       f0 ff 22 38
+# CHECK-LE-NEXT: 40:       ff ff 01 06 f0 ff 22 38 paddi 1, 2, 8589934576, 0
 # CHECK-LE-NEXT: 48:       20 00 80 4e
 
diff --git a/llvm/test/MC/PowerPC/ppc64-prefix-align.s b/llvm/test/MC/PowerPC/ppc64-prefix-align.s
--- a/llvm/test/MC/PowerPC/ppc64-prefix-align.s
+++ b/llvm/test/MC/PowerPC/ppc64-prefix-align.s
@@ -29,12 +29,10 @@
 # instruction can start at 40: which is 64 bytes aligned.
 # CHECK-BE:      38:	38 43 00 0f
 # CHECK-BE-NEXT: 3c:	60 00 00 00 	nop
-# CHECK-BE-NEXT: 40:	06 01 ff ff
-# CHECK-BE-NEXT: 44:	38 22 ff f0
+# CHECK-BE-NEXT: 40:	06 01 ff ff 38 22 ff f0  paddi 1, 2, 8589934576, 0
 # CHECK-LE:      38:	0f 00 43 38
 # CHECK-LE-NEXT: 3c:	00 00 00 60 	nop
-# CHECK-LE-NEXT: 40:	ff ff 01 06
-# CHECK-LE-NEXT: 44:	f0 ff 22 38
+# CHECK-LE-NEXT: 40:	ff ff 01 06 f0 ff 22 38  paddi 1, 2, 8589934576, 0
 paddi 1, 2, 8589934576, 0
 paddi 1, 2, 8589934576, 0
 paddi 1, 2, 8589934576, 0
@@ -54,13 +52,11 @@
 # CHECK-BE:      b8:	38 43 00 0f
 # CHECK-BE-NEXT: bc:	60 00 00 00 	nop
 # CHECK-BE:      <LAB1>:
-# CHECK-BE-NEXT: c0:	06 01 ff ff
-# CHECK-BE-NEXT: c4:	38 22 ff f0
+# CHECK-BE-NEXT: c0:	06 01 ff ff 38 22 ff f0  paddi 1, 2, 8589934576, 0
 # CHECK-LE:      b8:	0f 00 43 38
 # CHECK-LE-NEXT: bc:	00 00 00 60 	nop
 # CHECK-LE:      <LAB1>:
-# CHECK-LE-NEXT: c0:	ff ff 01 06
-# CHECK-LE-NEXT: c4:	f0 ff 22 38
+# CHECK-LE-NEXT: c0:	ff ff 01 06 f0 ff 22 38  paddi 1, 2, 8589934576, 0
 LAB1: paddi 1, 2, 8589934576, 0
 paddi 1, 2, 8589934576, 0
 paddi 1, 2, 8589934576, 0
@@ -72,13 +68,11 @@
 # CHECK-BE:      f8:	38 43 00 0f
 # CHECK-BE:      <LAB2>:
 # CHECK-BE-NEXT: fc:	60 00 00 00 	nop
-# CHECK-BE-NEXT: 100:	06 01 ff ff
-# CHECK-BE-NEXT: 104:	38 22 ff f0
+# CHECK-BE-NEXT: 100:	06 01 ff ff 38 22 ff f0  paddi 1, 2, 8589934576, 0
 # CHECK-LE:      f8:	0f 00 43 38
 # CHECK-LE:      <LAB2>:
 # CHECK-LE-NEXT: fc:	00 00 00 60 	nop
-# CHECK-LE-NEXT: 100:	ff ff 01 06
-# CHECK-LE-NEXT: 104:	f0 ff 22 38
+# CHECK-LE-NEXT: 100:	ff ff 01 06 f0 ff 22 38  paddi 1, 2, 8589934576, 0
 LAB2:
   paddi 1, 2, 8589934576, 0
 
diff --git a/llvm/test/tools/llvm-objdump/ELF/PowerPC/mcpu.s b/llvm/test/tools/llvm-objdump/ELF/PowerPC/mcpu.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-objdump/ELF/PowerPC/mcpu.s
@@ -0,0 +1,15 @@
+## Test that we default to --mcpu=future and disassemble all known instructions.
+## The default is different from producers (e.g. Clang).
+# RUN: llvm-mc -triple=powerpc64le -filetype=obj %s -o %t
+# RUN: llvm-objdump -d --no-show-raw-insn %t | FileCheck %s --check-prefixes=CHECK,FUTURE
+# RUN: llvm-objdump -d --no-show-raw-insn --mcpu=future %t | FileCheck %s --check-prefixes=CHECK,FUTURE
+# RUN: llvm-objdump -d --no-show-raw-insn --mcpu=pwr9 %t | FileCheck %s --check-prefixes=CHECK,UNKNOWN
+
+# CHECK-LABEL: <_start>:
+# FUTURE-NEXT:   pld 3, 0(0), 1
+# UNKNOWN-COUNT-2: <unknown>
+# CHECK-EMPTY:
+
+.globl _start
+_start:
+  pld 3, 0(0), 1