[polly] [polly] Make reduction detection checks more robust - part 2 (PR #80721)
Karthika Devi C via llvm-commits
llvm-commits at lists.llvm.org
Mon Feb 5 10:15:17 PST 2024
https://github.com/kartcq created https://github.com/llvm/llvm-project/pull/80721
Existing redection detection algorithm does two types of memory checks before marking a load store pair as reduction.
Second check is to verify there is no other memory access in ScopStmt overlapping with the memory of load and store that forms the reduction. Existing check misses cases where there could be probable overlap such as
A[V] += A[P];
In the above case there is chance of overlap between A[V] and A[P] which is missed.
This commit addresses this by removing the parameter from space before checking for compatible space.
Part 1 of this patch : [75297](https://github.com/llvm/llvm-project/pull/75297)
>From e0dd9d49b0090f11d764f9beaacfeec1a73aa7a5 Mon Sep 17 00:00:00 2001
From: kartcq <quic_kartc at quicinc.com>
Date: Wed, 24 Jan 2024 22:46:24 -0800
Subject: [PATCH] [polly] Make reduction detection checks more robust - part 2
Existing redection detection algorithm does two types of memory checks
before marking a load store pair as reduction.
Second check is to verify there is no other memory access in ScopStmt
overlapping with the memory of load and store that forms the reduction.
Existing check misses cases where there could be probable overlap such as
A[V] += A[P];
In the above case there is chance of overlap between A[V] and A[P] which
is missed.
This commit addresses this by removing the parameter from space
before checking for compatible space.
---
polly/lib/Analysis/ScopBuilder.cpp | 12 ++++++++----
.../non-affine-loop-condition-dependent-access_2.ll | 4 ++--
.../non-affine-loop-condition-dependent-access_3.ll | 4 ++--
polly/test/ScopInfo/int2ptr_ptr2int.ll | 4 ++--
4 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/polly/lib/Analysis/ScopBuilder.cpp b/polly/lib/Analysis/ScopBuilder.cpp
index 4486164ce0e2a2..0edc41d106415c 100644
--- a/polly/lib/Analysis/ScopBuilder.cpp
+++ b/polly/lib/Analysis/ScopBuilder.cpp
@@ -2516,15 +2516,19 @@ bool hasIntersectingAccesses(isl::set AllAccs, MemoryAccess *LoadMA,
MemoryAccess *StoreMA, isl::set Domain,
SmallVector<MemoryAccess *, 8> &MemAccs) {
bool HasIntersectingAccs = false;
+ auto AllAccsNoParams = AllAccs.project_out_all_params();
+
for (MemoryAccess *MA : MemAccs) {
if (MA == LoadMA || MA == StoreMA)
continue;
+ auto AccRel = MA->getAccessRelation().intersect_domain(Domain);
+ auto Accs = AccRel.range();
+ auto AccsNoParams = Accs.project_out_all_params();
- isl::map AccRel = MA->getAccessRelation().intersect_domain(Domain);
- isl::set Accs = AccRel.range();
+ bool CompatibleSpace = AllAccsNoParams.has_equal_space(AccsNoParams);
- if (AllAccs.has_equal_space(Accs)) {
- isl::set OverlapAccs = Accs.intersect(AllAccs);
+ if (CompatibleSpace) {
+ auto OverlapAccs = Accs.intersect(AllAccs);
bool DoesIntersect = !OverlapAccs.is_empty();
HasIntersectingAccs |= DoesIntersect;
}
diff --git a/polly/test/ScopInfo/NonAffine/non-affine-loop-condition-dependent-access_2.ll b/polly/test/ScopInfo/NonAffine/non-affine-loop-condition-dependent-access_2.ll
index f2574b77d6e5ee..e39569abc52da5 100644
--- a/polly/test/ScopInfo/NonAffine/non-affine-loop-condition-dependent-access_2.ll
+++ b/polly/test/ScopInfo/NonAffine/non-affine-loop-condition-dependent-access_2.ll
@@ -44,9 +44,9 @@
; INNERMOST-NEXT: [p_0, p_1, p_2] -> { Stmt_bb16[i0] -> MemRef_A[p_1] };
; INNERMOST-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
; INNERMOST-NEXT: [p_0, p_1, p_2] -> { Stmt_bb16[i0] -> MemRef_A[p_2] };
-; INNERMOST-NEXT: ReadAccess := [Reduction Type: +] [Scalar: 0]
+; INNERMOST-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
; INNERMOST-NEXT: [p_0, p_1, p_2] -> { Stmt_bb16[i0] -> MemRef_A[p_0 + i0] };
-; INNERMOST-NEXT: MustWriteAccess := [Reduction Type: +] [Scalar: 0]
+; INNERMOST-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 0]
; INNERMOST-NEXT: [p_0, p_1, p_2] -> { Stmt_bb16[i0] -> MemRef_A[p_0 + i0] };
; INNERMOST-NEXT: Stmt_bb26
; INNERMOST-NEXT: Domain :=
diff --git a/polly/test/ScopInfo/NonAffine/non-affine-loop-condition-dependent-access_3.ll b/polly/test/ScopInfo/NonAffine/non-affine-loop-condition-dependent-access_3.ll
index 463db235960800..75dd7ac26bb3ef 100644
--- a/polly/test/ScopInfo/NonAffine/non-affine-loop-condition-dependent-access_3.ll
+++ b/polly/test/ScopInfo/NonAffine/non-affine-loop-condition-dependent-access_3.ll
@@ -44,9 +44,9 @@
; INNERMOST-NEXT: [p_0, p_1, p_2] -> { Stmt_bb16[i0] -> MemRef_A[p_1] };
; INNERMOST-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
; INNERMOST-NEXT: [p_0, p_1, p_2] -> { Stmt_bb16[i0] -> MemRef_A[p_2] };
-; INNERMOST-NEXT: ReadAccess := [Reduction Type: +] [Scalar: 0]
+; INNERMOST-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
; INNERMOST-NEXT: [p_0, p_1, p_2] -> { Stmt_bb16[i0] -> MemRef_A[i0] };
-; INNERMOST-NEXT: MustWriteAccess := [Reduction Type: +] [Scalar: 0]
+; INNERMOST-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 0]
; INNERMOST-NEXT: [p_0, p_1, p_2] -> { Stmt_bb16[i0] -> MemRef_A[i0] };
; INNERMOST-NEXT: Stmt_bb26
; INNERMOST-NEXT: Domain :=
diff --git a/polly/test/ScopInfo/int2ptr_ptr2int.ll b/polly/test/ScopInfo/int2ptr_ptr2int.ll
index 2e7bfbe5eaee3f..9fadc5a8eb2896 100644
--- a/polly/test/ScopInfo/int2ptr_ptr2int.ll
+++ b/polly/test/ScopInfo/int2ptr_ptr2int.ll
@@ -11,9 +11,9 @@
;
; CHECK: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
; CHECK-NEXT: [val, ptr] -> { Stmt_for_body[i0] -> MemRef_A[9 + val] };
-; CHECK-NEXT: ReadAccess := [Reduction Type: +] [Scalar: 0]
+; CHECK-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
; CHECK-NEXT: [val, ptr] -> { Stmt_for_body[i0] -> MemRef_A[9 + ptr] };
-; CHECK-NEXT: MustWriteAccess := [Reduction Type: +] [Scalar: 0]
+; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 0]
; CHECK-NEXT: [val, ptr] -> { Stmt_for_body[i0] -> MemRef_A[9 + ptr] };
;
; IR: entry:
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