[ARM GlobalISel] Support global variables for Thumb2

Add the same level of support as for ARM mode (i.e. still no TLS
support).

In most cases, it is sufficient to replace the opcodes with the
t2-equivalent, but there are some idiosyncrasies that I decided to
preserve because I don't understand the full implications:
* For ARM we use LDRi12 to load from constant pools, but for Thumb we
  use t2LDRpci (I'm not sure if the ideal would be to use t2LDRi12 for
  Thumb as well, or to use LDRcp for ARM).
* For Thumb we don't have an equivalent for MOV|LDRLIT_ga_pcrel_ldr, so
  we have to generate MOV|LDRLIT_ga_pcrel plus a load from GOT.

The tests are in separate files because they're hard enough to read even
without doubling the number of checks.

llvm-svn: 355077

8 files changed, 660 insertions, 26 deletions

diff --git a/llvm/test/CodeGen/ARM/GlobalISel/arm-legalize-globals.mir b/llvm/test/CodeGen/ARM/GlobalISel/arm-legalize-globals.mir
new file mode 100644
index 00000000000..52ac76886f6
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/GlobalISel/arm-legalize-globals.mir
@@ -0,0 +1,29 @@
+# RUN: llc -mtriple arm-- -run-pass=legalizer %s -o - | FileCheck %s
+# RUN: llc -mtriple thumb-- -mattr=+v6t2 -run-pass=legalizer %s -o - | FileCheck %s
+--- |
+  @a_global = global i32 42
+  define void @test_global_variable() { ret void }
+...
+---
+name:            test_global_variable
+# CHECK-LABEL: name: test_global_variable
+legalized:       false
+# CHECK: legalized: true
+regBankSelected: false
+selected:        false
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: _ }
+  - { id: 1, class: _ }
+body:             |
+  bb.0:
+    liveins: $r0
+
+    %0(s32) = COPY $r0
+    %1(p0) = G_GLOBAL_VALUE @a_global
+    ; G_GLOBAL_VALUE is legal, so we should find it unchanged in the output
+    ; CHECK: {{%[0-9]+}}:_(p0) = G_GLOBAL_VALUE @a_global
+    $r0 = COPY %1(p0)
+    BX_RET 14, $noreg, implicit $r0
+
+...
diff --git a/llvm/test/CodeGen/ARM/GlobalISel/arm-legalizer.mir b/llvm/test/CodeGen/ARM/GlobalISel/arm-legalizer.mir
index 1d77b7936bf..ae4e94904ec 100644
--- a/llvm/test/CodeGen/ARM/GlobalISel/arm-legalizer.mir
+++ b/llvm/test/CodeGen/ARM/GlobalISel/arm-legalizer.mir
@@ -6,9 +6,6 @@
 
   define void @test_phi_s64() #0 { ret void }
 
-  @a_global = global i32 42
-  define void @test_global_variable() { ret void }
-
   attributes #0 = { "target-features"="+vfp2" }
 ...
 ---
@@ -106,26 +103,3 @@ body:             |
     $d0 = COPY %4(s64)
     BX_RET 14, $noreg, implicit $d0
 ...
----
-name:            test_global_variable
-# CHECK-LABEL: name: test_global_variable
-legalized:       false
-# CHECK: legalized: true
-regBankSelected: false
-selected:        false
-tracksRegLiveness: true
-registers:
-  - { id: 0, class: _ }
-  - { id: 1, class: _ }
-body:             |
-  bb.0:
-    liveins: $r0
-
-    %0(s32) = COPY $r0
-    %1(p0) = G_GLOBAL_VALUE @a_global
-    ; G_GLOBAL_VALUE is legal, so we should find it unchanged in the output
-    ; CHECK: {{%[0-9]+}}:_(p0) = G_GLOBAL_VALUE @a_global
-    $r0 = COPY %1(p0)
-    BX_RET 14, $noreg, implicit $r0
-
-...
diff --git a/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-pic.ll b/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-pic.ll
new file mode 100644
index 00000000000..85058506824
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-pic.ll
@@ -0,0 +1,114 @@
+; RUN: llc -mtriple thumbv7-linux -relocation-model=pic -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,ELF
+; RUN: llc -mtriple thumbv7-linux -relocation-model=pic -mattr=+no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,ELF
+; RUN: llc -mtriple thumbv7-darwin -relocation-model=pic -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,DARWIN,DARWIN-MOVT
+; RUN: llc -mtriple thumbv7-darwin -relocation-model=pic -mattr=+no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,DARWIN,DARWIN-NOMOVT
+
+@internal_global = internal global i32 42
+define i32 @test_internal_global() {
+; CHECK-LABEL: test_internal_global:
+; ELF: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; ELF: [[ANCHOR:.L[[:alnum:]_]+]]:
+; DARWIN-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:L[[:alnum:]_]+]]
+; DARWIN-MOVT: movw r[[ADDR:[0-9]+]], :lower16:(_internal_global-([[ANCHOR:L[[:alnum:]_]+]]+4))
+; DARWIN-MOVT-NEXT: movt r[[ADDR]], :upper16:(_internal_global-([[ANCHOR]]+4))
+; DARWIN: [[ANCHOR:L[[:alnum:]_]+]]:
+; CHECK-NEXT: add r[[ADDR:[0-9]+]], pc
+; CHECK-NEXT: ldr r0, [r[[ADDR]]]
+; CHECK-NEXT: bx lr
+; ELF: [[LABEL]]:
+; ELF-NEXT: .long internal_global-([[ANCHOR]]+4)
+; DARWIN-NOMOVT: [[LABEL]]:
+; DARWIN-NOMOVT-NEXT: .long _internal_global-([[ANCHOR]]+4)
+; DARWIN-MOVT-NOT: .long _internal_global
+
+entry:
+  %v = load i32, i32* @internal_global
+  ret i32 %v
+}
+
+@external_global = external global i32
+define i32 @test_external_global() {
+; CHECK-LABEL: test_external_global:
+; ELF: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; ELF: [[ANCHOR:.L[[:alnum:]_]+]]:
+; DARWIN-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:L[[:alnum:]_]+]]
+; DARWIN-MOVT: movw r[[ADDR:[0-9]+]], :lower16:(L_external_global$non_lazy_ptr-([[ANCHOR:L[[:alnum:]_]+]]+4))
+; DARWIN-MOVT: movt r[[ADDR]], :upper16:(L_external_global$non_lazy_ptr-([[ANCHOR]]+4))
+; DARWIN: [[ANCHOR:L[[:alnum:]_]+]]:
+; CHECK-NEXT: add r[[ADDR:[0-9]+]], pc
+; CHECK-NEXT: ldr r[[ADDR:[0-9]+]], [r[[ADDR]]]
+; CHECK-NEXT: ldr r0, [r[[ADDR]]]
+; CHECK-NEXT: bx lr
+; ELF: [[LABEL]]:
+; ELF: [[TMPLABEL:.L[[:alnum:]_]+]]:
+; ELF: .long external_global(GOT_PREL)-(([[ANCHOR]]+4)-[[TMPLABEL]])
+; DARWIN-NOMOVT: [[LABEL]]:
+; DARWIN-NOMOVT: .long L_external_global$non_lazy_ptr-([[ANCHOR]]+4)
+; DARWIN-NOMOVT-NOT: .long L_external_global
+entry:
+  %v = load i32, i32* @external_global
+  ret i32 %v
+}
+
+@internal_constant = internal constant i32 42
+define i32 @test_internal_constant() {
+; CHECK-LABEL: test_internal_constant:
+; ELF: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; ELF: [[ANCHOR:.L[[:alnum:]_]+]]:
+; DARWIN-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:L[[:alnum:]_]+]]
+; DARWIN-MOVT: movw r[[ADDR:[0-9]+]], :lower16:(_internal_constant-([[ANCHOR:L[[:alnum:]_]+]]+4))
+; DARWIN-MOVT-NEXT: movt r[[ADDR]], :upper16:(_internal_constant-([[ANCHOR]]+4))
+; DARWIN: [[ANCHOR:L[[:alnum:]_]+]]:
+; CHECK-NEXT: add r[[ADDR:[0-9]+]], pc
+; CHECK-NEXT: ldr r0, [r[[ADDR]]]
+; CHECK-NEXT: bx lr
+; ELF: [[LABEL]]:
+; ELF-NEXT: .long internal_constant-([[ANCHOR]]+4)
+; DARWIN-NOMOVT: [[LABEL]]:
+; DARWIN-NOMOVT-NEXT: .long _internal_constant-([[ANCHOR]]+4)
+; DARWIN-MOVT-NOT: .long _internal_constant
+
+entry:
+  %v = load i32, i32* @internal_constant
+  ret i32 %v
+}
+
+@external_constant = external constant i32
+define i32 @test_external_constant() {
+; CHECK-LABEL: test_external_constant:
+; ELF: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; ELF: [[ANCHOR:.L[[:alnum:]_]+]]:
+; DARWIN-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:L[[:alnum:]_]+]]
+; DARWIN-MOVT: movw r[[ADDR:[0-9]+]], :lower16:(L_external_constant$non_lazy_ptr-([[ANCHOR:L[[:alnum:]_]+]]+4))
+; DARWIN-MOVT: movt r[[ADDR]], :upper16:(L_external_constant$non_lazy_ptr-([[ANCHOR]]+4))
+; DARWIN: [[ANCHOR:L[[:alnum:]_]+]]:
+; CHECK-NEXT: add r[[ADDR:[0-9]+]], pc
+; CHECK-NEXT: ldr r[[ADDR:[0-9]+]], [r[[ADDR]]]
+; CHECK-NEXT: ldr r0, [r[[ADDR]]]
+; CHECK-NEXT: bx lr
+; ELF: [[LABEL]]:
+; ELF: [[TMPLABEL:.L[[:alnum:]_]+]]:
+; ELF: .long external_constant(GOT_PREL)-(([[ANCHOR]]+4)-[[TMPLABEL]])
+; DARWIN-NOMOVT: [[LABEL]]:
+; DARWIN-NOMOVT: .long L_external_constant$non_lazy_ptr-([[ANCHOR]]+4)
+; DARWIN-NOMOVT-NOT: .long L_external_constant
+entry:
+  %v = load i32, i32* @external_constant
+  ret i32 %v
+}
+
+; ELF: internal_global:
+; DARWIN: _internal_global:
+; CHECK: .long 42
+; ELF: .size internal_global, 4
+
+; ELF: internal_constant:
+; DARWIN: _internal_constant:
+; CHECK: .long 42
+; ELF: .size internal_constant, 4
+
+; DARWIN-DAG: L_external_global$non_lazy_ptr:
+; DARWIN-DAG: .indirect_symbol _external_global
+
+; DARWIN-DAG: L_external_constant$non_lazy_ptr:
+; DARWIN-DAG: .indirect_symbol _external_constant
diff --git a/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-ropi-rwpi.ll b/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-ropi-rwpi.ll
new file mode 100644
index 00000000000..2fbdc2f9e61
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-ropi-rwpi.ll
@@ -0,0 +1,122 @@
+; RUN: llc -mtriple thumbv7-linux -relocation-model=ropi -mattr=-no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,RW-DEFAULT-MOVT,RW-DEFAULT,ROPI-MOVT,ROPI
+; RUN: llc -mtriple thumbv7-linux -relocation-model=ropi -mattr=+no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,RW-DEFAULT-NOMOVT,RW-DEFAULT,ROPI-NOMOVT,ROPI
+; RUN: llc -mtriple thumbv7-linux -relocation-model=rwpi -mattr=-no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,RO-DEFAULT-MOVT,RO-DEFAULT,RWPI-MOVT,RWPI
+; RUN: llc -mtriple thumbv7-linux -relocation-model=rwpi -mattr=+no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,RO-DEFAULT-NOMOVT,RO-DEFAULT,RWPI-NOMOVT,RWPI
+; RUN: llc -mtriple thumbv7-linux -relocation-model=ropi-rwpi -mattr=-no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,ROPI-MOVT,ROPI,RWPI-MOVT,RWPI
+; RUN: llc -mtriple thumbv7-linux -relocation-model=ropi-rwpi -mattr=+no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,ROPI-NOMOVT,ROPI,RWPI-NOMOVT,RWPI
+
+@internal_global = internal global i32 42
+define i32 @test_internal_global() {
+; CHECK-LABEL: test_internal_global:
+; RW-DEFAULT-MOVT: movw r[[ADDR:[0-9]+]], :lower16:internal_global
+; RW-DEFAULT-MOVT-NEXT: movt r[[ADDR]], :upper16:internal_global
+; RW-DEFAULT-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; RW-DEFAULT-NEXT: ldr r0, [r[[ADDR]]]
+; RW-DEFAULT-NEXT: bx lr
+; RW-DEFAULT-NOMOVT: [[LABEL]]:
+; RW-DEFAULT-NOMOVT-NEXT: .long internal_global
+
+; RWPI-MOVT: movw r[[ADDR:[0-9]+]], :lower16:internal_global(sbrel)
+; RWPI-MOVT-NEXT: movt r[[ADDR]], :upper16:internal_global(sbrel)
+; RWPI-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; RWPI-NEXT: add r[[ADDR:[0-9]+]], r9
+; RWPI-NEXT: ldr r0, [r[[ADDR]]]
+; RWPI-NEXT: bx lr
+; RWPI-NOMOVT: [[LABEL]]:
+; RWPI-NOMOVT-NEXT: .long internal_global(sbrel)
+entry:
+  %v = load i32, i32* @internal_global
+  ret i32 %v
+}
+
+@external_global = external global i32
+define i32 @test_external_global() {
+; CHECK-LABEL: test_external_global:
+; RW-DEFAULT-MOVT: movw r[[ADDR:[0-9]+]], :lower16:external_global
+; RW-DEFAULT-MOVT-NEXT: movt r[[ADDR]], :upper16:external_global
+; RW-DEFAULT-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; RW-DEFAULT-NEXT: ldr r0, [r[[ADDR]]]
+; RW-DEFAULT-NEXT: bx lr
+; RW-DEFAULT-NOMOVT: [[LABEL]]:
+; RW-DEFAULT-NOMOVT: .long external_global
+
+; RWPI-MOVT: movw r[[ADDR:[0-9]+]], :lower16:external_global(sbrel)
+; RWPI-MOVT-NEXT: movt r[[ADDR]], :upper16:external_global(sbrel)
+; RWPI-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; RWPI-NEXT: add r[[ADDR:[0-9]+]], r9
+; RWPI-NEXT: ldr r0, [r[[ADDR]]]
+; RWPI-NEXT: bx lr
+; RWPI-NOMOVT: [[LABEL]]:
+; RWPI-NOMOVT-NEXT: .long external_global(sbrel)
+entry:
+  %v = load i32, i32* @external_global
+  ret i32 %v
+}
+
+@internal_constant = internal constant i32 42
+define i32 @test_internal_constant() {
+; CHECK-LABEL: test_internal_constant:
+; ROPI-MOVT: movw r[[ADDR:[0-9]+]], :lower16:(internal_constant-([[ANCHOR:.L[[:alnum:]_]+]]+4)
+; ROPI-MOVT-NEXT: movt r[[ADDR]], :upper16:(internal_constant-([[ANCHOR]]+4)
+; ROPI-MOVT-NEXT: [[ANCHOR]]:
+; ROPI-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; ROPI-NOMOVT-NEXT: [[ANCHOR:.L[[:alnum:]_]+]]:
+; ROPI-NEXT: add r[[ADDR:[0-9]+]], pc
+; ROPI-NEXT: ldr r0, [r[[ADDR]]]
+; ROPI-NEXT: bx lr
+; ROPI-NOMOVT: [[LABEL]]:
+; ROPI-NOMOVT-NEXT: .long internal_constant-([[ANCHOR]]+4)
+
+; RO-DEFAULT-MOVT: movw r[[ADDR:[0-9]+]], :lower16:internal_constant
+; RO-DEFAULT-MOVT-NEXT: movt r[[ADDR]], :upper16:internal_constant
+; RO-DEFAULT-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; RO-DEFAULT-NEXT: ldr r0, [r[[ADDR]]]
+; RO-DEFAULT-NEXT: bx lr
+; RO-DEFAULT-NOMOVT: [[LABEL]]:
+; RO-DEFAULT-NOMOVT-NEXT: .long internal_constant
+entry:
+  %v = load i32, i32* @internal_constant
+  ret i32 %v
+}
+
+@external_constant = external constant i32
+define i32 @test_external_constant() {
+; CHECK-LABEL: test_external_constant:
+; ROPI-MOVT: movw r[[ADDR:[0-9]+]], :lower16:(external_constant-([[ANCHOR:.L[[:alnum:]_]+]]+4)
+; ROPI-MOVT-NEXT: movt r[[ADDR]], :upper16:(external_constant-([[ANCHOR]]+4)
+; ROPI-MOVT-NEXT: [[ANCHOR]]:
+; ROPI-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; ROPI-NOMOVT-NEXT: [[ANCHOR:.L[[:alnum:]_]+]]:
+; ROPI-NEXT: add r[[ADDR:[0-9]+]], pc
+; ROPI-NEXT: ldr r0, [r[[ADDR]]]
+; ROPI-NEXT: bx lr
+; ROPI-NOMOVT: [[LABEL]]:
+; ROPI-NOMOVT-NEXT: .long external_constant-([[ANCHOR]]+4)
+
+; RO-DEFAULT-MOVT: movw r[[ADDR:[0-9]+]], :lower16:external_constant
+; RO-DEFAULT-MOVT-NEXT: movt r[[ADDR]], :upper16:external_constant
+; RO-DEFAULT-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; RO-DEFAULT-NEXT: ldr r0, [r[[ADDR]]]
+; RO-DEFAULT-NEXT: bx lr
+; RO-DEFAULT-NOMOVT: [[LABEL]]:
+; RO-DEFAULT-NOMOVT: .long external_constant
+entry:
+  %v = load i32, i32* @external_constant
+  ret i32 %v
+}
+
+; RW-DEFAULT-NOMOVT: internal_global:
+; RW-DEFAULT-NOMOVT: .long 42
+; RW-DEFAULT-NOMOVT: .size internal_global, 4
+
+; RWPI-NOMOVT: internal_global:
+; RWPI-NOMOVT: .long 42
+; RWPI-NOMOVT: .size internal_global, 4
+
+; ROPI-NOMOVT: internal_constant:
+; ROPI-NOMOVT: .long 42
+; ROPI-NOMOVT: .size internal_constant, 4
+
+; RO-DEFAULT-NOMOVT: internal_constant:
+; RO-DEFAULT-NOMOVT: .long 42
+; RO-DEFAULT-NOMOVT: .size internal_constant, 4
diff --git a/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-static.ll b/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-static.ll
new file mode 100644
index 00000000000..53819b92acf
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/GlobalISel/thumb-isel-globals-static.ll
@@ -0,0 +1,50 @@
+; RUN: llc -mtriple thumbv7-linux -relocation-model=static -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,ELF,ELF-MOVT
+; RUN: llc -mtriple thumbv7-linux -relocation-model=static -mattr=+no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,ELF,ELF-NOMOVT
+; RUN: llc -mtriple thumbv7-darwin -relocation-model=static -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,DARWIN,DARWIN-MOVT
+; RUN: llc -mtriple thumbv7-darwin -relocation-model=static -mattr=+no-movt -global-isel %s -o - | FileCheck %s -check-prefixes=CHECK,DARWIN,DARWIN-NOMOVT
+
+@internal_global = internal global i32 42
+define i32 @test_internal_global() {
+; CHECK-LABEL: test_internal_global:
+; ELF-MOVT: movw r[[ADDR:[0-9]+]], :lower16:internal_global
+; ELF-MOVT-NEXT: movt r[[ADDR]], :upper16:internal_global
+; ELF-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:.L[[:alnum:]_]+]]
+; DARWIN-MOVT: movw r[[ADDR:[0-9]+]], :lower16:_internal_global
+; DARWIN-MOVT-NEXT: movt r[[ADDR]], :upper16:_internal_global
+; DARWIN-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:L[[:alnum:]_]+]]
+; CHECK-NEXT: ldr r0, [r[[ADDR]]]
+; CHECK-NEXT: bx lr
+; ELF-NOMOVT: [[LABEL]]:
+; ELF-NOMOVT-NEXT: .long internal_global
+; DARWIN-NOMOVT: [[LABEL]]:
+; DARWIN-NOMOVT-NEXT: .long _internal_global
+
+entry:
+  %v = load i32, i32* @internal_global
+  ret i32 %v
+}
+
+@external_global = external global i32
+define i32 @test_external_global() {
+; CHECK-LABEL: test_external_global:
+; ELF-MOVT: movw r[[ADDR:[0-9]+]], :lower16:external_global
+; ELF-MOVT-NEXT: movt r[[ADDR]], :upper16:external_global
+; ELF-NOMOVT: ldr r[[ADDR:[0-9]+]], [[CONST_POOL:.L[[:alnum:]_]+]]
+; DARWIN-MOVT: movw r[[ADDR:[0-9]+]], :lower16:_external_global
+; DARWIN-MOVT: movt r[[ADDR]], :upper16:_external_global
+; DARWIN-NOMOVT: ldr r[[ADDR:[0-9]+]], [[LABEL:L[[:alnum:]_]+]]
+; CHECK-NEXT: ldr r0, [r[[ADDR]]]
+; CHECK-NEXT: bx lr
+; ELF-NOMOVT: [[CONST_POOL]]:
+; ELF-NOMOVT: .long external_global
+; DARWIN-NOMOVT: [[LABEL]]:
+; DARWIN-NOMOVT: .long _external_global
+entry:
+  %v = load i32, i32* @external_global
+  ret i32 %v
+}
+
+; ELF: internal_global:
+; DARWIN: _internal_global:
+; CHECK: .long 42
+; ELF: .size internal_global, 4
diff --git a/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-pic.mir b/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-pic.mir
new file mode 100644
index 00000000000..ca76220bd06
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-pic.mir
@@ -0,0 +1,127 @@
+# RUN: llc -O0 -mtriple thumb-linux -relocation-model=pic -mattr=+v6t2,+no-movt -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,ELF
+# RUN: llc -O0 -mtriple thumb-linux-linux -relocation-model=pic -mattr=+v6t2,-no-movt -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,ELF
+# RUN: llc -O0 -mtriple thumb-linux-darwin -relocation-model=pic -mattr=+v6t2,+no-movt -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,DARWIN-NOMOVT
+# RUN: llc -O0 -mtriple thumb-linux-darwin -relocation-model=pic -mattr=+v6t2,-no-movt -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,DARWIN-MOVT
+--- |
+  @internal_global = internal global i32 42
+  define void @test_internal_global() { ret void }
+
+  @external_global = external global i32
+  define void @test_external_global() { ret void }
+
+  @internal_constant = internal constant i32 42
+  define void @test_internal_constant() { ret void }
+
+  @external_constant = external constant i32
+  define void @test_external_constant() { ret void }
+...
+---
+name:            test_internal_global
+# CHECK-LABEL: name: test_internal_global
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @internal_global
+    ; DARWIN-MOVT: [[G:%[0-9]+]]:rgpr = t2MOV_ga_pcrel target-flags(arm-nonlazy) @internal_global
+    ; DARWIN-NOMOVT: [[G:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel target-flags(arm-nonlazy) @internal_global
+    ; ELF: [[G:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel @internal_global
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @internal_global)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @internal_global)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
+---
+name:            test_external_global
+# CHECK-LABEL: name: test_external_global
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @external_global
+    ; DARWIN-MOVT: [[G_GOT:%[0-9]+]]:rgpr = t2MOV_ga_pcrel target-flags(arm-nonlazy) @external_global
+    ; DARWIN-MOVT: [[G:%[0-9]+]]:gpr = t2LDRi12 [[G_GOT]], 0, 14, $noreg :: (load 4 from got)
+    ; DARWIN-NOMOVT: [[G_GOT:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel target-flags(arm-nonlazy) @external_global
+    ; DARWIN-NOMOVT: [[G:%[0-9]+]]:gpr = t2LDRi12 [[G_GOT]], 0, 14, $noreg :: (load 4 from got)
+    ; ELF: [[G_GOT:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel target-flags(arm-got) @external_global
+    ; ELF: [[G:%[0-9]+]]:gpr = t2LDRi12 [[G_GOT]], 0, 14, $noreg :: (load 4 from got)
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @external_global)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @external_global)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
+---
+name:            test_internal_constant
+# CHECK-LABEL: name: test_internal_constant
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @internal_constant
+    ; DARWIN-MOVT: [[G:%[0-9]+]]:rgpr = t2MOV_ga_pcrel target-flags(arm-nonlazy) @internal_constant
+    ; DARWIN-NOMOVT: [[G:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel target-flags(arm-nonlazy) @internal_constant
+    ; ELF: [[G:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel @internal_constant
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @internal_constant)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @internal_constant)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
+---
+name:            test_external_constant
+# CHECK-LABEL: name: test_external_constant
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @external_constant
+    ; DARWIN-MOVT: [[G_GOT:%[0-9]+]]:rgpr = t2MOV_ga_pcrel target-flags(arm-nonlazy) @external_constant
+    ; DARWIN-MOVT: [[G:%[0-9]+]]:gpr = t2LDRi12 [[G_GOT]], 0, 14, $noreg :: (load 4 from got)
+    ; DARWIN-NOMOVT: [[G_GOT:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel target-flags(arm-nonlazy) @external_constant
+    ; DARWIN-NOMOVT: [[G:%[0-9]+]]:gpr = t2LDRi12 [[G_GOT]], 0, 14, $noreg :: (load 4 from got)
+    ; ELF: [[G_GOT:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel target-flags(arm-got) @external_constant
+    ; ELF: [[G:%[0-9]+]]:gpr = t2LDRi12 [[G_GOT]], 0, 14, $noreg :: (load 4 from got)
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @external_constant)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @external_constant)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
diff --git a/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-ropi-rwpi.mir b/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-ropi-rwpi.mir
new file mode 100644
index 00000000000..cbe99f93aa6
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-ropi-rwpi.mir
@@ -0,0 +1,147 @@
+# RUN: llc -O0 -mtriple thumb-linux -relocation-model=ropi -mattr=-no-movt,+v6t2 -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,RW-DEFAULT-MOVT,ROPI-MOVT
+# RUN: llc -O0 -mtriple thumb-linux -relocation-model=ropi -mattr=+no-movt,+v6t2 -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,RW-DEFAULT-NOMOVT,ROPI-NOMOVT
+# RUN: llc -O0 -mtriple thumb-linux -relocation-model=rwpi -mattr=-no-movt,+v6t2 -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,RWPI-MOVT,RWPI,RO-DEFAULT-MOVT
+# RUN: llc -O0 -mtriple thumb-linux -relocation-model=rwpi -mattr=+no-movt,+v6t2 -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,RWPI-NOMOVT,RWPI,RO-DEFAULT-NOMOVT
+# RUN: llc -O0 -mtriple thumb-linux -relocation-model=ropi-rwpi -mattr=-no-movt,+v6t2 -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,RWPI-MOVT,RWPI,ROPI-MOVT
+# RUN: llc -O0 -mtriple thumb-linux -relocation-model=ropi-rwpi -mattr=+no-movt,+v6t2 -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,RWPI-NOMOVT,RWPI,ROPI-NOMOVT
+--- |
+  @internal_global = internal global i32 42
+  define void @test_internal_global() { ret void }
+
+  @external_global = external global i32
+  define void @test_external_global() { ret void }
+
+  @internal_constant = internal constant i32 42
+  define void @test_internal_constant() { ret void }
+
+  @external_constant = external constant i32
+  define void @test_external_constant() { ret void }
+...
+---
+name:            test_internal_global
+# CHECK-LABEL: name: test_internal_global
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+# RW-DEFAULT-NOMOVT: constants:
+# RW-DEFAULT-NOMOVT: id: 0
+# RW-DEFAULT-NOMOVT: value: 'i32* @internal_global'
+# RWPI-NOMOVT: constants:
+# RWPI-NOMOVT: id: 0
+# RWPI-NOMOVT: value: 'internal_global(SBREL)'
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @internal_global
+    ; RW-DEFAULT-MOVT: [[G:%[0-9]+]]:rgpr = t2MOVi32imm @internal_global
+    ; RW-DEFAULT-NOMOVT: [[G:%[0-9]+]]:gpr = t2LDRpci %const.0, 14, $noreg :: (load 4 from constant-pool)
+    ; RWPI-MOVT: [[OFF:%[0-9]+]]:rgpr = t2MOVi32imm target-flags(arm-sbrel) @internal_global
+    ; RWPI-NOMOVT: [[OFF:%[0-9]+]]:rgpr = t2LDRpci %const.0, 14, $noreg :: (load 4 from constant-pool)
+    ; RWPI: [[G:%[0-9]+]]:gprnopc = t2ADDrr $r9, [[OFF]], 14, $noreg, $noreg
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @internal_global)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @internal_global)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
+---
+name:            test_external_global
+# CHECK-LABEL: name: test_external_global
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+# RW-DEFAULT-NOMOVT: constants:
+# RW-DEFAULT-NOMOVT: id: 0
+# RW-DEFAULT-NOMOVT: value: 'i32* @external_global'
+# RWPI-NOMOVT: constants:
+# RWPI-NOMOVT: id: 0
+# RWPI-NOMOVT: value: 'external_global(SBREL)'
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @external_global
+    ; RW-DEFAULT-MOVT: [[G:%[0-9]+]]:rgpr = t2MOVi32imm @external_global
+    ; RW-DEFAULT-NOMOVT: [[G:%[0-9]+]]:gpr = t2LDRpci %const.0, 14, $noreg :: (load 4 from constant-pool)
+    ; RWPI-MOVT: [[OFF:%[0-9]+]]:rgpr = t2MOVi32imm target-flags(arm-sbrel) @external_global
+    ; RWPI-NOMOVT: [[OFF:%[0-9]+]]:rgpr = t2LDRpci %const.0, 14, $noreg :: (load 4 from constant-pool)
+    ; RWPI: [[G:%[0-9]+]]:gprnopc = t2ADDrr $r9, [[OFF]], 14, $noreg, $noreg
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @external_global)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @external_global)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
+---
+name:            test_internal_constant
+# CHECK-LABEL: name: test_internal_constant
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+# RO-DEFAULT-NOMOVT: constants:
+# RO-DEFAULT-NOMOVT: id: 0
+# RO-DEFAULT-NOMOVT: value: 'i32* @internal_constant'
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @internal_constant
+    ; ROPI-MOVT: [[G:%[0-9]+]]:rgpr = t2MOV_ga_pcrel @internal_constant
+    ; ROPI-NOMOVT: [[G:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel @internal_constant
+    ; RO-DEFAULT-MOVT: [[G:%[0-9]+]]:rgpr = t2MOVi32imm @internal_constant
+    ; RO-DEFAULT-NOMOVT: [[G:%[0-9]+]]:gpr = t2LDRpci %const.0, 14, $noreg :: (load 4 from constant-pool)
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @internal_constant)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @internal_constant)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
+---
+name:            test_external_constant
+# CHECK-LABEL: name: test_external_constant
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+# RO-DEFAULT-NOMOVT: constants:
+# RO-DEFAULT-NOMOVT: id: 0
+# RO-DEFAULT-NOMOVT: value: 'i32* @external_constant'
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @external_constant
+    ; ROPI-MOVT: [[G:%[0-9]+]]:rgpr = t2MOV_ga_pcrel @external_constant
+    ; ROPI-NOMOVT: [[G:%[0-9]+]]:tgpr = tLDRLIT_ga_pcrel @external_constant
+    ; RO-DEFAULT-MOVT: [[G:%[0-9]+]]:rgpr = t2MOVi32imm @external_constant
+    ; RO-DEFAULT-NOMOVT: [[G:%[0-9]+]]:gpr = t2LDRpci %const.0, 14, $noreg :: (load 4 from constant-pool)
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @external_constant)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @external_constant)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
diff --git a/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-static.mir b/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-static.mir
new file mode 100644
index 00000000000..6e1e991fc7e
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/GlobalISel/thumb-select-globals-static.mir
@@ -0,0 +1,71 @@
+# RUN: llc -O0 -mtriple thumb-linux -mattr=+v6t2 -relocation-model=static -mattr=+no-movt -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,ELF-NOMOVT
+# RUN: llc -O0 -mtriple thumb-linux -mattr=+v6t2 -relocation-model=static -mattr=-no-movt,+v8m -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,ELF-MOVT
+# RUN: llc -O0 -mtriple thumb-darwin -mattr=+v6t2 -relocation-model=static -mattr=+no-movt -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,DARWIN-NOMOVT
+# RUN: llc -O0 -mtriple thumb-darwin -mattr=+v6t2 -relocation-model=static -mattr=-no-movt,+v8m -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=CHECK,DARWIN-MOVT
+--- |
+  @internal_global = internal global i32 42
+  define void @test_internal_global() { ret void }
+
+  @external_global = external global i32
+  define void @test_external_global() { ret void }
+...
+---
+name:            test_internal_global
+# CHECK-LABEL: name: test_internal_global
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+# ELF-NOMOVT: constants:
+# ELF-NOMOVT: id: 0
+# ELF-NOMOVT: value: 'i32* @internal_global'
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @internal_global
+    ; ELF-MOVT: [[G:%[0-9]+]]:rgpr = t2MOVi32imm @internal_global
+    ; ELF-NOMOVT: [[G:%[0-9]+]]:gpr = t2LDRpci %const.0, 14, $noreg :: (load 4 from constant-pool)
+    ; DARWIN-MOVT: [[G:%[0-9]+]]:rgpr = t2MOVi32imm @internal_global
+    ; DARWIN-NOMOVT: [[G:%[0-9]+]]:tgpr = tLDRLIT_ga_abs @internal_global
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @internal_global)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @internal_global)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...
+---
+name:            test_external_global
+# CHECK-LABEL: name: test_external_global
+legalized:       true
+regBankSelected: true
+selected:        false
+# CHECK: selected: true
+registers:
+  - { id: 0, class: gprb }
+  - { id: 1, class: gprb }
+# ELF-NOMOVT: constants:
+# ELF-NOMOVT: id: 0
+# ELF-NOMOVT: value: 'i32* @external_global'
+body:             |
+  bb.0:
+    %0(p0) = G_GLOBAL_VALUE @external_global
+    ; ELF-MOVT: [[G:%[0-9]+]]:rgpr = t2MOVi32imm @external_global
+    ; ELF-NOMOVT: [[G:%[0-9]+]]:gpr = t2LDRpci %const.0, 14, $noreg :: (load 4 from constant-pool)
+    ; DARWIN-MOVT: [[G:%[0-9]+]]:rgpr = t2MOVi32imm @external_global
+    ; DARWIN-NOMOVT: [[G:%[0-9]+]]:tgpr = tLDRLIT_ga_abs @external_global
+
+    %1(s32) = G_LOAD %0(p0) :: (load 4 from @external_global)
+    ; CHECK: [[V:%[0-9]+]]:gpr = t2LDRi12 [[G]], 0, 14, $noreg :: (load 4 from @external_global)
+
+    $r0 = COPY %1(s32)
+    ; CHECK: $r0 = COPY [[V]]
+
+    tBX_RET 14, $noreg, implicit $r0
+    ; CHECK: tBX_RET 14, $noreg, implicit $r0
+...