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/* Copyright 2018 The ChromiumOS Authors
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Enable the use of right shift for uint64_t. */
#include <stdint.h>
#include <compile_time_macros.h>
#include <console.h>
union words {
uint64_t u64;
uint32_t w[2];
};
uint64_t __keep __aeabi_llsr(uint64_t v, uint32_t shift)
{
union words val;
union words res;
val.u64 = v;
res.w[1] = val.w[1] >> shift;
res.w[0] = val.w[0] >> shift;
res.w[0] |= val.w[1] >> (shift - 32); /* Handle shift >= 32*/
res.w[0] |= val.w[1] << (32 - shift); /* Handle shift <= 32*/
return res.u64;
}
#ifdef CONFIG_LLSR_TEST
static int command_llsr(int argc, const char **argv)
{
/* Volatile to prevent compilier optimization from interfering. */
volatile uint64_t start = 0x123456789ABCDEF0ull;
uint32_t x;
const struct {
uint32_t shift_by;
uint64_t result;
} cases[] = { { 0, start },
{ 16, 0x123456789ABCull },
{ 32, 0x12345678u },
{ 48, 0x1234u },
{ 64, 0u } };
for (x = 0; x < ARRAY_SIZE(cases); ++x) {
if ((start >> cases[x].shift_by) != cases[x].result) {
ccprintf("FAILED %d\n", cases[x].shift_by);
return EC_ERROR_UNKNOWN;
}
}
ccprintf("SUCCESS\n");
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(
llsrtest, command_llsr, "",
"Run tests against the LLSR ABI. Prints SUCCESS or FAILURE.");
#endif /* CONFIG_LLSR_TEST */
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