[llvm] r206211 - [ARM64][MC] Set the default CPU to cyclone when initilizating the MC layer.

[Eric Christopher]

Let's go with the "generic" x86 model. It looks like ARM64 does have a
definition for that.

-eric

On Mon, Apr 14, 2014 at 3:13 PM, Quentin Colombet <qcolombet at apple.com> wrote:
> Well, in fact, I am not sure what is the best approach here.
>
> ARM and X86 already seem to duplicate this logic somehow, see below.
>
> So if we are about to duplicate something I’d prefer to keep it minimal like
> in the current patch.
>
> What do you think?
>
> ** X86 **
>
> — X86Subtarget.cpp:
> void X86Subtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
>   std::string CPUName = CPU;
>   if (CPUName.empty())
>     CPUName = "generic";
>
> — X86MCTargetDesc.cpp:
> MCSubtargetInfo *X86_MC::createX86MCSubtargetInfo(StringRef TT, StringRef
> CPU,
>                                                   StringRef FS) {
> […]
>   std::string CPUName = CPU;
>   if (CPUName.empty()) {
> #if defined(i386) || defined(__i386__) || defined(__x86__) ||
> defined(_M_IX86)\
>     || defined(__x86_64__) || defined(_M_AMD64) || defined (_M_X64)
>     CPUName = sys::getHostCPUName();
> #else
>     CPUName = "generic";
> #endif
>   }
>
>
> ** ARM **
>
> — ARMSubtarget.cpp:
> 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";
>   }
>
> — ARMMCTargetDesc.cpp:
> std::string ARM_MC::ParseARMTriple(StringRef TT, StringRef CPU) {
> [...]
>   bool NoCPU = CPU == "generic" || CPU.empty();
>   std::string ARMArchFeature;
>   if (Idx) {
>     unsigned SubVer = TT[Idx];
>     if (SubVer == '8') {
>       if (NoCPU)
>         // v8a: FeatureDB, FeatureFPARMv8, FeatureNEON, FeatureDSPThumb2,
>         //      FeatureMP, FeatureHWDiv, FeatureHWDivARM, FeatureTrustZone,
>         //      FeatureT2XtPk, FeatureCrypto, FeatureCRC
>         ARMArchFeature =
> "+v8,+db,+fp-armv8,+neon,+t2dsp,+mp,+hwdiv,+hwdiv-arm,"
>                          "+trustzone,+t2xtpk,+crypto,+crc";
>       else
>         // Use CPU to figure out the exact features
>         ARMArchFeature = "+v8”;
> […]
>
> -Quentin
>
> On Apr 14, 2014, at 3:02 PM, Eric Christopher <echristo at gmail.com> wrote:
>
> Thanks!
>
> I'd probably see the ARM one as closer... it doesn't cope well if
> there's no cpu given it doesn't look like :)
>
> -eric
>
> On Mon, Apr 14, 2014 at 3:00 PM, Quentin Colombet <qcolombet at apple.com>
> wrote:
>
> Sorry, I thought I was doing the same thing as X86 here.
> I’ve been misled by this sequence:
> MCSubtargetInfo *X86_MC::createX86MCSubtargetInfo(StringRef TT, StringRef
> CPU,
>                                                  StringRef FS) {
> [...]
>  std::string CPUName = CPU;
>  if (CPUName.empty()) {
> #if defined(i386) || defined(__i386__) || defined(__x86__) ||
> defined(_M_IX86)\
>    || defined(__x86_64__) || defined(_M_AMD64) || defined (_M_X64)
>    CPUName = sys::getHostCPUName();
> #else
>    CPUName = "generic";
> #endif
>  }
>
> Let me rework my copy then!
>
> -Quentin
>
> On Apr 14, 2014, at 2:42 PM, Eric Christopher <echristo at gmail.com> wrote:
>
> Uh, what?
>
> How about taking the same code from the ARM or X86 backends? Or something
> else?
>
> -eric
>
> On Mon, Apr 14, 2014 at 2:25 PM, Quentin Colombet <qcolombet at apple.com>
> wrote:
>
> Author: qcolombet
> Date: Mon Apr 14 16:25:53 2014
> New Revision: 206211
>
> URL: http://llvm.org/viewvc/llvm-project?rev=206211&view=rev
> Log:
> [ARM64][MC] Set the default CPU to cyclone when initilizating the MC layer.
> This matches that ARM64Subtarget does for now.
>
> This is related to <rdar://problem/16573920>
>
> Modified:
>   llvm/trunk/lib/Target/ARM64/MCTargetDesc/ARM64MCTargetDesc.cpp
>
> Modified: llvm/trunk/lib/Target/ARM64/MCTargetDesc/ARM64MCTargetDesc.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM64/MCTargetDesc/ARM64MCTargetDesc.cpp?rev=206211&r1=206210&r2=206211&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM64/MCTargetDesc/ARM64MCTargetDesc.cpp
> (original)
> +++ llvm/trunk/lib/Target/ARM64/MCTargetDesc/ARM64MCTargetDesc.cpp Mon Apr
> 14 16:25:53 2014
> @@ -43,6 +43,12 @@ static MCInstrInfo *createARM64MCInstrIn
> static MCSubtargetInfo *createARM64MCSubtargetInfo(StringRef TT, StringRef
> CPU,
>                                                   StringRef FS) {
>  MCSubtargetInfo *X = new MCSubtargetInfo();
> +
> +  // FIXME: Make this darwin-only.
> +  if (CPU.empty())
> +    // We default to Cyclone for now, on Darwin.
> +    CPU = "cyclone";
> +
>  InitARM64MCSubtargetInfo(X, TT, CPU, FS);
>  return X;
> }
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
>
>