http://software.intel.com/en-us/articles/prototype-primitives-guide/feed/ en-us http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-21942 Mon, 30 Mar 2009 07:46:10 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-21942 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-22222 Sun, 05 Apr 2009 21:27:51 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-22222 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-22377 Wed, 08 Apr 2009 21:35:18 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-22377 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-22416 Thu, 09 Apr 2009 15:01:32 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-22416 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23018 Wed, 22 Apr 2009 06:35:59 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23018 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23086 Thu, 23 Apr 2009 08:55:18 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23086 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23295 Mon, 27 Apr 2009 05:42:29 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23295 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23669 Mon, 04 May 2009 22:42:42 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23669 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23694 Tue, 05 May 2009 06:23:01 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23694 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23862 Thu, 07 May 2009 01:21:39 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-23862 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24343 Wed, 13 May 2009 23:57:15 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24343 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24406 Fri, 15 May 2009 08:48:57 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24406 I think there's a bug in the implementation of _mm512_mask_shuf128x32: wordPerm needs to be right >shifted every inner-loop iteration irrespective of the write-mask. At present, it's only right shifted if the >write-mask bit for that element is set. You are very correct, thank you for finding this bug! We will post a new version of the library with this and other issues fixed soon. > When you compile with gcc, I recommend to add the following in the header: #elif defined(__GNUC__) typedef struct { float v[16]; } __attribute__((__may_alias__)) __m512; typedef struct { double v[8]; } __attribute__((__may_alias__)) __m512d; typedef struct { int v[16]; } __attribute__((__may_alias__)) __m512i; >This allows you to cast between the different __m512 types which is often necessary to use the >load/store/gather/scatter intrinsics. Thank you. The library does provide functions _mm512_cast*_*() to cast between the different types, however you have provided a better solution for gcc. This will be added to the new version of the library which will be posted soon. > Actually it seems that the prototype header is making so much use of aliasing, which is not allowed >according to ISO, that you have to compile with -fno-strict-aliasing when using gcc. Expect undefined >results if you don't. Thank you, you are correct. As suggested by another user, we will mark the __m512 types with __attribute__((__may_alias__)) to make casting easier in gcc. > The *_pd math utility operations in the prototype header all try to operate on 16 doubles. Gave me >some curious crashes. If you want to try doubles with this header better replace all the 16s in the _pd >functions with an 8... :-) Thank you for finding this large class of embarrassing cut and paste bugs! We will post a new version of the library with this and other issues fixed soon. -Chris ]]> http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24408 Fri, 15 May 2009 09:02:54 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24408 I'm wondering how fast the vector cmp operation is?... Does it compare two vec's in a single >instruction pass? Correct. > i'm wondering which of the following operations are implemented as full precision and/or partial->precision estimates .. > > div_ps > recipsqrt_ps > recip_ps > sqrt_ps > log2_ps > exp2_ps The answer is complex, and it depends on the hardware you’re running on and which compiler options you choose, but the one-line answer is that for high-performance code you will usually get around 20 bits of precision or more. So not full precision, but not too far off. Higher-precision variants will also be available where needed. > what is going to be the approximate clock cycle of these instructions ? Most of them are one instruction per clock, though a few are longer. Some more details on performance are available in the GDC 2009 talks. ]]> http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24409 Fri, 15 May 2009 09:06:06 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24409 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24463 Sun, 17 May 2009 10:01:45 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24463 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24508 Mon, 18 May 2009 13:34:27 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-24508 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-25941 Thu, 11 Jun 2009 11:17:10 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-25941 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-25946 Thu, 11 Jun 2009 13:22:43 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-25946 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-27352 Thu, 09 Jul 2009 09:07:57 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-27352 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-28746 Thu, 30 Jul 2009 03:27:04 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-28746 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-28966 Mon, 03 Aug 2009 15:45:23 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-28966 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-29729 Mon, 17 Aug 2009 11:11:17 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-29729 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-33505 Thu, 29 Oct 2009 07:26:57 -0700 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-33505 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-33832 Mon, 02 Nov 2009 16:45:01 -0800 http://software.intel.com/en-us/articles/prototype-primitives-guide/#comment-33832