Invention Grant
- Patent Title: Double rounded combined floating-point multiply and add
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Application No.: US15332721Application Date: 2016-10-24
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Publication No.: US09778909B2Publication Date: 2017-10-03
- Inventor: Sridhar Samudrala , Grigorios Magklis , Marc Lupon , David R. Ditzel
- Applicant: Intel Corporation
- Applicant Address: US CA Santa Clara
- Assignee: Intel Corporation
- Current Assignee: Intel Corporation
- Current Assignee Address: US CA Santa Clara
- Agency: Lowenstein Sandler LLP
- Main IPC: G06F7/38
- IPC: G06F7/38 ; G06F7/487 ; G06F7/483 ; G06F7/544 ; G06F7/485 ; G06F7/499

Abstract:
Methods, apparatus, instructions and logic are disclosed providing double rounded combined floating-point multiply and add functionality as scalar or vector SIMD instructions or as fused micro-operations. Embodiments include detecting floating-point (FP) multiplication operations and subsequent FP operations specifying as source operands results of the FP multiplications. The FP multiplications and the subsequent FP operations are encoded as combined FP operations including rounding of the results of FP multiplication followed by the subsequent FP operations. The encoding of said combined FP operations may be stored and executed as part of an executable thread portion using fused-multiply-add hardware that includes overflow detection for the product of FP multipliers, first and second FP adders to add third operand addend mantissas and the products of the FP multipliers with different rounding inputs based on overflow, or no overflow, in the products of the FP multiplier. Final results are selected respectively using overflow detection.
Public/Granted literature
- US20170039033A1 DOUBLE ROUNDED COMBINED FLOATING-POINT MULTIPLY AND ADD Public/Granted day:2017-02-09
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