//===----------------------------------------------------------------------===//
#include "ARMSubtarget.h"
+#include "ARMBaseInstrInfo.h"
#include "ARMBaseRegisterInfo.h"
-#include "llvm/GlobalValue.h"
-#include "llvm/Target/TargetSubtargetInfo.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/GlobalValue.h"
#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetOptions.h"
#define GET_SUBTARGETINFO_TARGET_DESC
#define GET_SUBTARGETINFO_CTOR
cl::desc("Reserve R9, making it unavailable as GPR"));
static cl::opt<bool>
-DarwinUseMOVT("arm-darwin-use-movt", cl::init(true), cl::Hidden);
+ArmUseMOVT("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"));
+UseFusedMulOps("arm-use-mulops",
+ cl::init(true), cl::Hidden);
+
+enum AlignMode {
+ DefaultAlign,
+ StrictAlign,
+ NoStrictAlign
+};
+
+static cl::opt<AlignMode>
+Align(cl::desc("Load/store alignment support"),
+ cl::Hidden, cl::init(DefaultAlign),
+ cl::values(
+ clEnumValN(DefaultAlign, "arm-default-align",
+ "Generate unaligned accesses only on hardware/OS "
+ "combinations that are known to support them"),
+ clEnumValN(StrictAlign, "arm-strict-align",
+ "Disallow all unaligned memory accesses"),
+ clEnumValN(NoStrictAlign, "arm-no-strict-align",
+ "Allow unaligned memory accesses"),
+ clEnumValEnd));
+
+enum ITMode {
+ DefaultIT,
+ RestrictedIT,
+ NoRestrictedIT
+};
+
+static cl::opt<ITMode>
+IT(cl::desc("IT block support"), cl::Hidden, cl::init(DefaultIT),
+ cl::ZeroOrMore,
+ cl::values(clEnumValN(DefaultIT, "arm-default-it",
+ "Generate IT block based on arch"),
+ clEnumValN(RestrictedIT, "arm-restrict-it",
+ "Disallow deprecated IT based on ARMv8"),
+ clEnumValN(NoRestrictedIT, "arm-no-restrict-it",
+ "Allow IT blocks based on ARMv7"),
+ clEnumValEnd));
ARMSubtarget::ARMSubtarget(const std::string &TT, const std::string &CPU,
- const std::string &FS)
+ const std::string &FS, const TargetOptions &Options)
: ARMGenSubtargetInfo(TT, CPU, FS)
, ARMProcFamily(Others)
- , HasV4TOps(false)
- , HasV5TOps(false)
- , HasV5TEOps(false)
- , HasV6Ops(false)
- , HasV6T2Ops(false)
- , HasV7Ops(false)
- , HasVFPv2(false)
- , HasVFPv3(false)
- , HasVFPv4(false)
- , HasNEON(false)
- , UseNEONForSinglePrecisionFP(false)
- , SlowFPVMLx(false)
- , HasVMLxForwarding(false)
- , SlowFPBrcc(false)
- , InThumbMode(false)
- , HasThumb2(false)
- , IsMClass(false)
- , NoARM(false)
- , PostRAScheduler(false)
- , IsR9Reserved(ReserveR9)
- , UseMovt(false)
- , SupportsTailCall(false)
- , HasFP16(false)
- , HasD16(false)
- , HasHardwareDivide(false)
- , HasT2ExtractPack(false)
- , HasDataBarrier(false)
- , Pref32BitThumb(false)
- , AvoidCPSRPartialUpdate(false)
- , HasRAS(false)
- , HasMPExtension(false)
- , FPOnlySP(false)
- , AllowsUnalignedMem(false)
- , Thumb2DSP(false)
+ , ARMProcClass(None)
, stackAlignment(4)
, CPUString(CPU)
, TargetTriple(TT)
- , TargetABI(ARM_ABI_APCS) {
- // Determine default and user specified characteristics
- if (CPUString.empty())
- CPUString = "generic";
+ , Options(Options)
+ , TargetABI(ARM_ABI_UNKNOWN) {
+ initializeEnvironment();
+ resetSubtargetFeatures(CPU, FS);
+}
+
+void ARMSubtarget::initializeEnvironment() {
+ HasV4TOps = false;
+ HasV5TOps = false;
+ HasV5TEOps = false;
+ HasV6Ops = false;
+ HasV6MOps = false;
+ HasV6T2Ops = false;
+ HasV7Ops = false;
+ HasV8Ops = false;
+ HasVFPv2 = false;
+ HasVFPv3 = false;
+ HasVFPv4 = false;
+ HasFPARMv8 = false;
+ HasNEON = false;
+ MinSize = false;
+ UseNEONForSinglePrecisionFP = false;
+ UseMulOps = UseFusedMulOps;
+ SlowFPVMLx = false;
+ HasVMLxForwarding = false;
+ SlowFPBrcc = false;
+ InThumbMode = false;
+ HasThumb2 = false;
+ NoARM = false;
+ PostRAScheduler = false;
+ IsR9Reserved = ReserveR9;
+ UseMovt = false;
+ SupportsTailCall = false;
+ HasFP16 = false;
+ HasD16 = false;
+ HasHardwareDivide = false;
+ HasHardwareDivideInARM = false;
+ HasT2ExtractPack = false;
+ HasDataBarrier = false;
+ Pref32BitThumb = false;
+ AvoidCPSRPartialUpdate = false;
+ AvoidMOVsShifterOperand = false;
+ HasRAS = false;
+ HasMPExtension = false;
+ HasVirtualization = false;
+ FPOnlySP = false;
+ HasPerfMon = false;
+ HasTrustZone = false;
+ HasCrypto = false;
+ HasCRC = false;
+ AllowsUnalignedMem = false;
+ Thumb2DSP = false;
+ UseNaClTrap = false;
+ UnsafeFPMath = false;
+}
+
+void ARMSubtarget::resetSubtargetFeatures(const MachineFunction *MF) {
+ AttributeSet FnAttrs = MF->getFunction()->getAttributes();
+ Attribute CPUAttr = FnAttrs.getAttribute(AttributeSet::FunctionIndex,
+ "target-cpu");
+ Attribute FSAttr = FnAttrs.getAttribute(AttributeSet::FunctionIndex,
+ "target-features");
+ std::string CPU =
+ !CPUAttr.hasAttribute(Attribute::None) ?CPUAttr.getValueAsString() : "";
+ std::string FS =
+ !FSAttr.hasAttribute(Attribute::None) ? FSAttr.getValueAsString() : "";
+ if (!FS.empty()) {
+ initializeEnvironment();
+ resetSubtargetFeatures(CPU, FS);
+ }
+
+ MinSize =
+ FnAttrs.hasAttribute(AttributeSet::FunctionIndex, Attribute::MinSize);
+}
+
+void ARMSubtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
+ if (CPUString.empty()) {
+ if (isTargetIOS() && TargetTriple.getArchName().endswith("v7s"))
+ // Default to the Swift CPU when targeting armv7s/thumbv7s.
+ CPUString = "swift";
+ else
+ CPUString = "generic";
+ }
// Insert the architecture feature derived from the target triple into the
// feature string. This is important for setting features that are implied
// based on the architecture version.
- std::string ArchFS = ARM_MC::ParseARMTriple(TT, CPUString);
+ std::string ArchFS = ARM_MC::ParseARMTriple(TargetTriple.getTriple(),
+ CPUString);
if (!FS.empty()) {
if (!ArchFS.empty())
- ArchFS = ArchFS + "," + FS;
+ ArchFS = ArchFS + "," + FS.str();
else
ArchFS = FS;
}
ParseSubtargetFeatures(CPUString, ArchFS);
- // Thumb2 implies at least V6T2. FIXME: Fix tests to explicitly specify a
- // ARM version or CPU and then remove this.
- if (!HasV6T2Ops && hasThumb2())
- HasV4TOps = HasV5TOps = HasV5TEOps = HasV6Ops = HasV6T2Ops = true;
+ // FIXME: This used enable V6T2 support implicitly for Thumb2 mode.
+ // Assert this for now to make the change obvious.
+ assert(hasV6T2Ops() || !hasThumb2());
+
+ // Keep a pointer to static instruction cost data for the specified CPU.
+ SchedModel = getSchedModelForCPU(CPUString);
// Initialize scheduling itinerary for the specified CPU.
InstrItins = getInstrItineraryForCPU(CPUString);
- // After parsing Itineraries, set ItinData.IssueWidth.
- computeIssueWidth();
-
- if (TT.find("eabi") != std::string::npos)
- // FIXME: We might want to separate AAPCS and EABI. Some systems, e.g.
- // Darwin-EABI conforms to AACPS but not the rest of EABI.
- TargetABI = ARM_ABI_AAPCS;
+ if (TargetABI == ARM_ABI_UNKNOWN) {
+ switch (TargetTriple.getEnvironment()) {
+ case Triple::Android:
+ case Triple::EABI:
+ case Triple::EABIHF:
+ case Triple::GNUEABI:
+ case Triple::GNUEABIHF:
+ case Triple::MachO:
+ TargetABI = ARM_ABI_AAPCS;
+ break;
+ default:
+ if (isTargetIOS() && isMClass())
+ TargetABI = ARM_ABI_AAPCS;
+ else
+ TargetABI = ARM_ABI_APCS;
+ break;
+ }
+ }
if (isAAPCS_ABI())
stackAlignment = 8;
- if (!isTargetIOS())
- UseMovt = hasV6T2Ops();
- else {
+ UseMovt = hasV6T2Ops() && ArmUseMOVT;
+
+ if (isTargetMachO()) {
IsR9Reserved = ReserveR9 | !HasV6Ops;
- UseMovt = DarwinUseMOVT && hasV6T2Ops();
- SupportsTailCall = !getTargetTriple().isOSVersionLT(5, 0);
- }
+ SupportsTailCall = !isTargetIOS() || !getTargetTriple().isOSVersionLT(5, 0);
+ } else
+ IsR9Reserved = ReserveR9;
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;
+ switch (Align) {
+ case DefaultAlign:
+ // Assume pre-ARMv6 doesn't support unaligned accesses.
+ //
+ // ARMv6 may or may not support unaligned accesses depending on the
+ // SCTLR.U bit, which is architecture-specific. We assume ARMv6
+ // Darwin targets support unaligned accesses, and others don't.
+ //
+ // ARMv7 always has SCTLR.U set to 1, but it has a new SCTLR.A bit
+ // which raises an alignment fault on unaligned accesses. Linux
+ // defaults this bit to 0 and handles it as a system-wide (not
+ // per-process) setting. It is therefore safe to assume that ARMv7+
+ // Linux targets support unaligned accesses. The same goes for NaCl.
+ //
+ // The above behavior is consistent with GCC.
+ AllowsUnalignedMem = (
+ (hasV7Ops() && (isTargetLinux() || isTargetNaCl())) ||
+ (hasV6Ops() && isTargetMachO()));
+ break;
+ case StrictAlign:
+ AllowsUnalignedMem = false;
+ break;
+ case NoStrictAlign:
+ AllowsUnalignedMem = true;
+ break;
+ }
+
+ switch (IT) {
+ case DefaultIT:
+ RestrictIT = hasV8Ops() ? true : false;
+ break;
+ case RestrictedIT:
+ RestrictIT = true;
+ break;
+ case NoRestrictedIT:
+ RestrictIT = false;
+ break;
+ }
+
+ // NEON f32 ops are non-IEEE 754 compliant. Darwin is ok with it by default.
+ uint64_t Bits = getFeatureBits();
+ if ((Bits & ARM::ProcA5 || Bits & ARM::ProcA8) && // Where this matters
+ (Options.UnsafeFPMath || isTargetDarwin()))
+ UseNEONForSinglePrecisionFP = true;
}
/// GVIsIndirectSymbol - true if the GV will be accessed via an indirect symbol.
if (GV->isDeclaration() && !GV->isMaterializable())
isDecl = true;
- if (!isTargetDarwin()) {
+ if (!isTargetMachO()) {
// Extra load is needed for all externally visible.
if (GV->hasLocalLinkage() || GV->hasHiddenVisibility())
return false;
}
unsigned ARMSubtarget::getMispredictionPenalty() const {
- // If we have a reasonable estimate of the pipeline depth, then we can
- // estimate the penalty of a misprediction based on that.
- if (isCortexA8())
- return 13;
- else if (isCortexA9())
- return 8;
-
- // Otherwise, just return a sensible default.
- return 10;
+ return SchedModel->MispredictPenalty;
}
-void ARMSubtarget::computeIssueWidth() {
- unsigned allStage1Units = 0;
- for (const InstrItinerary *itin = InstrItins.Itineraries;
- itin->FirstStage != ~0U; ++itin) {
- const InstrStage *IS = InstrItins.Stages + itin->FirstStage;
- allStage1Units |= IS->getUnits();
- }
- InstrItins.IssueWidth = 0;
- while (allStage1Units) {
- ++InstrItins.IssueWidth;
- // clear the lowest bit
- allStage1Units ^= allStage1Units & ~(allStage1Units - 1);
- }
- assert(InstrItins.IssueWidth <= 2 && "itinerary bug, too many stage 1 units");
+bool ARMSubtarget::hasSinCos() const {
+ return getTargetTriple().getOS() == Triple::IOS &&
+ !getTargetTriple().isOSVersionLT(7, 0);
}
bool ARMSubtarget::enablePostRAScheduler(
CodeGenOpt::Level OptLevel,
TargetSubtargetInfo::AntiDepBreakMode& Mode,
RegClassVector& CriticalPathRCs) const {
- Mode = TargetSubtargetInfo::ANTIDEP_CRITICAL;
- CriticalPathRCs.clear();
- CriticalPathRCs.push_back(&ARM::GPRRegClass);
+ Mode = TargetSubtargetInfo::ANTIDEP_NONE;
return PostRAScheduler && OptLevel >= CodeGenOpt::Default;
}