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/*
* Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
/** @file
*
* Mathematical self-tests
*
*/
/* Forcibly enable assertions */
#undef NDEBUG
#include <string.h>
#include <strings.h>
#include <assert.h>
#include <ipxe/test.h>
#include <ipxe/isqrt.h>
/**
* Force a call to the non-constant implementation of flsl()
*
* @v value Value
* @ret msb Most significant bit set in value (LSB=1), or zero
*/
__attribute__ (( noinline )) int flsl_var ( long value ) {
return flsl ( value );
}
/**
* Force a call to the non-constant implementation of flsll()
*
* @v value Value
* @ret msb Most significant bit set in value (LSB=1), or zero
*/
__attribute__ (( noinline )) int flsll_var ( long long value ) {
return flsll ( value );
}
/**
* Check current stack pointer
*
* @ret stack A value at a fixed offset from the current stack pointer
*
* Used by check_divmod()
*/
static __attribute__ (( noinline )) void * stack_check ( void ) {
int a;
void *ret;
/* Hide the fact that we are returning the address of a local
* variable, to prevent a compiler warning.
*/
__asm__ ( "\n" : "=g" ( ret ) : "0" ( &a ) );
return ret;
}
/**
* Check division/modulus operation
*
* One aspect of the calling convention for the implicit arithmetic
* functions (__udivmoddi4() etc) is whether the caller or the callee
* is expected to pop any stack-based arguments. This distinction can
* be masked if the compiler chooses to uses a frame pointer in the
* caller, since the caller will then reload the stack pointer from
* the frame pointer and so can mask an error in the value of the
* stack pointer.
*
* We run the division operation in a loop, and check that the stack
* pointer does not change value on the second iteration. To prevent
* the compiler from performing various optimisations which might
* invalidate our intended test (such as unrolling the loop, or moving
* the division operation outside the loop), we include some dummy
* inline assembly code.
*/
#define check_divmod( dividend, divisor, OP ) ( { \
uint64_t result; \
int count = 2; \
void *check = NULL; \
\
/* Prevent compiler from unrolling the loop */ \
__asm__ ( "\n" : "=g" ( count ) : "0" ( count ) ); \
\
do { \
/* Check that stack pointer does not change between \
* loop iterations. \
*/ \
if ( check ) { \
assert ( check == stack_check() ); \
} else { \
check = stack_check(); \
} \
\
/* Perform division, preventing the compiler from \
* moving the division out of the loop. \
*/ \
__asm__ ( "\n" : "=g" ( dividend ), "=g" ( divisor ) \
: "0" ( dividend ), "1" ( divisor ) ); \
result = ( dividend OP divisor ); \
__asm__ ( "\n" : "=g" ( result ) : "0" ( result ) ); \
\
} while ( --count ); \
result; } )
/**
* Force a use of runtime 64-bit unsigned integer division
*
* @v dividend Dividend
* @v divisor Divisor
* @ret quotient Quotient
*/
__attribute__ (( noinline )) uint64_t u64div_var ( uint64_t dividend,
uint64_t divisor ) {
return check_divmod ( dividend, divisor, / );
}
/**
* Force a use of runtime 64-bit unsigned integer modulus
*
* @v dividend Dividend
* @v divisor Divisor
* @ret remainder Remainder
*/
__attribute__ (( noinline )) uint64_t u64mod_var ( uint64_t dividend,
uint64_t divisor ) {
return check_divmod ( dividend, divisor, % );
}
/**
* Force a use of runtime 64-bit signed integer division
*
* @v dividend Dividend
* @v divisor Divisor
* @ret quotient Quotient
*/
__attribute__ (( noinline )) int64_t s64div_var ( int64_t dividend,
int64_t divisor ) {
return check_divmod ( dividend, divisor, / );
}
/**
* Force a use of runtime 64-bit unsigned integer modulus
*
* @v dividend Dividend
* @v divisor Divisor
* @ret remainder Remainder
*/
__attribute__ (( noinline )) int64_t s64mod_var ( int64_t dividend,
int64_t divisor ) {
return check_divmod ( dividend, divisor, % );
}
/**
* Report a flsl() test result
*
* @v value Value
* @v msb Expected MSB
* @v file Test code file
* @v line Test code line
*/
static inline __attribute__ (( always_inline )) void
flsl_okx ( long value, int msb, const char *file, unsigned int line ) {
/* Verify as a constant (requires to be inlined) */
okx ( flsl ( value ) == msb, file, line );
/* Verify as a non-constant */
okx ( flsl_var ( value ) == msb, file, line );
}
#define flsl_ok( value, msb ) flsl_okx ( value, msb, __FILE__, __LINE__ )
/**
* Report a flsll() test result
*
* @v value Value
* @v msb Expected MSB
* @v file Test code file
* @v line Test code line
*/
static inline __attribute__ (( always_inline )) void
flsll_okx ( long long value, int msb, const char *file, unsigned int line ) {
/* Verify as a constant (requires to be inlined) */
okx ( flsll ( value ) == msb, file, line );
/* Verify as a non-constant */
okx ( flsll_var ( value ) == msb, file, line );
}
#define flsll_ok( value, msb ) flsll_okx ( value, msb, __FILE__, __LINE__ )
/**
* Report a 64-bit unsigned integer division test result
*
* @v dividend Dividend
* @v divisor Divisor
* @v quotient Quotient
* @v remainder Remainder
* @v file Test code file
* @v line Test code line
*/
static void u64divmod_okx ( uint64_t dividend, uint64_t divisor,
uint64_t quotient, uint64_t remainder,
const char *file, unsigned int line ) {
/* Sanity check */
okx ( ( ( divisor * quotient ) + remainder ) == dividend, file, line );
/* Check division */
okx ( u64div_var ( dividend, divisor ) == quotient, file, line );
/* Check modulus */
okx ( u64mod_var ( dividend, divisor ) == remainder, file, line );
}
#define u64divmod_ok( dividend, divisor, quotient, remainder ) \
u64divmod_okx ( dividend, divisor, quotient, remainder, \
__FILE__, __LINE__ )
/**
* Report a 64-bit signed integer division test result
*
* @v dividend Dividend
* @v divisor Divisor
* @v quotient Quotient
* @v remainder Remainder
* @v file Test code file
* @v line Test code line
*/
static void s64divmod_okx ( int64_t dividend, int64_t divisor,
int64_t quotient, int64_t remainder,
const char *file, unsigned int line ) {
/* Sanity check */
okx ( ( ( divisor * quotient ) + remainder ) == dividend, file, line );
/* Check division */
okx ( s64div_var ( dividend, divisor ) == quotient, file, line );
/* Check modulus */
okx ( s64mod_var ( dividend, divisor ) == remainder, file, line );
}
#define s64divmod_ok( dividend, divisor, quotient, remainder ) \
s64divmod_okx ( dividend, divisor, quotient, remainder, \
__FILE__, __LINE__ )
/**
* Perform mathematical self-tests
*
*/
static void math_test_exec ( void ) {
/* Test flsl() */
flsl_ok ( 0, 0 );
flsl_ok ( 1, 1 );
flsl_ok ( 255, 8 );
flsl_ok ( 256, 9 );
flsl_ok ( 257, 9 );
flsl_ok ( 0x69505845, 31 );
flsl_ok ( -1U, ( 8 * sizeof ( int ) ) );
flsl_ok ( -1UL, ( 8 * sizeof ( long ) ) );
/* Test flsll() */
flsll_ok ( 0, 0 );
flsll_ok ( 1, 1 );
flsll_ok ( 0x6d63623330ULL, 39 );
flsll_ok ( -1U, ( 8 * sizeof ( int ) ) );
flsll_ok ( -1UL, ( 8 * sizeof ( long ) ) );
flsll_ok ( -1ULL, ( 8 * sizeof ( long long ) ) );
/* Test 64-bit arithmetic
*
* On a 64-bit machine, these tests are fairly meaningless.
*
* On a 32-bit machine, these tests verify the correct
* operation of our libgcc functions __udivmoddi4()
* etc. (including checking that the implicit calling
* convention assumed by gcc matches our expectations).
*/
u64divmod_ok ( 0x2b90ddccf699f765ULL, 0xed9f5e73ULL,
0x2eef6ab4ULL, 0x0e12f089ULL );
s64divmod_ok ( 0x2b90ddccf699f765ULL, 0xed9f5e73ULL,
0x2eef6ab4ULL, 0x0e12f089ULL );
u64divmod_ok ( 0xc09e00dcb9e34b54ULL, 0x35968185cdc744f3ULL,
3, 0x1fda7c4b508d7c7bULL );
s64divmod_ok ( -0x3f61ff23461cb4acLL, 0x35968185cdc744f3ULL,
-1LL, -0x9cb7d9d78556fb9LL );
u64divmod_ok ( 0, 0x5b2f2737f4ffULL, 0, 0 );
s64divmod_ok ( 0, 0xbb00ded72766207fULL, 0, 0 );
/* Test integer square root */
ok ( isqrt ( 0 ) == 0 );
ok ( isqrt ( 1 ) == 1 );
ok ( isqrt ( 255 ) == 15 );
ok ( isqrt ( 256 ) == 16 );
ok ( isqrt ( 257 ) == 16 );
ok ( isqrt ( 0xa53df2adUL ) == 52652 );
ok ( isqrt ( 0x123793c6UL ) == 17482 );
ok ( isqrt ( -1UL ) == ( -1UL >> ( 8 * sizeof ( unsigned long ) / 2 )));
}
/** Mathematical self-tests */
struct self_test math_test __self_test = {
.name = "math",
.exec = math_test_exec,
};
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