- declare i8 @llvm.ctlz.i8 (i8 <src>) - declare i16 @llvm.ctlz.i16(i16 <src>) - declare i32 @llvm.ctlz.i32(i32 <src>) - declare i64 @llvm.ctlz.i64(i64 <src>) - declare i256 @llvm.ctlz.i256(i256 <src>) - declare <2 x i32> @llvm.ctlz.v2i32(<2 x i32> <src;gt) + declare i8 @llvm.ctlz.i8 (i8 <src>, i1 <is_zero_undef>) + declare i16 @llvm.ctlz.i16 (i16 <src>, i1 <is_zero_undef>) + declare i32 @llvm.ctlz.i32 (i32 <src>, i1 <is_zero_undef>) + declare i64 @llvm.ctlz.i64 (i64 <src>, i1 <is_zero_undef>) + declare i256 @llvm.ctlz.i256(i256 <src>, i1 <is_zero_undef>) + declase <2 x i32> @llvm.ctlz.v2i32(<2 x i32> <src>, i1 <is_zero_undef>)
The only argument is the value to be counted. The argument may be of any - integer type, or any vector type with integer element type. - The return type must match the argument type.
+The first argument is the value to be counted. This argument may be of any + integer type, or a vectory with integer element type. The return type + must match the first argument type.
+ +The second argument must be a constant and is a flag to indicate whether the + intrinsic should ensure that a zero as the first argument produces a defined + result. Historically some architectures did not provide a defined result for + zero values as efficiently, and many algorithms are now predicated on + avoiding zero-value inputs.
The 'llvm.ctlz' intrinsic counts the leading (most significant) - zeros in a variable, or within each element of the vector if the operation - is of vector type. If the src == 0 then the result is the size in bits of - the type of src. For example, llvm.ctlz(i32 2) = 30.
+ zeros in a variable, or within each element of the vector. + If src == 0 then the result is the size in bits of the type of + src if is_zero_undef == 0 and undef otherwise. + For example, llvm.ctlz(i32 2) = 30. @@ -7373,12 +7380,12 @@ LLVM. support all bit widths or vector types, however.- declare i8 @llvm.cttz.i8 (i8 <src>) - declare i16 @llvm.cttz.i16(i16 <src>) - declare i32 @llvm.cttz.i32(i32 <src>) - declare i64 @llvm.cttz.i64(i64 <src>) - declare i256 @llvm.cttz.i256(i256 <src>) - declase <2 x i32> @llvm.cttz.v2i32(<2 x i32> <src>) + declare i8 @llvm.cttz.i8 (i8 <src>, i1 <is_zero_undef>) + declare i16 @llvm.cttz.i16 (i16 <src>, i1 <is_zero_undef>) + declare i32 @llvm.cttz.i32 (i32 <src>, i1 <is_zero_undef>) + declare i64 @llvm.cttz.i64 (i64 <src>, i1 <is_zero_undef>) + declare i256 @llvm.cttz.i256(i256 <src>, i1 <is_zero_undef>) + declase <2 x i32> @llvm.cttz.v2i32(<2 x i32> <src>, i1 <is_zero_undef>)
The only argument is the value to be counted. The argument may be of any - integer type, or a vectory with integer element type.. The return type - must match the argument type.
+The first argument is the value to be counted. This argument may be of any + integer type, or a vectory with integer element type. The return type + must match the first argument type.
+ +The second argument must be a constant and is a flag to indicate whether the + intrinsic should ensure that a zero as the first argument produces a defined + result. Historically some architectures did not provide a defined result for + zero values as efficiently, and many algorithms are now predicated on + avoiding zero-value inputs.
The 'llvm.cttz' intrinsic counts the trailing (least significant) zeros in a variable, or within each element of a vector. - If the src == 0 then the result is the size in bits of - the type of src. For example, llvm.cttz(2) = 1.
+ If src == 0 then the result is the size in bits of the type of + src if is_zero_undef == 0 and undef otherwise. + For example, llvm.cttz(2) = 1.