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b7f513803b
While working on the CTM implementation of VKMS I had to ascertain myself of a few assumptions. One of those is whether drm_fixed.h treats its numbers using signed-magnitude or twos-complement. It is twos-complement. In order to make someone else's day easier I am adding the drm_test_int2fixp test that validates the above assumption. I am also adding a test for the new sm2fixp function that converts from a signed-magnitude fixed point to the twos-complement fixed point. Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com> Signed-off-by: Alex Hung <alex.hung@amd.com> Signed-off-by: Harry Wentland <harry.wentland@amd.com> Reviewed-by: Daniel Stone <daniels@collabora.com> Signed-off-by: Simon Ser <contact@emersion.fr> Link: https://patch.msgid.link/20251115000237.3561250-22-alex.hung@amd.com
72 lines
1.8 KiB
C
72 lines
1.8 KiB
C
// SPDX-License-Identifier: MIT
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/*
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* Copyright 2022 Advanced Micro Devices, Inc.
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*/
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#include <kunit/test.h>
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#include <drm/drm_fixed.h>
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static void drm_test_sm2fixp(struct kunit *test)
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{
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KUNIT_EXPECT_EQ(test, 0x7fffffffffffffffll, ((1ull << 63) - 1));
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/* 1 */
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KUNIT_EXPECT_EQ(test, drm_int2fixp(1), drm_sm2fixp(1ull << DRM_FIXED_POINT));
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/* -1 */
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KUNIT_EXPECT_EQ(test, drm_int2fixp(-1),
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drm_sm2fixp((1ull << 63) | (1ull << DRM_FIXED_POINT)));
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/* 0.5 */
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KUNIT_EXPECT_EQ(test, drm_fixp_from_fraction(1, 2),
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drm_sm2fixp(1ull << (DRM_FIXED_POINT - 1)));
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/* -0.5 */
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KUNIT_EXPECT_EQ(test, drm_fixp_from_fraction(-1, 2),
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drm_sm2fixp((1ull << 63) | (1ull << (DRM_FIXED_POINT - 1))));
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}
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static void drm_test_int2fixp(struct kunit *test)
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{
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/* 1 */
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KUNIT_EXPECT_EQ(test, 1ll << 32, drm_int2fixp(1));
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/* -1 */
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KUNIT_EXPECT_EQ(test, -(1ll << 32), drm_int2fixp(-1));
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/* 1 + (-1) = 0 */
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KUNIT_EXPECT_EQ(test, 0, drm_int2fixp(1) + drm_int2fixp(-1));
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/* 1 / 2 */
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KUNIT_EXPECT_EQ(test, 1ll << 31, drm_fixp_from_fraction(1, 2));
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/* -0.5 */
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KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(-1, 2));
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/* (1 / 2) + (-1) = 0.5 */
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KUNIT_EXPECT_EQ(test, 1ll << 31, drm_fixp_from_fraction(-1, 2) + drm_int2fixp(1));
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/* (1 / 2) - 1) = 0.5 */
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KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(1, 2) + drm_int2fixp(-1));
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/* (1 / 2) - 1) = 0.5 */
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KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(1, 2) - drm_int2fixp(1));
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}
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static struct kunit_case drm_fixp_tests[] = {
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KUNIT_CASE(drm_test_int2fixp),
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KUNIT_CASE(drm_test_sm2fixp),
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{ }
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};
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static struct kunit_suite drm_fixp_test_suite = {
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.name = "drm_fixp",
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.test_cases = drm_fixp_tests,
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};
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kunit_test_suite(drm_fixp_test_suite);
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MODULE_AUTHOR("AMD");
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MODULE_LICENSE("Dual MIT/GPL");
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MODULE_DESCRIPTION("Unit tests for drm_fixed.h");
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