[clang] Implement __builtin_popcountg

Fixes #82058.

Author: overmighty

clang/include/clang/Basic/Builtins.td

@@ -688,6 +688,12 @@ def Popcount : Builtin, BitInt_Long_LongLongTemplate {
   let Prototype = "int(unsigned T)";
 }
 
+def Popcountg : Builtin {
+  let Spellings = ["__builtin_popcountg"];
+  let Attributes = [NoThrow, Const, Constexpr];
+  let Prototype = "int(...)";
+}
+
 def Clrsb : Builtin, BitInt_Long_LongLongTemplate {
   let Spellings = ["__builtin_clrsb"];
   let Attributes = [NoThrow, Const, Constexpr];

clang/lib/CodeGen/CGBuiltin.cpp

@@ -3216,7 +3216,12 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
   case Builtin::BI__popcnt64:
   case Builtin::BI__builtin_popcount:
   case Builtin::BI__builtin_popcountl:
-  case Builtin::BI__builtin_popcountll: {
+  case Builtin::BI__builtin_popcountll:
+  case Builtin::BI__builtin_popcountg: {
+    if (BuiltinIDIfNoAsmLabel == Builtin::BI__builtin_popcountg) {
+      assert(E->getNumArgs() == 1 && "__builtin_popcountg takes 1 argument");
+    }
+
     Value *ArgValue = EmitScalarExpr(E->getArg(0));
 
     llvm::Type *ArgType = ArgValue->getType();

clang/test/CodeGen/builtins.c

@@ -940,4 +940,47 @@ void test_builtin_os_log_long_double(void *buf, long double ld) {
 // CHECK: %[[V3:.*]] = load i128, ptr %[[ARG0_ADDR]], align 16
 // CHECK: store i128 %[[V3]], ptr %[[ARGDATA]], align 1
 
+// CHECK-LABEL: define{{.*}} void @test_builtin_popcountg
+void test_builtin_popcountg(unsigned char uc, unsigned short us,
+                            unsigned int ui, unsigned long ul,
+                            unsigned long long ull, unsigned __int128 ui128,
+                            unsigned _BitInt(128) ubi128) {
+  volatile int pop;
+  pop = __builtin_popcountg(uc);
+  // CHECK: %1 = load i8, ptr %uc.addr, align 1
+  // CHECK-NEXT: %conv = zext i8 %1 to i32
+  // CHECK-NEXT: %2 = call i32 @llvm.ctpop.i32(i32 %conv)
+  // CHECK-NEXT: store volatile i32 %2, ptr %pop, align 4
+  pop = __builtin_popcountg(us);
+  // CHECK-NEXT: %3 = load i16, ptr %us.addr, align 2
+  // CHECK-NEXT: %conv1 = zext i16 %3 to i32
+  // CHECK-NEXT: %4 = call i32 @llvm.ctpop.i32(i32 %conv1)
+  // CHECK-NEXT: store volatile i32 %4, ptr %pop, align 4
+  pop = __builtin_popcountg(ui);
+  // CHECK-NEXT: %5 = load i32, ptr %ui.addr, align 4
+  // CHECK-NEXT: %6 = call i32 @llvm.ctpop.i32(i32 %5)
+  // CHECK-NEXT: store volatile i32 %6, ptr %pop, align 4
+  pop = __builtin_popcountg(ul);
+  // CHECK-NEXT: %7 = load i64, ptr %ul.addr, align 8
+  // CHECK-NEXT: %8 = call i64 @llvm.ctpop.i64(i64 %7)
+  // CHECK-NEXT: %cast = trunc i64 %8 to i32
+  // CHECK-NEXT: store volatile i32 %cast, ptr %pop, align 4
+  pop = __builtin_popcountg(ull);
+  // CHECK-NEXT: %9 = load i64, ptr %ull.addr, align 8
+  // CHECK-NEXT: %10 = call i64 @llvm.ctpop.i64(i64 %9)
+  // CHECK-NEXT: %cast2 = trunc i64 %10 to i32
+  // CHECK-NEXT: store volatile i32 %cast2, ptr %pop, align 4
+  pop = __builtin_popcountg(ui128);
+  // CHECK-NEXT: %11 = load i128, ptr %ui128.addr, align 16
+  // CHECK-NEXT: %12 = call i128 @llvm.ctpop.i128(i128 %11)
+  // CHECK-NEXT: %cast3 = trunc i128 %12 to i32
+  // CHECK-NEXT: store volatile i32 %cast3, ptr %pop, align 4
+  pop = __builtin_popcountg(ubi128);
+  // CHECK-NEXT: %13 = load i128, ptr %ubi128.addr, align 8
+  // CHECK-NEXT: %14 = call i128 @llvm.ctpop.i128(i128 %13)
+  // CHECK-NEXT: %cast4 = trunc i128 %14 to i32
+  // CHECK-NEXT: store volatile i32 %cast4, ptr %pop, align 4
+  // CHECK-NEXT: ret void
+}
+
 #endif