[POWER] vec_bperm missing documented signatures

[llvmbot]

Bugzilla Link	50932
Version	trunk
OS	Windows NT
Reporter	LLVM Bugzilla Contributor

Extended Description

According to the documentation for XL C/C++ 16.1.1 (https://www.ibm.com/docs/en/SSXVZZ_16.1.1/com.ibm.compilers.linux.doc/compiler.pdf), vec_bperm should have two signatures. On POWER8:

vector unsigned char
vec_bperm(vector unsigned char a, vector unsigned char b);

And on POWER9 there should also be:

vector unsigned long
vec_bperm(vector unsigned long long a, vector unsigned char b);

Neither of these is present in clang; instead, there is a single signature (see

llvm-project/clang/lib/Headers/altivec.h

Lines 17356 to 17363 in 5d933c0

	#if defined(__powerpc64__) && defined(__SIZEOF_INT128__)
	static __inline__ vector unsigned long long __attribute__((__always_inline__))
	vec_bperm(vector unsigned __int128 __a, vector unsigned char __b) {
	return __builtin_altivec_vbpermq((vector unsigned char)__a,
	(vector unsigned char)__b);
	}
	#endif
	#endif

) which doesn't match either of the documented signatures:

vector unsigned long long
vec_bperm(vector unsigned __int128 a, vector unsigned char b);

[mr-c]

The IBM manuals for Open XL C/C++ for Linux 16.1 - 17.1.1 list a variation on your request (returning vector unsigned long long instead of vector unsigned long):

vector unsigned long long
vec_bperm(vector unsigned long long a, vector unsigned char b);

Checking an archive of the manual you linked to shows the same definition
https://web.archive.org/web/20211206100745/https://www.ibm.com/docs/en/SSXVZZ_16.1.1/com.ibm.compilers.linux.doc/compiler.pdf

Looks like this was fixed in 09b67aa a.k.a https://reviews.llvm.org/D107899 as part of clang-14

Therefore I think this issue can be closed