[PowerPC] Refactor popcnt[dw] target features

Instead of using two feature bits, one to indicate the availability of the
popcnt[dw] instructions, and another to indicate whether or not they're fast,
use a single enum. This allows more consistent control via target attribute
strings, and via Clang's command line.

llvm-svn: 264690

lib/Target/PowerPC/PPC.td

@@ -86,8 +86,6 @@ def FeatureFPCVT     : SubtargetFeature<"fpcvt", "HasFPCVT", "true",
   "Enable fc[ft]* (unsigned and single-precision) and lfiwzx instructions">;
 def FeatureISEL      : SubtargetFeature<"isel","HasISEL", "true",
                                         "Enable the isel instruction">;
-def FeaturePOPCNTD   : SubtargetFeature<"popcntd","HasPOPCNTD", "true",
-                                        "Enable the popcnt[dw] instructions">;
 def FeatureBPERMD    : SubtargetFeature<"bpermd", "HasBPERMD", "true",
                                         "Enable the bpermd instruction">;
 def FeatureExtDiv    : SubtargetFeature<"extdiv", "HasExtDiv", "true",
@@ -152,14 +150,18 @@ def FeatureFloat128 :
                    "Enable the __float128 data type for IEEE-754R Binary128.",
                    [FeatureVSX]>;
 
-def DeprecatedDST    : SubtargetFeature<"", "DeprecatedDST", "true",
-  "Treat vector data stream cache control instructions as deprecated">;
-
+def FeaturePOPCNTD   : SubtargetFeature<"popcntd","HasPOPCNTD",
+                                        "POPCNTD_Fast",
+                                        "Enable the popcnt[dw] instructions">;
 // Note that for the a2/a2q processor models we should not use popcnt[dw] by
 // default. These processors do support the instructions, but they're
 // microcoded, and the software emulation is about twice as fast.
-def SlowPOPCNTD      : SubtargetFeature<"slow-popcntd","SlowPOPCNTD", "true",
-                                        "The popcnt[dw] instructions are slow">;
+def FeatureSlowPOPCNTD : SubtargetFeature<"slow-popcntd","HasPOPCNTD",
+                                          "POPCNTD_Slow",
+                                          "Has slow popcnt[dw] instructions">;
+
+def DeprecatedDST    : SubtargetFeature<"", "DeprecatedDST", "true",
+  "Treat vector data stream cache control instructions as deprecated">;
 
 /*  Since new processors generally contain a superset of features of those that
     came before them, the idea is to make implementations of new processors
@@ -343,7 +345,7 @@ def : ProcessorModel<"a2", PPCA2Model,
                    FeatureFRSQRTE, FeatureFRSQRTES, FeatureRecipPrec,
                    FeatureSTFIWX, FeatureLFIWAX,
                    FeatureFPRND, FeatureFPCVT, FeatureISEL,
-                   FeaturePOPCNTD, SlowPOPCNTD, FeatureCMPB, FeatureLDBRX,
+                   FeatureSlowPOPCNTD, FeatureCMPB, FeatureLDBRX,
                    Feature64Bit /*, Feature64BitRegs */, FeatureMFTB]>;
 def : ProcessorModel<"a2q", PPCA2Model,
                   [DirectiveA2, FeatureICBT, FeatureBookE, FeatureMFOCRF,
@@ -351,7 +353,7 @@ def : ProcessorModel<"a2q", PPCA2Model,
                    FeatureFRSQRTE, FeatureFRSQRTES, FeatureRecipPrec,
                    FeatureSTFIWX, FeatureLFIWAX,
                    FeatureFPRND, FeatureFPCVT, FeatureISEL,
-                   FeaturePOPCNTD, SlowPOPCNTD, FeatureCMPB, FeatureLDBRX,
+                   FeatureSlowPOPCNTD, FeatureCMPB, FeatureLDBRX,
                    Feature64Bit /*, Feature64BitRegs */, FeatureQPX,
                    FeatureMFTB]>;
 def : ProcessorModel<"pwr3", G5Model,

lib/Target/PowerPC/PPCISelLowering.cpp

@@ -214,7 +214,7 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Expand);
   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Expand);
 
-  if (Subtarget.hasPOPCNTD() && !Subtarget.isPOPCNTDSlow()) {
+  if (Subtarget.hasPOPCNTD() == PPCSubtarget::POPCNTD_Fast) {
     setOperationAction(ISD::CTPOP, MVT::i32  , Legal);
     setOperationAction(ISD::CTPOP, MVT::i64  , Legal);
   } else {

lib/Target/PowerPC/PPCSubtarget.cpp

@@ -84,7 +84,6 @@ void PPCSubtarget::initializeEnvironment() {
   HasFPRND = false;
   HasFPCVT = false;
   HasISEL = false;
-  HasPOPCNTD = false;
   HasBPERMD = false;
   HasExtDiv = false;
   HasCMPB = false;
@@ -105,7 +104,8 @@ void PPCSubtarget::initializeEnvironment() {
   HasHTM = false;
   HasFusion = false;
   HasFloat128 = false;
-  SlowPOPCNTD = false;
+
+  HasPOPCNTD = POPCNTD_Unavailable;
 }
 
 void PPCSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {

lib/Target/PowerPC/PPCSubtarget.h

@@ -64,6 +64,13 @@ class GlobalValue;
 class TargetMachine;
 
 class PPCSubtarget : public PPCGenSubtargetInfo {
+public:
+  enum POPCNTDKind {
+    POPCNTD_Unavailable,
+    POPCNTD_Slow,
+    POPCNTD_Fast
+  };
+
 protected:
   /// TargetTriple - What processor and OS we're targeting.
   Triple TargetTriple;
@@ -103,7 +110,6 @@ protected:
   bool HasFPRND;
   bool HasFPCVT;
   bool HasISEL;
-  bool HasPOPCNTD;
   bool HasBPERMD;
   bool HasExtDiv;
   bool HasCMPB;
@@ -124,7 +130,8 @@ protected:
   bool HasHTM;
   bool HasFusion;
   bool HasFloat128;
-  bool SlowPOPCNTD;
+
+  POPCNTDKind HasPOPCNTD;
 
   /// When targeting QPX running a stock PPC64 Linux kernel where the stack
   /// alignment has not been changed, we need to keep the 16-byte alignment
@@ -237,7 +244,6 @@ public:
   bool hasP9Altivec() const { return HasP9Altivec; }
   bool hasMFOCRF() const { return HasMFOCRF; }
   bool hasISEL() const { return HasISEL; }
-  bool hasPOPCNTD() const { return HasPOPCNTD; }
   bool hasBPERMD() const { return HasBPERMD; }
   bool hasExtDiv() const { return HasExtDiv; }
   bool hasCMPB() const { return HasCMPB; }
@@ -249,7 +255,6 @@ public:
   bool isE500() const { return IsE500; }
   bool isFeatureMFTB() const { return FeatureMFTB; }
   bool isDeprecatedDST() const { return DeprecatedDST; }
-  bool isPOPCNTDSlow() const { return SlowPOPCNTD; }
   bool hasICBT() const { return HasICBT; }
   bool hasInvariantFunctionDescriptors() const {
     return HasInvariantFunctionDescriptors;
@@ -268,6 +273,8 @@ public:
   bool hasFusion() const { return HasFusion; }
   bool hasFloat128() const { return HasFloat128; }
 
+  POPCNTDKind hasPOPCNTD() const { return HasPOPCNTD; }
+
   const Triple &getTargetTriple() const { return TargetTriple; }
 
   /// isDarwin - True if this is any darwin platform.

lib/Target/PowerPC/PPCTargetTransformInfo.cpp

@@ -42,8 +42,9 @@ PrefDist("ppc-loop-prefetch-distance", cl::Hidden, cl::init(300),
 TargetTransformInfo::PopcntSupportKind
 PPCTTIImpl::getPopcntSupport(unsigned TyWidth) {
   assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2");
-  if (ST->hasPOPCNTD() && TyWidth <= 64)
-    return ST->isPOPCNTDSlow() ? TTI::PSK_SlowHardware : TTI::PSK_FastHardware;
+  if (ST->hasPOPCNTD() != PPCSubtarget::POPCNTD_Unavailable && TyWidth <= 64)
+    return ST->hasPOPCNTD() == PPCSubtarget::POPCNTD_Slow ?
+             TTI::PSK_SlowHardware : TTI::PSK_FastHardware;
   return TTI::PSK_Software;
 }
 

test/CodeGen/PowerPC/popcnt.ll

@@ -1,6 +1,8 @@
 ; RUN: llc -march=ppc64 -mattr=+popcntd < %s | FileCheck %s
+; RUN: llc -march=ppc64 -mattr=+slow-popcntd < %s | FileCheck %s --check-prefix=SLOWPC
 ; RUN: llc -march=ppc64 -mcpu=pwr7 < %s | FileCheck %s
 ; RUN: llc -march=ppc64 -mcpu=a2q < %s | FileCheck %s --check-prefix=SLOWPC
+; RUN: llc -march=ppc64 -mcpu=a2q -mattr=+popcntd < %s | FileCheck %s
 
 define i8 @cnt8(i8 %x) nounwind readnone {
   %cnt = tail call i8 @llvm.ctpop.i8(i8 %x)