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 __ashldi3(di_int input, int count);
8
9// This routine has some extra memory traffic, loading the 64-bit input via two
10// 32-bit loads, then immediately storing it back to the stack via a single 64-bit
11// store. This is to avoid a write-small, read-large stall.
12// However, if callers of this routine can be safely assumed to store the argument
13// via a 64-bt store, this is unnecessary memory traffic, and should be avoided.
14// It can be turned off by defining the TRUST_CALLERS_USE_64_BIT_STORES macro.
15
16#ifdef __i386__
17#ifdef __SSE2__
18
19.text
20.balign 4
21DEFINE_COMPILERRT_FUNCTION(__ashldi3)
22 movd 12(%esp), %xmm2 // Load count
23#ifndef TRUST_CALLERS_USE_64_BIT_STORES
24 movd 4(%esp), %xmm0
25 movd 8(%esp), %xmm1
26 punpckldq %xmm1, %xmm0 // Load input
27#else
28 movq 4(%esp), %xmm0 // Load input
29#endif
30 psllq %xmm2, %xmm0 // shift input by count
31 movd %xmm0, %eax
32 psrlq $32, %xmm0
33 movd %xmm0, %edx
34 ret
35END_COMPILERRT_FUNCTION(__ashldi3)
36
37#else // Use GPRs instead of SSE2 instructions, if they aren't available.
38
39.text
40.balign 4
41DEFINE_COMPILERRT_FUNCTION(__ashldi3)
42 movl 12(%esp), %ecx // Load count
43 movl 8(%esp), %edx // Load high
44 movl 4(%esp), %eax // Load low
45
46 testl $0x20, %ecx // If count >= 32
47 jnz 1f // goto 1
48 shldl %cl, %eax, %edx // left shift high by count
49 shll %cl, %eax // left shift low by count
50 ret
51
521: movl %eax, %edx // Move low to high
53 xorl %eax, %eax // clear low
54 shll %cl, %edx // shift high by count - 32
55 ret
56END_COMPILERRT_FUNCTION(__ashldi3)
57
58#endif // __SSE2__
59#endif // __i386__
60
61NO_EXEC_STACK_DIRECTIVE
62
63

source code of compiler-rt/lib/builtins/i386/ashldi3.S