Imported Upstream version 2.1.0upstream/2.1.0

1 files changed, 326 insertions, 0 deletions

diff --git a/roms/ipxe/src/tests/math_test.c b/roms/ipxe/src/tests/math_test.c
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+++ b/roms/ipxe/src/tests/math_test.c
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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,
+};