diff options
| author | Shawn Nematbakhsh <shawnn@chromium.org> | 2017-06-15 15:07:35 -0700 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2017-06-19 15:33:09 -0700 |
| commit | 90167c1764ab7c532b121bd08990b81631a3c896 (patch) | |
| tree | cb2b1dadc7052437d071b872b6aff04df221d0d8 /core/cortex-m0 | |
| parent | 0696dd1e68692ca8dae17b737e0d895561f65cd4 (diff) | |
| download | chrome-ec-90167c1764ab7c532b121bd08990b81631a3c896.tar.gz | |
math_util: Use HW instruction for int_sqrtf when available
Cortex-M4 supports a floating point square root function that takes 14
cycles to execute, which is a speed improvement over the existing binary
search, and saves flash space.
BUG=chromium:687624
BRANCH=None
TEST=On kevin, verify that both sqrtf methods (binary search vs HW
instruction) have identical results for fractional input (eg.
sqrt(15.999999) = 3), except when floating point representation of
square root rounds up to an integer. Verify identical results for all
integers [-100, 16793602). Note that 16793602 is the first integer for
which the floating point representation of sqrt rounds up to an integer.
Also verify basic motion sense functions on kevin.
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Change-Id: I8521c9a28c958b340ca83c37342253e424df0c91
Reviewed-on: https://chromium-review.googlesource.com/537734
Commit-Ready: Shawn N <shawnn@chromium.org>
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Shawn N <shawnn@chromium.org>
Diffstat (limited to 'core/cortex-m0')
| -rw-r--r-- | core/cortex-m0/include/math.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/core/cortex-m0/include/math.h b/core/cortex-m0/include/math.h new file mode 100644 index 0000000000..4c8955e74d --- /dev/null +++ b/core/cortex-m0/include/math.h @@ -0,0 +1,11 @@ +/* Copyright 2017 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +/* Math utility functions for ARMv6-M */ + +#ifndef __CROS_EC_MATH_H +#define __CROS_EC_MATH_H + +#endif /* __CROS_EC_MATH_H */ |