r210340 - [PPC64LE] Implement little-endian semantics for vec_pack family
Hal Finkel
hfinkel at anl.gov
Fri Jun 6 09:07:01 PDT 2014
----- Original Message -----
> From: "Bill Schmidt" <wschmidt at linux.vnet.ibm.com>
> To: cfe-commits at cs.uiuc.edu
> Sent: Friday, June 6, 2014 10:10:47 AM
> Subject: r210340 - [PPC64LE] Implement little-endian semantics for vec_pack family
>
> Author: wschmidt
> Date: Fri Jun 6 10:10:47 2014
> New Revision: 210340
>
> URL: http://llvm.org/viewvc/llvm-project?rev=210340&view=rev
> Log:
> [PPC64LE] Implement little-endian semantics for vec_pack family
>
> The PowerPC vector-pack instructions are defined architecturally with
> a big-endian bias, in that the vector element numbering is assumed to
> be "left to right" regardless of whether the processor is in
> big-endian or little-endian mode. This definition is unnatural for
> little-endian code generation.
>
> To facilitate ease of porting, the vec_pack and related interfaces
> are
> designed to use natural element ordering, so that elements are
> numbered according to little-endian design principles when code is
> generated for a little-endian target. The vec_pack calls are
> implemented as calls to vec_perm, specifying selection of the
> odd-numbered vector elements. For little endian, this means the
> odd-numbered elements counting from the right end of the register.
> Since the underlying instructions count from the left end, we must
> instead select the even-numbered vector elements for little endian to
> achieve the desired semantics.
>
> The correctness of this code is tested by the new pack.c test added
> in
> a previous patch. I plan to later make the existing ppc32 Altivec
> compile-time tests work for ppc64 and ppc64le as well.
I don't understand this...
test/CodeGen/builtins-ppc-altivec.c seems to be the relevant place to test this, and this test works fine on ppc64 (if you change the current triple from powerpc-unknown-unknown to powerpc64-unknown-unknown it still passes). Please do this and add tests for these changes there.
Thanks again,
Hal
>
> Modified:
> cfe/trunk/lib/Headers/altivec.h
>
> Modified: cfe/trunk/lib/Headers/altivec.h
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Headers/altivec.h?rev=210340&r1=210339&r2=210340&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Headers/altivec.h (original)
> +++ cfe/trunk/lib/Headers/altivec.h Fri Jun 6 10:10:47 2014
> @@ -4117,52 +4117,91 @@ vec_vor(vector float __a, vector bool in
>
> /* vec_pack */
>
> +/* The various vector pack instructions have a big-endian bias, so
> for
> + little endian we must handle reversed element numbering. */
> +
> static vector signed char __ATTRS_o_ai
> vec_pack(vector signed short __a, vector signed short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector signed char)vec_perm(__a, __b, (vector unsigned
> char)
> + (0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E,
> + 0x10, 0x12, 0x14, 0x16, 0x18, 0x1A, 0x1C, 0x1E));
> +#else
> return (vector signed char)vec_perm(__a, __b, (vector unsigned
> char)
> (0x01, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0F,
> 0x11, 0x13, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F));
> +#endif
> }
>
> static vector unsigned char __ATTRS_o_ai
> vec_pack(vector unsigned short __a, vector unsigned short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector unsigned char)vec_perm(__a, __b, (vector unsigned
> char)
> + (0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E,
> + 0x10, 0x12, 0x14, 0x16, 0x18, 0x1A, 0x1C, 0x1E));
> +#else
> return (vector unsigned char)vec_perm(__a, __b, (vector unsigned
> char)
> (0x01, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0F,
> 0x11, 0x13, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F));
> +#endif
> }
>
> static vector bool char __ATTRS_o_ai
> vec_pack(vector bool short __a, vector bool short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector bool char)vec_perm(__a, __b, (vector unsigned char)
> + (0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E,
> + 0x10, 0x12, 0x14, 0x16, 0x18, 0x1A, 0x1C, 0x1E));
> +#else
> return (vector bool char)vec_perm(__a, __b, (vector unsigned char)
> (0x01, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0F,
> 0x11, 0x13, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F));
> +#endif
> }
>
> static vector short __ATTRS_o_ai
> vec_pack(vector int __a, vector int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector short)vec_perm(__a, __b, (vector unsigned char)
> + (0x00, 0x01, 0x04, 0x05, 0x08, 0x09, 0x0C, 0x0D,
> + 0x10, 0x11, 0x14, 0x15, 0x18, 0x19, 0x1C, 0x1D));
> +#else
> return (vector short)vec_perm(__a, __b, (vector unsigned char)
> (0x02, 0x03, 0x06, 0x07, 0x0A, 0x0B, 0x0E, 0x0F,
> 0x12, 0x13, 0x16, 0x17, 0x1A, 0x1B, 0x1E, 0x1F));
> +#endif
> }
>
> static vector unsigned short __ATTRS_o_ai
> vec_pack(vector unsigned int __a, vector unsigned int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector unsigned short)vec_perm(__a, __b, (vector unsigned
> char)
> + (0x00, 0x01, 0x04, 0x05, 0x08, 0x09, 0x0C, 0x0D,
> + 0x10, 0x11, 0x14, 0x15, 0x18, 0x19, 0x1C, 0x1D));
> +#else
> return (vector unsigned short)vec_perm(__a, __b, (vector unsigned
> char)
> (0x02, 0x03, 0x06, 0x07, 0x0A, 0x0B, 0x0E, 0x0F,
> 0x12, 0x13, 0x16, 0x17, 0x1A, 0x1B, 0x1E, 0x1F));
> +#endif
> }
>
> static vector bool short __ATTRS_o_ai
> vec_pack(vector bool int __a, vector bool int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector unsigned short)vec_perm(__a, __b, (vector unsigned
> char)
> + (0x00, 0x01, 0x04, 0x05, 0x08, 0x09, 0x0C, 0x0D,
> + 0x10, 0x11, 0x14, 0x15, 0x18, 0x19, 0x1C, 0x1D));
> +#else
> return (vector bool short)vec_perm(__a, __b, (vector unsigned
> char)
> (0x02, 0x03, 0x06, 0x07, 0x0A, 0x0B, 0x0E, 0x0F,
> 0x12, 0x13, 0x16, 0x17, 0x1A, 0x1B, 0x1E, 0x1F));
> +#endif
> }
>
> /* vec_vpkuhum */
> @@ -4172,25 +4211,43 @@ vec_pack(vector bool int __a, vector boo
> static vector signed char __ATTRS_o_ai
> vec_vpkuhum(vector signed short __a, vector signed short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector signed char)vec_perm(__a, __b, (vector unsigned
> char)
> + (0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E,
> + 0x10, 0x12, 0x14, 0x16, 0x18, 0x1A, 0x1C, 0x1E));
> +#else
> return (vector signed char)vec_perm(__a, __b, (vector unsigned
> char)
> (0x01, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0F,
> 0x11, 0x13, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F));
> +#endif
> }
>
> static vector unsigned char __ATTRS_o_ai
> vec_vpkuhum(vector unsigned short __a, vector unsigned short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector unsigned char)vec_perm(__a, __b, (vector unsigned
> char)
> + (0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E,
> + 0x10, 0x12, 0x14, 0x16, 0x18, 0x1A, 0x1C, 0x1E));
> +#else
> return (vector unsigned char)vec_perm(__a, __b, (vector unsigned
> char)
> (0x01, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0F,
> 0x11, 0x13, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F));
> +#endif
> }
>
> static vector bool char __ATTRS_o_ai
> vec_vpkuhum(vector bool short __a, vector bool short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector bool char)vec_perm(__a, __b, (vector unsigned char)
> + (0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E,
> + 0x10, 0x12, 0x14, 0x16, 0x18, 0x1A, 0x1C, 0x1E));
> +#else
> return (vector bool char)vec_perm(__a, __b, (vector unsigned char)
> (0x01, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0F,
> 0x11, 0x13, 0x15, 0x17, 0x19, 0x1B, 0x1D, 0x1F));
> +#endif
> }
>
> /* vec_vpkuwum */
> @@ -4200,25 +4257,43 @@ vec_vpkuhum(vector bool short __a, vecto
> static vector short __ATTRS_o_ai
> vec_vpkuwum(vector int __a, vector int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector short)vec_perm(__a, __b, (vector unsigned char)
> + (0x00, 0x01, 0x04, 0x05, 0x08, 0x09, 0x0C, 0x0D,
> + 0x10, 0x11, 0x14, 0x15, 0x18, 0x19, 0x1C, 0x1D));
> +#else
> return (vector short)vec_perm(__a, __b, (vector unsigned char)
> (0x02, 0x03, 0x06, 0x07, 0x0A, 0x0B, 0x0E, 0x0F,
> 0x12, 0x13, 0x16, 0x17, 0x1A, 0x1B, 0x1E, 0x1F));
> +#endif
> }
>
> static vector unsigned short __ATTRS_o_ai
> vec_vpkuwum(vector unsigned int __a, vector unsigned int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector unsigned short)vec_perm(__a, __b, (vector unsigned
> char)
> + (0x00, 0x01, 0x04, 0x05, 0x08, 0x09, 0x0C, 0x0D,
> + 0x10, 0x11, 0x14, 0x15, 0x18, 0x19, 0x1C, 0x1D));
> +#else
> return (vector unsigned short)vec_perm(__a, __b, (vector unsigned
> char)
> (0x02, 0x03, 0x06, 0x07, 0x0A, 0x0B, 0x0E, 0x0F,
> 0x12, 0x13, 0x16, 0x17, 0x1A, 0x1B, 0x1E, 0x1F));
> +#endif
> }
>
> static vector bool short __ATTRS_o_ai
> vec_vpkuwum(vector bool int __a, vector bool int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector bool short)vec_perm(__a, __b, (vector unsigned
> char)
> + (0x00, 0x01, 0x04, 0x05, 0x08, 0x09, 0x0C, 0x0D,
> + 0x10, 0x11, 0x14, 0x15, 0x18, 0x19, 0x1C, 0x1D));
> +#else
> return (vector bool short)vec_perm(__a, __b, (vector unsigned
> char)
> (0x02, 0x03, 0x06, 0x07, 0x0A, 0x0B, 0x0E, 0x0F,
> 0x12, 0x13, 0x16, 0x17, 0x1A, 0x1B, 0x1E, 0x1F));
> +#endif
> }
>
> /* vec_packpx */
> @@ -4226,7 +4301,11 @@ vec_vpkuwum(vector bool int __a, vector
> static vector pixel __attribute__((__always_inline__))
> vec_packpx(vector unsigned int __a, vector unsigned int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector pixel)__builtin_altivec_vpkpx(__b, __a);
> +#else
> return (vector pixel)__builtin_altivec_vpkpx(__a, __b);
> +#endif
> }
>
> /* vec_vpkpx */
> @@ -4234,7 +4313,11 @@ vec_packpx(vector unsigned int __a, vect
> static vector pixel __attribute__((__always_inline__))
> vec_vpkpx(vector unsigned int __a, vector unsigned int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return (vector pixel)__builtin_altivec_vpkpx(__b, __a);
> +#else
> return (vector pixel)__builtin_altivec_vpkpx(__a, __b);
> +#endif
> }
>
> /* vec_packs */
> @@ -4242,25 +4325,41 @@ vec_vpkpx(vector unsigned int __a, vecto
> static vector signed char __ATTRS_o_ai
> vec_packs(vector short __a, vector short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkshss(__b, __a);
> +#else
> return __builtin_altivec_vpkshss(__a, __b);
> +#endif
> }
>
> static vector unsigned char __ATTRS_o_ai
> vec_packs(vector unsigned short __a, vector unsigned short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkuhus(__b, __a);
> +#else
> return __builtin_altivec_vpkuhus(__a, __b);
> +#endif
> }
>
> static vector signed short __ATTRS_o_ai
> vec_packs(vector int __a, vector int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkswss(__b, __a);
> +#else
> return __builtin_altivec_vpkswss(__a, __b);
> +#endif
> }
>
> static vector unsigned short __ATTRS_o_ai
> vec_packs(vector unsigned int __a, vector unsigned int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkuwus(__b, __a);
> +#else
> return __builtin_altivec_vpkuwus(__a, __b);
> +#endif
> }
>
> /* vec_vpkshss */
> @@ -4268,7 +4367,11 @@ vec_packs(vector unsigned int __a, vecto
> static vector signed char __attribute__((__always_inline__))
> vec_vpkshss(vector short __a, vector short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkshss(__b, __a);
> +#else
> return __builtin_altivec_vpkshss(__a, __b);
> +#endif
> }
>
> /* vec_vpkuhus */
> @@ -4276,7 +4379,11 @@ vec_vpkshss(vector short __a, vector sho
> static vector unsigned char __attribute__((__always_inline__))
> vec_vpkuhus(vector unsigned short __a, vector unsigned short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkuhus(__b, __a);
> +#else
> return __builtin_altivec_vpkuhus(__a, __b);
> +#endif
> }
>
> /* vec_vpkswss */
> @@ -4284,7 +4391,11 @@ vec_vpkuhus(vector unsigned short __a, v
> static vector signed short __attribute__((__always_inline__))
> vec_vpkswss(vector int __a, vector int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkswss(__b, __a);
> +#else
> return __builtin_altivec_vpkswss(__a, __b);
> +#endif
> }
>
> /* vec_vpkuwus */
> @@ -4292,7 +4403,11 @@ vec_vpkswss(vector int __a, vector int _
> static vector unsigned short __attribute__((__always_inline__))
> vec_vpkuwus(vector unsigned int __a, vector unsigned int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkuwus(__b, __a);
> +#else
> return __builtin_altivec_vpkuwus(__a, __b);
> +#endif
> }
>
> /* vec_packsu */
> @@ -4300,25 +4415,41 @@ vec_vpkuwus(vector unsigned int __a, vec
> static vector unsigned char __ATTRS_o_ai
> vec_packsu(vector short __a, vector short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkshus(__b, __a);
> +#else
> return __builtin_altivec_vpkshus(__a, __b);
> +#endif
> }
>
> static vector unsigned char __ATTRS_o_ai
> vec_packsu(vector unsigned short __a, vector unsigned short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkuhus(__b, __a);
> +#else
> return __builtin_altivec_vpkuhus(__a, __b);
> +#endif
> }
>
> static vector unsigned short __ATTRS_o_ai
> vec_packsu(vector int __a, vector int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkswus(__b, __a);
> +#else
> return __builtin_altivec_vpkswus(__a, __b);
> +#endif
> }
>
> static vector unsigned short __ATTRS_o_ai
> vec_packsu(vector unsigned int __a, vector unsigned int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkuwus(__b, __a);
> +#else
> return __builtin_altivec_vpkuwus(__a, __b);
> +#endif
> }
>
> /* vec_vpkshus */
> @@ -4326,13 +4457,21 @@ vec_packsu(vector unsigned int __a, vect
> static vector unsigned char __ATTRS_o_ai
> vec_vpkshus(vector short __a, vector short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkshus(__b, __a);
> +#else
> return __builtin_altivec_vpkshus(__a, __b);
> +#endif
> }
>
> static vector unsigned char __ATTRS_o_ai
> vec_vpkshus(vector unsigned short __a, vector unsigned short __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkuhus(__b, __a);
> +#else
> return __builtin_altivec_vpkuhus(__a, __b);
> +#endif
> }
>
> /* vec_vpkswus */
> @@ -4340,13 +4479,21 @@ vec_vpkshus(vector unsigned short __a, v
> static vector unsigned short __ATTRS_o_ai
> vec_vpkswus(vector int __a, vector int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkswus(__b, __a);
> +#else
> return __builtin_altivec_vpkswus(__a, __b);
> +#endif
> }
>
> static vector unsigned short __ATTRS_o_ai
> vec_vpkswus(vector unsigned int __a, vector unsigned int __b)
> {
> +#ifdef __LITTLE_ENDIAN__
> + return __builtin_altivec_vpkuwus(__b, __a);
> +#else
> return __builtin_altivec_vpkuwus(__a, __b);
> +#endif
> }
>
> /* vec_perm */
>
>
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--
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory
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