VPVectorPointer for part 0 is just the pointer operand. Simplify it
after unrolling. This removes a large number of redundant GEPs with
index 0.
PR: https://github.com/llvm/llvm-project/pull/149735
Materialize constant vector trip counts before ::execute, if the trip
count can be computed as Original (TC / (VF * UF)) * (VF * UF). For now
this excludes when the tail is folded or scalar epilogues are required.
This enables removing a number of redundant branches from the middle
block.
For now this is also only done when not vectorizing the epilogue, as the
simplification complicates stitching the 2 plans together.
PR: https://github.com/llvm/llvm-project/pull/142309
Follow-up to dfca6c0d3bf9d1a056 to extend isUnrolled handle any unrolled
VPlan, which means there's a single UF, but it will be > 1 if unrolling
took place.
After unrolling, there may be additional simplifications that can be
applied. One example is removing SCALAR-STEPS for the first part where
only the first lane is demanded.
This removes redundant adds of 0 from a large number of tests (~200),
many which I am still working on updating.
In preparation for removing redundant WideIV steps added in
https://github.com/llvm/llvm-project/pull/119284.
PR: https://github.com/llvm/llvm-project/pull/123655
Consider the following loop:
```
int rdx = init;
for (int i = 0; i < n; ++i)
rdx = (a[i] > b[i]) ? i : rdx;
```
We can vectorize this loop if `i` is an increasing induction variable.
The final reduced value will be the maximum of `i` that the condition
`a[i] > b[i]` is satisfied, or the start value `init`.
This patch added new RecurKind enums - IFindLastIV and FFindLastIV.
---------
Co-authored-by: Alexey Bataev <5361294+alexey-bataev@users.noreply.github.com>
The most straightforward extension to D150851 would involve handling the
decreasing IV case, for which tests have been added in 110ec1863a
(LoopVectorize/iv-select-cmp: add test for decreasing IV, const start).
However, the commit missed a testcase for the out-of-bound sentinel
value LONG_MAX, which should not be vectorized. Fix this by adding a
test corresponding to the following program:
long test(long *a) {
long rdx = 331;
for (long i = LONG_MAX; i >= 0; i--) {
if (a[i] > 3)
rdx = i;
}
return rdx;
}
Differential Revision: https://reviews.llvm.org/D157969
The current tests in iv-select-cmp.ll are not representative of clang
output of common real-world C programs, which are often written with i32
induction vars, as opposed to i64 induction vars. Hence, add five tests
corresponding to the following programs:
int test(int *a, int n) {
int rdx = 331;
for (int i = 0; i < n; i++) {
if (a[i] > 3)
rdx = i;
}
return rdx;
}
int test(int *a) {
int rdx = 331;
for (int i = 0; i < 20000; i++) {
if (a[i] > 3)
rdx = i;
}
return rdx;
}
int test(int *a, long n) {
int rdx = 331;
for (int i = 0; i < n; i++) {
if (a[i] > 3)
rdx = i;
}
return rdx;
}
int test(int *a, unsigned n) {
int rdx = 331;
for (int i = 0; i < n; i++) {
if (a[i] > 3)
rdx = i;
}
return rdx;
}
int test(int *a) {
int rdx = 331;
for (long i = INT_MIN - 1; i < UINT_MAX; i++) {
if (a[i] > 3)
rdx = i;
}
return rdx;
}
The first two can theoretically be vectorized without a runtime-check,
while the third and fourth cannot. The fifth cannot be vectorized, even
with a runtime-check.
This issue was found while reviewing D150851.
Differential Revision: https://reviews.llvm.org/D156124
The most straightforward extension to D150851 would involve a loop with
decreasing induction variable, with a constant start value.
iv-select-cmp.ll only contains a negative test for the decreasing
induction variable case when the start value is variable, namely
not_vectorized_select_decreasing_induction_icmp. Hence, add a test for
the most straightforward extension to D150851, in preparation to
vectorize:
long rdx = 331;
for (long i = 19999; i >= 0; i--) {
if (a[i] > 3)
rdx = i;
}
return rdx;
Differential Revision: https://reviews.llvm.org/D156152
