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Re: Fixed Point (Chapter 13): Clarification Request
perhaps i am not upto date on this topic. but addresses are fixed point. (integers). and you need vector support for vector loads using the vector accumulators.(indexs). the math, other than
perhaps i am not upto date on this topic. but addresses are fixed point. (integers). and you need vector support for vector loads using the vector accumulators.(indexs). the math, other than
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By
swallach
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#327
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Re: Integer Overflow/Saturation Operations
Andy,
Thank you for your response.
The concern I'm raising is less about "How do I avoid overflow?" and more about "Why are we avoiding the specification of saturating instructions, or an overflow
Andy,
Thank you for your response.
The concern I'm raising is less about "How do I avoid overflow?" and more about "Why are we avoiding the specification of saturating instructions, or an overflow
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By
CDS <cohen.steed@...>
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#326
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Re: Fixed Point (Chapter 13): Clarification Request
Perhaps, it is important to understand the history of why fixed point is utilized. Historically, fixed point was the alternative for expensive floating point implementations/operations, or was the
Perhaps, it is important to understand the history of why fixed point is utilized. Historically, fixed point was the alternative for expensive floating point implementations/operations, or was the
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By
CDS <cohen.steed@...>
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#325
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Edited
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Re: Fixed Point (Chapter 13): Clarification Request
| Thank you for the response, Andrew.
| Given that these operations are intended to be conveniences, in the first place (hence: vector), the
| addition of a required macro for inclusion could be
| Thank you for the response, Andrew.
| Given that these operations are intended to be conveniences, in the first place (hence: vector), the
| addition of a required macro for inclusion could be
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By
Krste Asanovic
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#324
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Vector TG minutes for 2020/8/7 meeting
Date: 2020/8/7
Task Group: Vector Extension
Chair: Krste Asanovic
Co-Chair: Roger Espasa
Number of Attendees: ~22
Current issues on github: https://github.com/riscv/riscv-v-spec
Issues
Date: 2020/8/7
Task Group: Vector Extension
Chair: Krste Asanovic
Co-Chair: Roger Espasa
Number of Attendees: ~22
Current issues on github: https://github.com/riscv/riscv-v-spec
Issues
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By
Krste Asanovic
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#323
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Vector TG meeting minutes 2020/7/31 meeting
Apologies for delay in sending these out. When doing this week's
minutes, I realized I hadn't sent out previous week's.
Krste
Date: 2020/7/31
Task Group: Vector Extension
Chair: Krste
Apologies for delay in sending these out. When doing this week's
minutes, I realized I hadn't sent out previous week's.
Krste
Date: 2020/7/31
Task Group: Vector Extension
Chair: Krste
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By
Krste Asanovic
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#322
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Re: Integer Overflow/Saturation Operations
For extended precision arithmetic, e.g. such as is often performed in cryptography, 2X widening multiply accumulate is the best that I have found. (And as far as I know other members
For extended precision arithmetic, e.g. such as is often performed in cryptography, 2X widening multiply accumulate is the best that I have found. (And as far as I know other members
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By
Andy Glew Si5
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#321
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Re: Fixed Point (Chapter 13): Clarification Request
Thank you for the response, Andrew.
Given that these operations are intended to be conveniences, in the first place (hence: vector), the addition of a required macro for inclusion could be considered
Thank you for the response, Andrew.
Given that these operations are intended to be conveniences, in the first place (hence: vector), the addition of a required macro for inclusion could be considered
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By
CDS <cohen.steed@...>
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#320
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Re: Fixed Point (Chapter 13): Clarification Request
Having implemented these instructions recently, I can say they weren’t unduly onerous to provide, and the HW cost increase wasn’t that great (the rounding and clipping logic are new; the rest
Having implemented these instructions recently, I can say they weren’t unduly onerous to provide, and the HW cost increase wasn’t that great (the rounding and clipping logic are new; the rest
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By
andrew@...
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#319
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Re: vrsub.vi, used as negation
Would be mostly redundant with vadd.vi, since the immediate operand is signed. (Same reason the scalar ISA doesn’t provide a subi instruction.)
Would be mostly redundant with vadd.vi, since the immediate operand is signed. (Same reason the scalar ISA doesn’t provide a subi instruction.)
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By
andrew@...
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#318
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vrsub.vi, used as negation
Is the point of vrsub.vi to provide negation? From a compiler/user perspective, completing the vsub pattern with vsub.vi (even as a virtual instruction) may be a usability enhancement to consider.
Is the point of vrsub.vi to provide negation? From a compiler/user perspective, completing the vsub pattern with vsub.vi (even as a virtual instruction) may be a usability enhancement to consider.
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By
CDS <cohen.steed@...>
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#317
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Integer Overflow/Saturation Operations
Vector-widening multiply & accumulate instructions:
These instructions, signed or unsigned, will quickly overflow in even simple cases.
Given absence of flagging (e.g. OVERFLOW), a saturating version
Vector-widening multiply & accumulate instructions:
These instructions, signed or unsigned, will quickly overflow in even simple cases.
Given absence of flagging (e.g. OVERFLOW), a saturating version
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By
CDS <cohen.steed@...>
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#316
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Fixed Point (Chapter 13): Clarification Request
The definition of the numeric range (at the beginning of section 13) matches the definition of an integer, not of a fixed-point number. For example, the range specified is the range of an integer,
The definition of the numeric range (at the beginning of section 13) matches the definition of an integer, not of a fixed-point number. For example, the range specified is the range of an integer,
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By
CDS <cohen.steed@...>
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#315
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Re: [riscv/riscv-v-spec] For V1.0 - Make unsigned scalar integer in widening instructions 2 * SEW (#427) (and signed)
great!
again this is meant as informational for when this goes to vote.
this should be discussable now in email with questions and comments.
please include this in the ratification materials (place in
great!
again this is meant as informational for when this goes to vote.
this should be discussable now in email with questions and comments.
please include this in the ratification materials (place in
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By
mark
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#314
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Re: [riscv/riscv-v-spec] For V1.0 - Make unsigned scalar integer in widening instructions 2 * SEW (#427) (and signed)
I filled out the RISC-V Policy: Change and Extension Rationale
as best I could for the issue #427. I believe it is accessible by all. But I will also paste the contents below.
I filled out the RISC-V Policy: Change and Extension Rationale
as best I could for the issue #427. I believe it is accessible by all. But I will also paste the contents below.
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By
David Horner
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#313
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Proposed WG: RISC V needs CMOs, and hence a CMO Working Group
RISC V needs CMOs, and hence a CMO Working Group
EditNew Page
RISC V needs CMOs, and hence a CMO Working Group
EditNew Page
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By
Andy Glew Si5
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#312
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[riscv/riscv-v-spec] For V1.0 - Make unsigned scalar integer in widening instructions 2 * SEW (#427) (and signed)
I posted a comment to the closed #427
Not everyone subscribes to GitHub, so I post it below,
I am requesting this proposal be reconsidered/re-evaluated for V1.0 inclusion in
I posted a comment to the closed #427
Not everyone subscribes to GitHub, so I post it below,
I am requesting this proposal be reconsidered/re-evaluated for V1.0 inclusion in
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By
David Horner
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#311
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Re: VFRECIP/VFRSQRT instructions
On 8/3/20 1:41 PM, Andrew Waterman wrote:
I agree with your computation with a really tiny difference (I get that it just barely rounds to 2^-7.32040). I can't say why I got 37 when I did it 8-10
On 8/3/20 1:41 PM, Andrew Waterman wrote:
I agree with your computation with a really tiny difference (I get that it just barely rounds to 2^-7.32040). I can't say why I got 37 when I did it 8-10
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By
Bill Huffman
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#310
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Re: VFRECIP/VFRSQRT instructions
Thanks for validating against your table, Bill.
With my value for that entry, the worst error on the interval of interest is 2^-7.32041, for input 0x3f1a0000. With yours, it's 2^-7.3164 for
Thanks for validating against your table, Bill.
With my value for that entry, the worst error on the interval of interest is 2^-7.32041, for input 0x3f1a0000. With yours, it's 2^-7.3164 for
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By
andrew@...
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#309
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Re: VFRECIP/VFRSQRT instructions
The recip table matches mine as does the worst case error.
I have one different entry in the square root table. For entry 77, where you have 36, I have 37. I'm not sure whether it matters. Also,
The recip table matches mine as does the worst case error.
I have one different entry in the square root table. For entry 77, where you have 36, I have 37. I'm not sure whether it matters. Also,
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By
Bill Huffman
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#308
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