Redundant bound checks for arr[^N-1] after arr[^N] #124531
Description
public int DecodeRemaining(ReadOnlySpan<int> source)
=> source[^4] | source[^3] | source[^2] | source[^1];currently generates:
; Method Program:DecodeRemaining(System.ReadOnlySpan`1[int]):int:this (FullOpts)
G_M18869_IG01:
sub rsp, 40
G_M18869_IG02:
mov rax, bword ptr [rdx]
mov ecx, dword ptr [rdx+0x08]
lea edx, [rcx-0x04]
cmp edx, ecx
jae SHORT G_M18869_IG04
mov edx, dword ptr [rax+4*rdx]
lea r8d, [rcx-0x03]
cmp r8d, ecx
jae SHORT G_M18869_IG04
or edx, dword ptr [rax+4*r8]
lea r8d, [rcx-0x02]
cmp r8d, ecx
jae SHORT G_M18869_IG04
or edx, dword ptr [rax+4*r8]
dec ecx
or edx, dword ptr [rax+4*rcx]
mov eax, edx
G_M18869_IG03:
add rsp, 40
ret
G_M18869_IG04:
call CORINFO_HELP_RNGCHKFAIL
int3
; Total bytes of code: 64