1// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 2// See https://llvm.org/LICENSE.txt for license information. 3// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 4 5#include "../assembly.h" 6 7// di_int __ashrdi3(di_int input, int count); 8 9#ifdef __i386__ 10#ifdef __SSE2__ 11 12.text 13.balign 4 14DEFINE_COMPILERRT_FUNCTION(__ashrdi3) 15 movd 12(%esp), %xmm2 // Load count 16 movl 8(%esp), %eax 17#ifndef TRUST_CALLERS_USE_64_BIT_STORES 18 movd 4(%esp), %xmm0 19 movd 8(%esp), %xmm1 20 punpckldq %xmm1, %xmm0 // Load input 21#else 22 movq 4(%esp), %xmm0 // Load input 23#endif 24 25 psrlq %xmm2, %xmm0 // unsigned shift input by count 26 27 testl %eax, %eax // check the sign-bit of the input 28 jns 1f // early out for positive inputs 29 30 // If the input is negative, we need to construct the shifted sign bit 31 // to or into the result, as xmm does not have a signed right shift. 32 pcmpeqb %xmm1, %xmm1 // -1ULL 33 psrlq $58, %xmm1 // 0x3f 34 pandn %xmm1, %xmm2 // 63 - count 35 pcmpeqb %xmm1, %xmm1 // -1ULL 36 psubq %xmm1, %xmm2 // 64 - count 37 psllq %xmm2, %xmm1 // -1 << (64 - count) = leading sign bits 38 por %xmm1, %xmm0 39 40 // Move the result back to the general purpose registers and return 411: movd %xmm0, %eax 42 psrlq $32, %xmm0 43 movd %xmm0, %edx 44 ret 45END_COMPILERRT_FUNCTION(__ashrdi3) 46 47#else // Use GPRs instead of SSE2 instructions, if they aren't available. 48 49.text 50.balign 4 51DEFINE_COMPILERRT_FUNCTION(__ashrdi3) 52 movl 12(%esp), %ecx // Load count 53 movl 8(%esp), %edx // Load high 54 movl 4(%esp), %eax // Load low 55 56 testl $0x20, %ecx // If count >= 32 57 jnz 1f // goto 1 58 59 shrdl %cl, %edx, %eax // right shift low by count 60 sarl %cl, %edx // right shift high by count 61 ret 62 631: movl %edx, %eax // Move high to low 64 sarl $31, %edx // clear high 65 sarl %cl, %eax // shift low by count - 32 66 ret 67END_COMPILERRT_FUNCTION(__ashrdi3) 68 69#endif // __SSE2__ 70#endif // __i386__ 71 72NO_EXEC_STACK_DIRECTIVE 73 74