Re: [libav-devel] [PATCH 0/3] support for FMA3 and BMI intruction sets
On 22/02/14 06:53, James Almer wrote: These are the missing instruction sets introduced with Haswell/Piledriver CPUs. Last two patches are based on x264 detection code. The set doesn't look bad at all but I'm wondering about it's usage: James Almer (3): x86: add missing XOP checks and macros x86: add detection for FMA3 instruction set Which is the relationship between FMA3 and FMA4 ? x86: add detection for Bit Manipulation Instruction sets Is BMI a subset of AVX2? lu ___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
Re: [libav-devel] [PATCH 0/3] support for FMA3 and BMI intruction sets
On 22/02/14 1:29 PM, Luca Barbato wrote: On 22/02/14 06:53, James Almer wrote: These are the missing instruction sets introduced with Haswell/Piledriver CPUs. Last two patches are based on x264 detection code. The set doesn't look bad at all but I'm wondering about it's usage: James Almer (3): x86: add missing XOP checks and macros x86: add detection for FMA3 instruction set Which is the relationship between FMA3 and FMA4 ? It's what happens when Intel and AMD don't talk to each other to coordinate stuff. Short story summary here: https://en.wikipedia.org/wiki/FMA_instruction_set Both sets do the same in essence. The only difference is that one uses three operands while the other uses four (Technically, FMA4 is the most flexible, but it's only supported by AMD). AMD added FMA4 starting with Bulldozer, then added FMA3 as well to Piledriver for compatibility reasons once Intel revealed they would use that starting with Haswell. x86: add detection for Bit Manipulation Instruction sets Is BMI a subset of AVX2? No, they are independent and work on general registers. AMD added BMI1 starting with Piledriver, which doesn't support AVX2, whereas Intel added both BMI1 and BMI2 starting with Haswell. lu ___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel ___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
Re: [libav-devel] [PATCH 0/3] support for FMA3 and BMI intruction sets
On 22/02/14 17:42, James Almer wrote: On 22/02/14 1:29 PM, Luca Barbato wrote: On 22/02/14 06:53, James Almer wrote: These are the missing instruction sets introduced with Haswell/Piledriver CPUs. Last two patches are based on x264 detection code. The set doesn't look bad at all but I'm wondering about it's usage: James Almer (3): x86: add missing XOP checks and macros x86: add detection for FMA3 instruction set Which is the relationship between FMA3 and FMA4 ? It's what happens when Intel and AMD don't talk to each other to coordinate stuff. Short story summary here: https://en.wikipedia.org/wiki/FMA_instruction_set Both sets do the same in essence. The only difference is that one uses three operands while the other uses four (Technically, FMA4 is the most flexible, but it's only supported by AMD). AMD added FMA4 starting with Bulldozer, then added FMA3 as well to Piledriver for compatibility reasons once Intel revealed they would use that starting with Haswell. x86: add detection for Bit Manipulation Instruction sets Is BMI a subset of AVX2? No, they are independent and work on general registers. AMD added BMI1 starting with Piledriver, which doesn't support AVX2, whereas Intel added both BMI1 and BMI2 starting with Haswell. So complex as usual... I'd let another day pass (hoping somebody else reads those and push them. lu ___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
[libav-devel] [PATCH 0/3] support for FMA3 and BMI intruction sets
These are the missing instruction sets introduced with Haswell/Piledriver CPUs. Last two patches are based on x264 detection code. James Almer (3): x86: add missing XOP checks and macros x86: add detection for FMA3 instruction set x86: add detection for Bit Manipulation Instruction sets configure | 10 ++ libavutil/cpu.c | 9 + libavutil/cpu.h | 3 +++ libavutil/x86/cpu.c | 21 +++-- libavutil/x86/cpu.h | 6 ++ 5 files changed, 43 insertions(+), 6 deletions(-) -- 1.8.3.2 ___ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
