Clean up the conditional for handling of sign_extend_inreg based on

whether the extract instructions are available.

rdar://7956878

llvm-svn: 103277

2 files changed, 27 insertions, 2 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index f8c17b8ac2d..d8582ecf05f 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -393,8 +393,11 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
   setOperationAction(ISD::MEMBARRIER,         MVT::Other, Custom);
 
-  if (!Subtarget->hasV6Ops() && (!Subtarget->isThumb2()
-      || !Subtarget->hasT2ExtractPack())) {
+  // If the subtarget does not have extract instructions, sign_extend_inreg
+  // needs to be expanded. Extract is available in ARM mode on v6 and up,
+  // and on most Thumb2 implementations.
+  if ((!Subtarget->isThumb() && !Subtarget->hasV6Ops())
+      || (Subtarget->isThumb2() && !Subtarget->hasT2ExtractPack())) {
     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
   }
diff --git a/llvm/test/CodeGen/Thumb2/sign_extend_inreg.ll b/llvm/test/CodeGen/Thumb2/sign_extend_inreg.ll
new file mode 100644
index 00000000000..9a02c1caeb6
--- /dev/null
+++ b/llvm/test/CodeGen/Thumb2/sign_extend_inreg.ll
@@ -0,0 +1,22 @@
+; RUN: llc < %s -mcpu=cortex-a8 | FileCheck %s -check-prefix=CHECK-A8
+; RUN: llc < %s -mcpu=cortex-m3 | FileCheck %s -check-prefix=CHECK-M3
+
+target triple = "thumbv7-apple-darwin10"
+
+define arm_apcscc i32 @f1(i16* %ptr) nounwind {
+; CHECK-A8: f1
+; CHECK-A8: sxth
+; CHECK-M3: f1
+; CHECK-M3-NOT: sxth
+; CHECK-M3: bx lr
+  %1 = load i16* %ptr
+  %2 = icmp eq i16 %1, 1
+  %3 = sext i16 %1 to i32
+  br i1 %2, label %.next, label %.exit
+
+.next:
+  br label %.exit
+
+.exit:
+  ret i32 %3
+}