[ARM] Define a subtarget feature that is used to avoid using movt/movw

pairs for 32-bit immediates.

This change is needed to avoid emitting movt/movw pairs when doing LTO
and do so on a per-function basis.

Out-of-tree projects currently using cl::opt option -arm-use-movt=0 or
false to avoid emitting movt/movw pairs should make changes to add
subtarget feature "+no-movt" (see the changes made to clang in r242368).

rdar://problem/21529937

Differential Revision: http://reviews.llvm.org/D11026

llvm-svn: 242369

2 files changed, 50 insertions, 5 deletions

diff --git a/llvm/test/CodeGen/ARM/fast-isel-mvn.ll b/llvm/test/CodeGen/ARM/fast-isel-mvn.ll
index 89b7c05158c..34bb7225854 100644
--- a/llvm/test/CodeGen/ARM/fast-isel-mvn.ll
+++ b/llvm/test/CodeGen/ARM/fast-isel-mvn.ll
@@ -1,8 +1,8 @@
-; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -arm-use-movt=false -mtriple=armv7-apple-ios     < %s | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
-; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -arm-use-movt=false -mtriple=armv7-linux-gnueabi < %s | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
-; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -arm-use-movt=false -mtriple=thumbv7-apple-ios   < %s | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
-; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -arm-use-movt=true  -mtriple=thumbv7-apple-ios   < %s | FileCheck %s --check-prefix=CHECK --check-prefix=THUMB
-; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -arm-use-movt=true  -mtriple=armv7-apple-ios     < %s | FileCheck %s --check-prefix=MOVT
+; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -mattr=+no-movt -mtriple=armv7-apple-ios     < %s | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
+; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -mattr=+no-movt -mtriple=armv7-linux-gnueabi < %s | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
+; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -mattr=+no-movt -mtriple=thumbv7-apple-ios   < %s | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
+; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -mtriple=thumbv7-apple-ios   < %s | FileCheck %s --check-prefix=CHECK --check-prefix=THUMB
+; RUN: llc -O0 -verify-machineinstrs -fast-isel-abort=1 -relocation-model=dynamic-no-pic -mtriple=armv7-apple-ios     < %s | FileCheck %s --check-prefix=MOVT
 ; rdar://10412592
 
 define void @t1() nounwind {
diff --git a/llvm/test/CodeGen/ARM/subtarget-no-movt.ll b/llvm/test/CodeGen/ARM/subtarget-no-movt.ll
new file mode 100644
index 00000000000..cb61bde3f9c
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/subtarget-no-movt.ll
@@ -0,0 +1,45 @@
+; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - | FileCheck -check-prefix=NO-OPTION %s
+; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -mattr=-no-movt | FileCheck -check-prefix=USE-MOVT %s
+; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -mattr=+no-movt | FileCheck -check-prefix=NO-USE-MOVT %s
+; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 | FileCheck -check-prefix=NO-OPTION %s
+; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 -mattr=-no-movt | FileCheck -check-prefix=USE-MOVT %s
+; RUN: llc -march thumb -mcpu=cortex-a8 -relocation-model=static %s -o - -O0 -mattr=+no-movt | FileCheck -check-prefix=NO-USE-MOVT %s
+
+; NO-OPTION-LABEL: {{_?}}foo0
+; NO-OPTION: ldr [[R0:r[0-9]+]], [[L0:.*]]
+; NO-OPTION: [[L0]]:
+; NO-OPTION: .long 2296237089
+
+; USE-MOVT-LABEL: {{_?}}foo0
+; USE-MOVT: movw [[R0:r[0-9]+]], #52257
+; USE-MOVT: movt [[R0]], #35037
+
+; NO-USE-MOVT-LABEL: {{_?}}foo0
+; NO-USE-MOVT: ldr [[R0:r[0-9]+]], [[L0:.*]]
+; NO-USE-MOVT: [[L0]]:
+; NO-USE-MOVT: .long 2296237089
+
+define i32 @foo0(i32 %a) #0 {
+  %1 = xor i32 -1998730207, %a
+  ret i32 %1
+}
+
+; NO-OPTION-LABEL: {{_?}}foo1
+; NO-OPTION: movw [[R0:r[0-9]+]], #52257
+; NO-OPTION: movt [[R0]], #35037
+
+; USE-MOVT-LABEL: {{_?}}foo1
+; USE-MOVT: movw [[R0:r[0-9]+]], #52257
+; USE-MOVT: movt [[R0]], #35037
+
+; NO-USE-MOVT-LABEL: {{_?}}foo1
+; NO-USE-MOVT: ldr [[R0:r[0-9]+]], [[L0:.*]]
+; NO-USE-MOVT: [[L0]]:
+; NO-USE-MOVT: .long 2296237089
+
+define i32 @foo1(i32 %a) {
+  %1 = xor i32 -1998730207, %a
+  ret i32 %1
+}
+
+attributes #0 = { "target-features"="+no-movt" }