}
bool ARMTargetLowering::allowsUnalignedMemoryAccesses(EVT VT) const {
- if (!Subtarget->hasV6Ops())
- // Pre-v6 does not support unaligned mem access.
- return false;
-
- // 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())
+ if (!Subtarget->allowsUnalignedMem())
return false;
switch (VT.getSimpleVT().SimpleTy) {
UseMOVT("arm-use-movt",
cl::init(true), cl::Hidden);
+static cl::opt<bool>
+StrictAlign("arm-strict-align", cl::Hidden,
+ cl::desc("Disallow all unaligned memory accesses"));
+
ARMSubtarget::ARMSubtarget(const std::string &TT, const std::string &FS,
bool isT)
: ARMArchVersion(V4)
, HasDataBarrier(false)
, Pref32BitThumb(false)
, FPOnlySP(false)
+ , AllowsUnalignedMem(false)
, stackAlignment(4)
, CPUString("generic")
, TargetType(isELF) // Default to ELF unless otherwise specified.
if (!isThumb() || hasThumb2())
PostRAScheduler = true;
+
+ // v6+ may or may not support unaligned mem access depending on the system
+ // configuration.
+ if (!StrictAlign && hasV6Ops() && isTargetDarwin())
+ AllowsUnalignedMem = true;
}
/// GVIsIndirectSymbol - true if the GV will be accessed via an indirect symbol.
/// precision.
bool FPOnlySP;
+ /// AllowsUnalignedMem - If true, the subtarget allows unaligned memory
+ /// accesses for some types. For details, see
+ /// ARMTargetLowering::allowsUnalignedMemoryAccesses().
+ bool AllowsUnalignedMem;
+
/// stackAlignment - The minimum alignment known to hold of the stack frame on
/// entry to the function and which must be maintained by every function.
unsigned stackAlignment;
bool useMovt() const { return UseMovt && hasV6T2Ops(); }
+ bool allowsUnalignedMem() const { return AllowsUnalignedMem; }
+
const std::string & getCPUString() const { return CPUString; }
/// enablePostRAScheduler - True at 'More' optimization.
; 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 -mtriple=armv6-apple-darwin -arm-strict-align | FileCheck %s -check-prefix=GENERIC
; RUN: llc < %s -mtriple=armv6-linux | FileCheck %s -check-prefix=GENERIC
; rdar://7113725