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
5 #include "../assembly.h"
7 // di_int __ashldi3(di_int input, int count);
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.
21 DEFINE_COMPILERRT_FUNCTION(__ashldi3)
22 movd 12(%esp), %xmm2 // Load count
23 #ifndef TRUST_CALLERS_USE_64_BIT_STORES
26 punpckldq %xmm1, %xmm0 // Load input
28 movq 4(%esp), %xmm0 // Load input
30 psllq %xmm2, %xmm0 // shift input by count
35 END_COMPILERRT_FUNCTION(__ashldi3)
37 #else // Use GPRs instead of SSE2 instructions, if they aren't available.
41 DEFINE_COMPILERRT_FUNCTION(__ashldi3)
42 movl 12(%esp), %ecx // Load count
43 movl 8(%esp), %edx // Load high
44 movl 4(%esp), %eax // Load low
46 testl $0x20, %ecx // If count >= 32
48 shldl %cl, %eax, %edx // left shift high by count
49 shll %cl, %eax // left shift low by count
52 1: movl %eax, %edx // Move low to high
53 xorl %eax, %eax // clear low
54 shll %cl, %edx // shift high by count - 32
56 END_COMPILERRT_FUNCTION(__ashldi3)
61 NO_EXEC_STACK_DIRECTIVE