Fix a gross typo: ARMv6+ may or may not support unaligned memory operations.

Even if they are suported by the core, they can be disabled
(this is just a configuration bit inside some register).

Allow unaligned memops on darwin and conservatively disallow them otherwise.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94889 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 59c198c..3e42be3 100644 (file)
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -3854,8 +3854,11 @@ bool ARMTargetLowering::allowsUnalignedMemoryAccesses(EVT VT) const {
   if (!Subtarget->hasV6Ops())
     // Pre-v6 does not support unaligned mem access.
     return false;
-  else if (!Subtarget->hasV6Ops()) {
-    // v6 may or may not support unaligned mem access.
+  else {
+    // v6+ may or may not support unaligned mem access depending on the system
+    // configuration.
+    // FIXME: This is pretty conservative. Should we provide cmdline option to
+    // control the behaviour?
     if (!Subtarget->isTargetDarwin())
       return false;
   }

diff --git a/test/CodeGen/ARM/unaligned_load_store.ll b/test/CodeGen/ARM/unaligned_load_store.ll
index fcaa2b3..a4494f3 100644 (file)
--- a/test/CodeGen/ARM/unaligned_load_store.ll
+++ b/test/CodeGen/ARM/unaligned_load_store.ll
@@ -1,6 +1,6 @@
 ; RUN: llc < %s -march=arm | FileCheck %s -check-prefix=GENERIC
 ; RUN: llc < %s -mtriple=armv6-apple-darwin | FileCheck %s -check-prefix=DARWIN_V6
-; RUN: llc < %s -march=arm -mattr=+v7a | FileCheck %s -check-prefix=V7
+; RUN: llc < %s -mtriple=armv6-linux | FileCheck %s -check-prefix=GENERIC
 
 ; rdar://7113725
 
@@ -20,9 +20,6 @@ entry:
 ; DARWIN_V6: ldr r1
 ; DARWIN_V6: str r1
 
-; V7: t:
-; V7: ldr r1
-; V7: str r1
   %__src1.i = bitcast i8* %b to i32*              ; <i32*> [#uses=1]
   %__dest2.i = bitcast i8* %a to i32*             ; <i32*> [#uses=1]
   %tmp.i = load i32* %__src1.i, align 1           ; <i32> [#uses=1]