1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "../assembly.h"
// di_int __ashldi3(di_int input, int count);
// This routine has some extra memory traffic, loading the 64-bit input via two
// 32-bit loads, then immediately storing it back to the stack via a single 64-bit
// store. This is to avoid a write-small, read-large stall.
// However, if callers of this routine can be safely assumed to store the argument
// via a 64-bt store, this is unnecessary memory traffic, and should be avoided.
// It can be turned off by defining the TRUST_CALLERS_USE_64_BIT_STORES macro.
#ifdef __i386__
#ifdef __SSE2__
.text
.balign 4
DEFINE_COMPILERRT_FUNCTION(__ashldi3)
movd 12(%esp), %xmm2 // Load count
#ifndef TRUST_CALLERS_USE_64_BIT_STORES
movd 4(%esp), %xmm0
movd 8(%esp), %xmm1
punpckldq %xmm1, %xmm0 // Load input
#else
movq 4(%esp), %xmm0 // Load input
#endif
psllq %xmm2, %xmm0 // shift input by count
movd %xmm0, %eax
psrlq $32, %xmm0
movd %xmm0, %edx
ret
END_COMPILERRT_FUNCTION(__ashldi3)
#else // Use GPRs instead of SSE2 instructions, if they aren't available.
.text
.balign 4
DEFINE_COMPILERRT_FUNCTION(__ashldi3)
movl 12(%esp), %ecx // Load count
movl 8(%esp), %edx // Load high
movl 4(%esp), %eax // Load low
testl $0x20, %ecx // If count >= 32
jnz 1f // goto 1
shldl %cl, %eax, %edx // left shift high by count
shll %cl, %eax // left shift low by count
ret
1: movl %eax, %edx // Move low to high
xorl %eax, %eax // clear low
shll %cl, %edx // shift high by count - 32
ret
END_COMPILERRT_FUNCTION(__ashldi3)
#endif // __SSE2__
#endif // __i386__
NO_EXEC_STACK_DIRECTIVE
|
