https://bugs.llvm.org/show_bug.cgi?id=39473
Bug ID: 39473
Summary: Merge consecutive load insertions into a vector where
possible
Product: libraries
Version: trunk
Hardware: PC
OS: Windows NT
Status: NEW
Severity: enhancement
Priority: P
Component: Common Code Generator Code
Assignee: unassignedb...@nondot.org
Reporter: llvm-...@redking.me.uk
CC: andrea.dibia...@gmail.com, fil...@gmail.com,
llvm-bugs@lists.llvm.org, spatel+l...@rotateright.com
#include <x86intrin.h>
__m128i load_00123456(const unsigned short *data) {
return _mm_setr_epi16(data[0], data[0], data[1], data[2], data[3], data[4],
data[5], data[6]);
}
-O3 -march=btver2
_Z13load_00123456PKt: # @_Z13load_00123456PKt
movzwl (%rdi), %eax
vmovd %eax, %xmm0
vpinsrw $1, %eax, %xmm0, %xmm0
vpinsrw $2, 2(%rdi), %xmm0, %xmm0
vpinsrw $3, 4(%rdi), %xmm0, %xmm0
vpinsrw $4, 6(%rdi), %xmm0, %xmm0
vpinsrw $5, 8(%rdi), %xmm0, %xmm0
vpinsrw $6, 10(%rdi), %xmm0, %xmm0
vpinsrw $7, 12(%rdi), %xmm0, %xmm0
retq
Many of the loads/insertions could be merged to something like:
_Z19load_00123456_mergePKt: # @_Z19load_00123456_mergePKt
movzwl (%rdi), %eax
vmovd %eax, %xmm0
vpshuflw $224, %xmm0, %xmm0 # xmm0 = xmm0[0,0,2,3,4,5,6,7]
vpshufd $0, %xmm0, %xmm0 # xmm0 = xmm0[0,0,0,0]
vpinsrd $1, 2(%rdi), %xmm0, %xmm0
vpinsrq $1, 6(%rdi), %xmm0, %xmm0
retq
https://godbolt.org/z/-HLpsE
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
