From: Daniel Dunbar <daniel@zuster.org>
Date: Mon, 21 Jul 2008 17:19:41 +0000 (+0000)
Subject: Implement ffs, parity, and popcount builtins.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=04b290030eee33295600728450f348989d1a627e;p=clang

Implement ffs, parity, and popcount builtins.
 + test case


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@53851 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/AST/Builtins.def b/include/clang/AST/Builtins.def
index 7bdcd6dd8d..c3113a9148 100644
--- a/include/clang/AST/Builtins.def
+++ b/include/clang/AST/Builtins.def
@@ -55,6 +55,8 @@
 
 // Standard libc/libm functions:
 BUILTIN(__builtin_huge_val, "d", "nc")
+BUILTIN(__builtin_huge_valf, "f", "nc")
+BUILTIN(__builtin_huge_vall, "Ld", "nc")
 BUILTIN(__builtin_inf  , "d"   , "nc")
 BUILTIN(__builtin_inff , "f"   , "nc")
 BUILTIN(__builtin_infl , "Ld"  , "nc")
@@ -86,6 +88,15 @@ BUILTIN(__builtin_ctz  , "iUi"  , "nc")
 BUILTIN(__builtin_ctzl , "iULi" , "nc")
 BUILTIN(__builtin_ctzll, "iULLi", "nc")
 // TODO: int ctzimax(uintmax_t)
+BUILTIN(__builtin_ffs  , "iUi"  , "nc")
+BUILTIN(__builtin_ffsl , "iULi" , "nc")
+BUILTIN(__builtin_ffsll, "iULLi", "nc")
+BUILTIN(__builtin_parity  , "iUi"  , "nc")
+BUILTIN(__builtin_parityl , "iULi" , "nc")
+BUILTIN(__builtin_parityll, "iULLi", "nc")
+BUILTIN(__builtin_popcount  , "iUi"  , "nc")
+BUILTIN(__builtin_popcountl , "iULi" , "nc")
+BUILTIN(__builtin_popcountll, "iULLi", "nc")
 
 // FIXME: These type signatures are not correct for targets with int != 32-bits
 // or with ULL != 64-bits.
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index fb6b0caa3d..d186a71619 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -140,6 +140,57 @@ RValue CodeGenFunction::EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
       Result = Builder.CreateIntCast(Result, ResultType, "cast");
     return RValue::get(Result);
   }
+  case Builtin::BI__builtin_ffs:
+  case Builtin::BI__builtin_ffsl:
+  case Builtin::BI__builtin_ffsll: {
+    // ffs(x) -> x ? cttz(x) + 1 : 0
+    Value *ArgValue = EmitScalarExpr(E->getArg(0));
+    
+    const llvm::Type *ArgType = ArgValue->getType();
+    Value *F = CGM.getIntrinsic(Intrinsic::cttz, &ArgType, 1);
+        
+    const llvm::Type *ResultType = ConvertType(E->getType());
+    Value *Tmp = Builder.CreateAdd(Builder.CreateCall(F, ArgValue, "tmp"), 
+                                   ConstantInt::get(ArgType, 1), "tmp");
+    Value *Zero = llvm::Constant::getNullValue(ArgType);
+    Value *IsZero = Builder.CreateICmpEQ(ArgValue, Zero, "iszero");
+    Value *Result = Builder.CreateSelect(IsZero, Zero, Tmp, "ffs");
+    if (Result->getType() != ResultType)
+      Result = Builder.CreateIntCast(Result, ResultType, "cast");
+    return RValue::get(Result);
+  }
+  case Builtin::BI__builtin_parity:
+  case Builtin::BI__builtin_parityl:
+  case Builtin::BI__builtin_parityll: {
+    // parity(x) -> ctpop(x) & 1
+    Value *ArgValue = EmitScalarExpr(E->getArg(0));
+    
+    const llvm::Type *ArgType = ArgValue->getType();
+    Value *F = CGM.getIntrinsic(Intrinsic::ctpop, &ArgType, 1);
+    
+    const llvm::Type *ResultType = ConvertType(E->getType());
+    Value *Tmp = Builder.CreateCall(F, ArgValue, "tmp");
+    Value *Result = Builder.CreateAnd(Tmp, ConstantInt::get(ArgType, 1), 
+                                      "tmp");
+    if (Result->getType() != ResultType)
+      Result = Builder.CreateIntCast(Result, ResultType, "cast");
+    return RValue::get(Result);
+  }
+  case Builtin::BI__builtin_popcount:
+  case Builtin::BI__builtin_popcountl:
+  case Builtin::BI__builtin_popcountll: {
+    Value *ArgValue = EmitScalarExpr(E->getArg(0));
+    
+    const llvm::Type *ArgType = ArgValue->getType();
+    Value *F = CGM.getIntrinsic(Intrinsic::ctpop, &ArgType, 1);
+    
+    const llvm::Type *ResultType = ConvertType(E->getType());
+    Value *Result = Builder.CreateCall(F, ArgValue, "tmp");
+    if (Result->getType() != ResultType)
+      Result = Builder.CreateIntCast(Result, ResultType, "cast");
+    return RValue::get(Result);
+  }
+
   case Builtin::BI__builtin_expect:
     return RValue::get(EmitScalarExpr(E->getArg(0)));
   case Builtin::BI__builtin_bswap32:
@@ -149,16 +200,18 @@ RValue CodeGenFunction::EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
     Value *F = CGM.getIntrinsic(Intrinsic::bswap, &ArgType, 1);
     return RValue::get(Builder.CreateCall(F, ArgValue, "tmp"));
   }
-  case Builtin::BI__builtin_inff:
   case Builtin::BI__builtin_huge_val:
+  case Builtin::BI__builtin_huge_valf:
+  case Builtin::BI__builtin_huge_vall:
   case Builtin::BI__builtin_inf:
+  case Builtin::BI__builtin_inff:
   case Builtin::BI__builtin_infl: {
     const llvm::fltSemantics &Sem =
       CGM.getContext().getFloatTypeSemantics(E->getType());
     return RValue::get(ConstantFP::get(APFloat::getInf(Sem)));
   }
-  case Builtin::BI__builtin_nanf:
   case Builtin::BI__builtin_nan:
+  case Builtin::BI__builtin_nanf:
   case Builtin::BI__builtin_nanl: {
     // If this is __builtin_nan("") turn this into a simple nan, otherwise just
     // call libm nan.
diff --git a/test/CodeGen/builtins-ffs_parity_popcount.c b/test/CodeGen/builtins-ffs_parity_popcount.c
new file mode 100644
index 0000000000..19a5cf9a67
--- /dev/null
+++ b/test/CodeGen/builtins-ffs_parity_popcount.c
@@ -0,0 +1,15 @@
+// RUN: clang -emit-llvm -o - %s > %t
+// RUN: ! grep "__builtin" %t
+
+#include <stdio.h>
+
+void test(int M, long long N) {
+  printf("%d %lld: %d %d %d %d %d %d %d %d %d %d %d %d %d %d %d %d %d %d\n",
+         M, N,
+         __builtin_ffs(M), __builtin_ffsl(M), __builtin_ffsll(M),
+         __builtin_parity(M), __builtin_parityl(M), __builtin_parityll(M),
+         __builtin_popcount(M), __builtin_popcountl(M), __builtin_popcountll(M),
+         __builtin_ffs(N), __builtin_ffsl(N), __builtin_ffsll(N),
+         __builtin_parity(N), __builtin_parityl(N), __builtin_parityll(N),
+         __builtin_popcount(N), __builtin_popcountl(N), __builtin_popcountll(N));
+}