Displaying 5 results from an estimated 5 matches for "maskedload_endpoints".
2016 Mar 10
2
masked-load endpoints optimization
...that we're loading the endpoints of the vector guarantees
that a full vector load can't have any different faulting/exception
behavior on x86 and most (?) other targets. We would, however, be reading
memory that the program has not explicitly requested.
IR example:
define <4 x i32> @maskedload_endpoints(<4 x i32>* %addr, <4 x i32> %v) {
; load the first and last elements pointed to by %addr and shuffle those
into %v
%res = call <4 x i32> @llvm.masked.load.v4i32(<4 x i32>* %addr, i32 4, <4
x i1> <i1 1, i1 0, i1 0, i1 1>, <4 x i32> %v)
ret <4 x i32&...
2016 Mar 11
3
masked-load endpoints optimization
...nts of the vector guarantees
> that a full vector load can't have any different faulting/exception
> behavior on x86 and most (?) other targets. We would, however, be reading
> memory that the program has not explicitly requested.
>
> IR example:
>
> define <4 x i32> @maskedload_endpoints(<4 x i32>* %addr, <4 x i32> %v) {
>
> ; load the first and last elements pointed to by %addr and shuffle those
> into %v
>
> %res = call <4 x i32> @llvm.masked.load.v4i32(<4 x i32>* %addr, i32 4,
> <4 x i1> <i1 1, i1 0, i1 0, i1 1>, <4 x...
2016 Mar 15
3
the as-if rule / perf vs. security
...nts of the vector guarantees
> that a full vector load can't have any different faulting/exception
> behavior on x86 and most (?) other targets. We would, however, be reading
> memory that the program has not explicitly requested.
>
> IR example:
>
> define <4 x i32> @maskedload_endpoints(<4 x i32>* %addr, <4 x i32> %v) {
>
> ; load the first and last elements pointed to by %addr and shuffle those
> into %v
>
> %res = call <4 x i32> @llvm.masked.load.v4i32(<4 x i32>* %addr, i32 4,
> <4 x i1> <i1 1, i1 0, i1 0, i1 1>, <4 x...
2016 Mar 16
3
the as-if rule / perf vs. security
...uarantees that a full vector load can't have any different
>> faulting/exception behavior on x86 and most (?) other targets. We would,
>> however, be reading memory that the program has not explicitly requested.
>>
>> IR example:
>>
>> define <4 x i32> @maskedload_endpoints(<4 x i32>* %addr, <4 x i32> %v) {
>>
>> ; load the first and last elements pointed to by %addr and shuffle
>> those into %v
>>
>> %res = call <4 x i32> @llvm.masked.load.v4i32(<4 x i32>* %addr, i32 4,
>> <4 x i1> <i1 1, i1 0,...
2016 Mar 16
3
the as-if rule / perf vs. security
...ctor load can't have any different
>>> faulting/exception behavior on x86 and most (?) other targets. We would,
>>> however, be reading memory that the program has not explicitly requested.
>>>
>>> IR example:
>>>
>>> define <4 x i32> @maskedload_endpoints(<4 x i32>* %addr, <4 x i32> %v) {
>>>
>>> ; load the first and last elements pointed to by %addr and shuffle
>>> those into %v
>>>
>>> %res = call <4 x i32> @llvm.masked.load.v4i32(<4 x i32>* %addr, i32 4,
>>> <4 x...