1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "asm_support_arm.S" 18 19 .section .text 20 // This function is used to check for the CPU's support for the sdiv 21 // instruction at runtime. It will either return the value 1 or 22 // will cause an invalid instruction trap (SIGILL signal). The 23 // caller must arrange for the signal handler to set the r0 24 // register to 0 and move the pc forward by 4 bytes (to skip 25 // the invalid instruction). 26 ENTRY artCheckForArmSdivInstruction 27 mov r1,#1 28 // depending on the architecture, the assembler will not allow an 29 // sdiv instruction, so we will have to output the bytes directly. 30 31 // sdiv r0,r1,r1 is two words: 0xfb91 0xf1f0. We need little endian. 32 .byte 0x91,0xfb,0xf1,0xf0 33 34 // if the divide worked, r0 will have the value #1 (result of sdiv). 35 // It will have 0 otherwise (set by the signal handler) 36 // the value is just returned from this function. 37 bx lr 38 END artCheckForArmSdivInstruction 39
