Implement a subset of builtin_cpu_supports() features (#82809)

The PR implements a subset of features of function
__builtin_cpu_support() for AIX OS based on the information which AIX
kernel runtime variable `_system_configuration` and function call `getsystemcfg()` of
/usr/include/sys/systemcfg.h  in AIX OS can provide.

Following subset of features are supported in the PR

"arch_3_00", "arch_3_1","booke","cellbe","darn","dfp","dscr" ,"ebb","efpsingle","efpdouble","fpu","htm","isel",
"mma","mmu","pa6t","power4","power5","power5+","power6x","ppc32","ppc601","ppc64","ppcle","smt",
"spe","tar","true_le","ucache","vsx"

Author: diggerlin

clang/lib/Basic/Targets/PPC.cpp

@@ -901,6 +901,19 @@ ArrayRef<Builtin::Info> PPCTargetInfo::getTargetBuiltins() const {
 }
 
 bool PPCTargetInfo::validateCpuSupports(StringRef FeatureStr) const {
+  llvm::Triple Triple = getTriple();
+  if (Triple.isOSAIX()) {
+#define PPC_AIX_FEATURE(NAME, DESC, SUPPORT_METHOD, INDEX, MASK, COMP_OP,      \
+                        VALUE)                                                 \
+  .Case(NAME, true)
+    return llvm::StringSwitch<bool>(FeatureStr)
+#include "llvm/TargetParser/PPCTargetParser.def"
+        .Default(false);
+  }
+
+  assert(Triple.isOSLinux() &&
+         "__builtin_cpu_supports() is only supported for AIX and Linux.");
+
 #define PPC_LNX_FEATURE(NAME, DESC, ENUMNAME, ENUMVAL, HWCAPN) .Case(NAME, true)
   return llvm::StringSwitch<bool>(FeatureStr)
 #include "llvm/TargetParser/PPCTargetParser.def"
@@ -910,7 +923,7 @@ bool PPCTargetInfo::validateCpuSupports(StringRef FeatureStr) const {
 bool PPCTargetInfo::validateCpuIs(StringRef CPUName) const {
   llvm::Triple Triple = getTriple();
   if (Triple.isOSAIX()) {
-#define PPC_AIX_CPU(NAME, SUPPORT, INDEX, OP, VALUE) .Case(NAME, true)
+#define PPC_AIX_CPU(NAME, SUPPORT_METHOD, INDEX, OP, VALUE) .Case(NAME, true)
     return llvm::StringSwitch<bool>(CPUName)
 #include "llvm/TargetParser/PPCTargetParser.def"
         .Default(false);

clang/lib/Basic/Targets/PPC.h

@@ -366,7 +366,14 @@ class LLVM_LIBRARY_VISIBILITY PPCTargetInfo : public TargetInfo {
   // have Glibc since it is Glibc that provides the HWCAP[2] in the auxv.
   static constexpr int MINIMUM_AIX_OS_MAJOR = 7;
   static constexpr int MINIMUM_AIX_OS_MINOR = 2;
-  bool supportsCpuSupports() const override { return getTriple().isOSGlibc(); }
+  bool supportsCpuSupports() const override {
+    llvm::Triple Triple = getTriple();
+    // AIX 7.2 is the minimum requirement to support __builtin_cpu_supports().
+    return Triple.isOSGlibc() ||
+           (Triple.isOSAIX() &&
+            !Triple.isOSVersionLT(MINIMUM_AIX_OS_MAJOR, MINIMUM_AIX_OS_MINOR));
+  }
+
   bool supportsCpuIs() const override {
     llvm::Triple Triple = getTriple();
     // AIX 7.2 is the minimum requirement to support __builtin_cpu_is().

clang/lib/CodeGen/CGBuiltin.cpp

@@ -16783,32 +16783,53 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
 
 #include "llvm/TargetParser/PPCTargetParser.def"
   auto GenAIXPPCBuiltinCpuExpr = [&](unsigned SupportMethod, unsigned FieldIdx,
-                                     unsigned CompOp,
+                                     unsigned Mask, CmpInst::Predicate CompOp,
                                      unsigned OpValue) -> Value * {
     if (SupportMethod == AIX_BUILTIN_PPC_FALSE)
       return llvm::ConstantInt::getFalse(ConvertType(E->getType()));
 
     if (SupportMethod == AIX_BUILTIN_PPC_TRUE)
       return llvm::ConstantInt::getTrue(ConvertType(E->getType()));
 
-    assert(SupportMethod <= USE_SYS_CONF && "Invalid value for SupportMethod.");
-    assert((CompOp == COMP_EQ) && "Only equal comparisons are supported.");
+    assert(SupportMethod <= SYS_CALL && "Invalid value for SupportMethod.");
+
+    llvm::Value *FieldValue = nullptr;
+    if (SupportMethod == USE_SYS_CONF) {
+      llvm::Type *STy = llvm::StructType::get(PPC_SYSTEMCONFIG_TYPE);
+      llvm::Constant *SysConf =
+          CGM.CreateRuntimeVariable(STy, "_system_configuration");
+
+      // Grab the appropriate field from _system_configuration.
+      llvm::Value *Idxs[] = {ConstantInt::get(Int32Ty, 0),
+                             ConstantInt::get(Int32Ty, FieldIdx)};
+
+      FieldValue = Builder.CreateGEP(STy, SysConf, Idxs);
+      FieldValue = Builder.CreateAlignedLoad(Int32Ty, FieldValue,
+                                             CharUnits::fromQuantity(4));
+    } else if (SupportMethod == SYS_CALL) {
+      llvm::FunctionType *FTy =
+          llvm::FunctionType::get(Int64Ty, Int32Ty, false);
+      llvm::FunctionCallee Func =
+          CGM.CreateRuntimeFunction(FTy, "getsystemcfg");
+
+      FieldValue =
+          Builder.CreateCall(Func, {ConstantInt::get(Int32Ty, FieldIdx)});
+    }
+    assert(FieldValue &&
+           "SupportMethod value is not defined in PPCTargetParser.def.");
 
-    llvm::Type *STy = llvm::StructType::get(PPC_SYSTEMCONFIG_TYPE);
-    llvm::Constant *SysConf =
-        CGM.CreateRuntimeVariable(STy, "_system_configuration");
+    if (Mask)
+      FieldValue = Builder.CreateAnd(FieldValue, Mask);
 
-    // Grab the appropriate field from _system_configuration.
-    llvm::Value *Idxs[] = {ConstantInt::get(Int32Ty, 0),
-                           ConstantInt::get(Int32Ty, FieldIdx)};
+    llvm::Type *ValueType = FieldValue->getType();
+    bool IsValueType64Bit = ValueType->isIntegerTy(64);
+    assert(
+        (IsValueType64Bit || ValueType->isIntegerTy(32)) &&
+        "Only 32/64-bit integers are supported in GenAIXPPCBuiltinCpuExpr().");
 
-    llvm::Value *FieldValue = Builder.CreateGEP(STy, SysConf, Idxs);
-    FieldValue = Builder.CreateAlignedLoad(Int32Ty, FieldValue,
-                                           CharUnits::fromQuantity(4));
-    assert(FieldValue->getType()->isIntegerTy(32) &&
-           "Only 32-bit integers are supported in GenAIXPPCBuiltinCpuExpr().");
-    return Builder.CreateICmp(ICmpInst::ICMP_EQ, FieldValue,
-                              ConstantInt::get(Int32Ty, OpValue));
+    return Builder.CreateICmp(
+        CompOp, FieldValue,
+        ConstantInt::get(IsValueType64Bit ? Int64Ty : Int32Ty, OpValue));
   };
 
   switch (BuiltinID) {
@@ -16820,15 +16841,18 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
     llvm::Triple Triple = getTarget().getTriple();
 
     if (Triple.isOSAIX()) {
-      unsigned IsCpuSupport, FieldIdx, CompareOp, CpuIdValue;
-      typedef std::tuple<unsigned, unsigned, unsigned, unsigned> CPUType;
-      std::tie(IsCpuSupport, FieldIdx, CompareOp, CpuIdValue) =
+      unsigned SupportMethod, FieldIdx, CpuIdValue;
+      CmpInst::Predicate CompareOp;
+      typedef std::tuple<unsigned, unsigned, CmpInst::Predicate, unsigned>
+          CPUType;
+      std::tie(SupportMethod, FieldIdx, CompareOp, CpuIdValue) =
           static_cast<CPUType>(StringSwitch<CPUType>(CPUStr)
-#define PPC_AIX_CPU(NAME, SUPPORT_MAGIC, INDEX, COMPARE_OP, VALUE)             \
-  .Case(NAME, {SUPPORT_MAGIC, INDEX, COMPARE_OP, VALUE})
+#define PPC_AIX_CPU(NAME, SUPPORT_METHOD, INDEX, COMPARE_OP, VALUE)            \
+  .Case(NAME, {SUPPORT_METHOD, INDEX, COMPARE_OP, VALUE})
 #include "llvm/TargetParser/PPCTargetParser.def"
-          );
-      return GenAIXPPCBuiltinCpuExpr(IsCpuSupport, FieldIdx, CompareOp,
+                                   .Default({AIX_BUILTIN_PPC_FALSE, 0,
+                                             CmpInst::Predicate(), 0}));
+      return GenAIXPPCBuiltinCpuExpr(SupportMethod, FieldIdx, 0, CompareOp,
                                      CpuIdValue);
     }
 
@@ -16846,10 +16870,31 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
                                 llvm::ConstantInt::get(Int32Ty, NumCPUID));
   }
   case Builtin::BI__builtin_cpu_supports: {
-    unsigned FeatureWord;
-    unsigned BitMask;
+    llvm::Triple Triple = getTarget().getTriple();
     const Expr *CPUExpr = E->getArg(0)->IgnoreParenCasts();
     StringRef CPUStr = cast<clang::StringLiteral>(CPUExpr)->getString();
+    if (Triple.isOSAIX()) {
+      unsigned SupportMethod, FieldIdx, Mask, Value;
+      CmpInst::Predicate CompOp;
+      typedef std::tuple<unsigned, unsigned, unsigned, CmpInst::Predicate,
+                         unsigned>
+          CPUSupportType;
+      std::tie(SupportMethod, FieldIdx, Mask, CompOp, Value) =
+          static_cast<CPUSupportType>(StringSwitch<CPUSupportType>(CPUStr)
+#define PPC_AIX_FEATURE(NAME, DESC, SUPPORT_METHOD, INDEX, MASK, COMP_OP,      \
+                        VALUE)                                                 \
+  .Case(NAME, {SUPPORT_METHOD, INDEX, MASK, COMP_OP, VALUE})
+#include "llvm/TargetParser/PPCTargetParser.def"
+                                          .Default({AIX_BUILTIN_PPC_FALSE, 0, 0,
+                                                    CmpInst::Predicate(), 0}));
+      return GenAIXPPCBuiltinCpuExpr(SupportMethod, FieldIdx, Mask, CompOp,
+                                     Value);
+    }
+
+    assert(Triple.isOSLinux() &&
+           "__builtin_cpu_supports() is only supported for AIX and Linux.");
+    unsigned FeatureWord;
+    unsigned BitMask;
     std::tie(FeatureWord, BitMask) =
         StringSwitch<std::pair<unsigned, unsigned>>(CPUStr)
 #define PPC_LNX_FEATURE(Name, Description, EnumName, Bitmask, FA_WORD)         \

clang/lib/Sema/SemaChecking.cpp

@@ -2346,10 +2346,8 @@ static bool BuiltinCpu(Sema &S, const TargetInfo &TI, CallExpr *TheCall,
   if (!SupportsBI(&TI) && SupportsBI(AuxTI))
     TheTI = AuxTI;
 
-  if (IsCPUSupports && !TheTI->supportsCpuSupports())
-    return S.Diag(TheCall->getBeginLoc(), diag::err_builtin_target_unsupported)
-           << SourceRange(TheCall->getBeginLoc(), TheCall->getEndLoc());
-  if (!IsCPUSupports && !TheTI->supportsCpuIs())
+  if ((!IsCPUSupports && !TheTI->supportsCpuIs()) ||
+      (IsCPUSupports && !TheTI->supportsCpuSupports()))
     return S.Diag(TheCall->getBeginLoc(),
                   TI.getTriple().isOSAIX()
                       ? diag::err_builtin_aix_os_unsupported

clang/test/CodeGen/aix-builtin-cpu-is.c

@@ -57,12 +57,12 @@
 // CHECK-NEXT:   ret i32 0
 // CHECK-NEXT: }
 
-// CHECKOP: @_system_configuration = external global { i32, i32, i32 }
+// CHECKOP: @_system_configuration = external global { i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i64, i32, i32, i32, i32, i64, i64, i64, i64, i32, i32, i32, i32, i32, i32, i64, i32, i8, i8, i8, i8, i32, i32, i16, i16, [3 x i32], i32 }
 // CHECKOP:   define i32 @main() #0 {
 // CHECKOP-NEXT: entry:
 // CHECKOP-NEXT:   %retval = alloca i32, align 4
 // CHECKOP-NEXT:   store i32 0, ptr %retval, align 4
-// CHECKOP-NEXT:   %0 = load i32, ptr getelementptr inbounds ({ i32, i32, i32 }, ptr @_system_configuration, i32 0, i32 1), align 4
+// CHECKOP-NEXT:   %0 = load i32, ptr getelementptr inbounds ({ i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i64, i32, i32, i32, i32, i64, i64, i64, i64, i32, i32, i32, i32, i32, i32, i64, i32, i8, i8, i8, i8, i32, i32, i16, i16, [3 x i32], i32 }, ptr @_system_configuration, i32 0, i32 1), align 4
 // CHECKOP-NEXT:   %1 = icmp eq i32 %0, [[VALUE]] 
 // CHECKOP-NEXT:  %conv = zext i1 %1 to i32
 // CHECKOP-NEXT:   ret i32 %conv