nuttx/arch/x86_64/src/intel64/intel64_fpucmp.c
p-szafonimateusz 3a3341ba0e arch/intel64: enable FPU and implement up_fpucmp to pass ostest
enable FPU and implement up_fpucmp to pass ostest

With aggressive optimization enabled (-O2/-O3), ostest FPU test will fail.
This is because the compiler will generate additional vector
instructions between subsequent up_fpucmp() calls (loop vectorization
somewhere in usleep() call), which will consequently overwrite
the expected FPU context (XMM registers).

Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
2024-02-26 18:17:37 -03:00

77 lines
2.7 KiB
C

/****************************************************************************
* arch/x86_64/src/intel64/intel64_fpucmp.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <string.h>
#include <nuttx/irq.h>
#include "x86_64_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifdef CONFIG_ARCH_FPU
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_fpucmp
*
* Description:
* Compare FPU areas from thread context.
*
* Input Parameters:
* saveregs1 - Pointer to the saved FPU registers.
* saveregs2 - Pointer to the saved FPU registers.
*
* Returned Value:
* True if FPU areas compare equal, False otherwise.
*
****************************************************************************/
bool up_fpucmp(const void *saveregs1, const void *saveregs2)
{
const uint32_t *regs1 = saveregs1;
const uint32_t *regs2 = saveregs2;
/* IMPORTANT:
*
* With aggresive optimization enabled (-O2/-O3), ostest FPU test will
* fail. This is because the compiler will generate additional vector
* instructions between subsequent up_fpucmp() calls (loop vectorization
* somewhere in usleep() call), which will consequently overwrite
* the expected FPU context (XMM registers).
*/
/* XMM area starts from offset 0 */
return memcmp(&regs1[0], &regs2[0], XCPTCONTEXT_XMM_AREA_SIZE) == 0;
}
#endif /* CONFIG_ARCH_FPU */