[llvm-branch-commits] [llvm] [LoopInterchange] Add test for multiple accesses to same base ptr (NFC) (PR #193476)
Ryotaro Kasuga via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Mon May 18 06:29:27 PDT 2026
https://github.com/kasuga-fj updated https://github.com/llvm/llvm-project/pull/193476
>From 675374e0d054fae3b14e34d7c1a5a5f1cefe3abe Mon Sep 17 00:00:00 2001
From: Ryotaro Kasuga <kasuga.ryotaro at fujitsu.com>
Date: Wed, 22 Apr 2026 10:26:38 +0000
Subject: [PATCH 1/2] [LoopInterchange] Add test for multiple accesses to same
base ptr (NFC)
---
.../profitability-instorder.ll | 88 ++++++++++++++++++-
1 file changed, 86 insertions(+), 2 deletions(-)
diff --git a/llvm/test/Transforms/LoopInterchange/profitability-instorder.ll b/llvm/test/Transforms/LoopInterchange/profitability-instorder.ll
index 421f467e42a5b..d0f9447193acd 100644
--- a/llvm/test/Transforms/LoopInterchange/profitability-instorder.ll
+++ b/llvm/test/Transforms/LoopInterchange/profitability-instorder.ll
@@ -141,8 +141,8 @@ exit:
;
; The above loop should NOT be interchanged in terms of locality of reference.
;
-define void @unprofitable(ptr %A) {
-; CHECK-LABEL: define void @unprofitable(
+define void @unprofitable0(ptr %A) {
+; CHECK-LABEL: define void @unprofitable0(
; CHECK-SAME: ptr [[A:%.*]]) {
; CHECK-NEXT: [[LOOP_I_HEADER_PREHEADER:.*]]:
; CHECK-NEXT: br label %[[LOOP_I_HEADER1:.*]]
@@ -188,3 +188,87 @@ loop.i.latch:
exit:
ret void
}
+
+; for (i = 0; i < 10; i++)
+; for (j = 0; j < 10; j++)
+; A[100*i + j] = B[100*i + j] + C[i + 100*j] + C[i + 99*j] + C[i + 98*j];
+;
+; The above loop should NOT be interchanged in terms of locality of reference.
+;
+define void @unprofitable1(ptr noalias %A, ptr noalias %B, ptr noalias %C) {
+; CHECK-LABEL: define void @unprofitable1(
+; CHECK-SAME: ptr noalias [[A:%.*]], ptr noalias [[B:%.*]], ptr noalias [[C:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: br label %[[LOOP_J_PREHEADER:.*]]
+; CHECK: [[LOOP_I_HEADER_PREHEADER:.*]]:
+; CHECK-NEXT: br label %[[LOOP_I_HEADER:.*]]
+; CHECK: [[LOOP_I_HEADER]]:
+; CHECK-NEXT: [[I:%.*]] = phi i64 [ [[I_INC:%.*]], %[[LOOP_I_LATCH:.*]] ], [ 0, %[[LOOP_I_HEADER_PREHEADER]] ]
+; CHECK-NEXT: br label %[[LOOP_J_SPLIT1:.*]]
+; CHECK: [[LOOP_J_PREHEADER]]:
+; CHECK-NEXT: br label %[[LOOP_J:.*]]
+; CHECK: [[LOOP_J]]:
+; CHECK-NEXT: [[J:%.*]] = phi i64 [ [[TMP0:%.*]], %[[LOOP_J_SPLIT:.*]] ], [ 0, %[[LOOP_J_PREHEADER]] ]
+; CHECK-NEXT: br label %[[LOOP_I_HEADER_PREHEADER]]
+; CHECK: [[LOOP_J_SPLIT1]]:
+; CHECK-NEXT: [[GEP_A:%.*]] = getelementptr inbounds [100 x i8], ptr [[A]], i64 [[I]], i64 [[J]]
+; CHECK-NEXT: [[GEP_B:%.*]] = getelementptr inbounds [100 x i8], ptr [[B]], i64 [[I]], i64 [[J]]
+; CHECK-NEXT: [[GEP_C0:%.*]] = getelementptr inbounds [100 x i8], ptr [[C]], i64 [[J]], i64 [[I]]
+; CHECK-NEXT: [[GEP_C1:%.*]] = getelementptr inbounds [99 x i8], ptr [[C]], i64 [[J]], i64 [[I]]
+; CHECK-NEXT: [[GEP_C2:%.*]] = getelementptr inbounds [98 x i8], ptr [[C]], i64 [[J]], i64 [[I]]
+; CHECK-NEXT: [[VAL_B:%.*]] = load i8, ptr [[GEP_B]], align 1
+; CHECK-NEXT: [[VAL_C0:%.*]] = load i8, ptr [[GEP_C0]], align 1
+; CHECK-NEXT: [[VAL_C1:%.*]] = load i8, ptr [[GEP_C1]], align 1
+; CHECK-NEXT: [[VAL_C2:%.*]] = load i8, ptr [[GEP_C2]], align 1
+; CHECK-NEXT: [[SUM_0:%.*]] = add i8 [[VAL_B]], [[VAL_C0]]
+; CHECK-NEXT: [[SUM_1:%.*]] = add i8 [[SUM_0]], [[VAL_C1]]
+; CHECK-NEXT: [[SUM_2:%.*]] = add i8 [[SUM_1]], [[VAL_C2]]
+; CHECK-NEXT: store i8 [[SUM_2]], ptr [[GEP_A]], align 1
+; CHECK-NEXT: [[J_INC:%.*]] = add i64 [[J]], 1
+; CHECK-NEXT: [[EC_J:%.*]] = icmp eq i64 [[J_INC]], 10
+; CHECK-NEXT: br label %[[LOOP_I_LATCH]]
+; CHECK: [[LOOP_J_SPLIT]]:
+; CHECK-NEXT: [[TMP0]] = add i64 [[J]], 1
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 10
+; CHECK-NEXT: br i1 [[TMP1]], label %[[EXIT:.*]], label %[[LOOP_J]]
+; CHECK: [[LOOP_I_LATCH]]:
+; CHECK-NEXT: [[I_INC]] = add i64 [[I]], 1
+; CHECK-NEXT: [[EC_I:%.*]] = icmp eq i64 [[I_INC]], 10
+; CHECK-NEXT: br i1 [[EC_I]], label %[[LOOP_J_SPLIT]], label %[[LOOP_I_HEADER]]
+; CHECK: [[EXIT]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %loop.i.header
+
+loop.i.header:
+ %i = phi i64 [ 0, %entry ], [ %i.inc, %loop.i.latch ]
+ br label %loop.j
+
+loop.j:
+ %j = phi i64 [ 0, %loop.i.header ], [ %j.inc, %loop.j ]
+ %gep.A = getelementptr inbounds [100 x i8], ptr %A, i64 %i, i64 %j
+ %gep.B = getelementptr inbounds [100 x i8], ptr %B, i64 %i, i64 %j
+ %gep.C0 = getelementptr inbounds [100 x i8], ptr %C, i64 %j, i64 %i
+ %gep.C1 = getelementptr inbounds [99 x i8], ptr %C, i64 %j, i64 %i
+ %gep.C2 = getelementptr inbounds [98 x i8], ptr %C, i64 %j, i64 %i
+ %val.B = load i8, ptr %gep.B
+ %val.C0 = load i8, ptr %gep.C0
+ %val.C1 = load i8, ptr %gep.C1
+ %val.C2 = load i8, ptr %gep.C2
+ %sum.0 = add i8 %val.B, %val.C0
+ %sum.1 = add i8 %sum.0, %val.C1
+ %sum.2 = add i8 %sum.1, %val.C2
+ store i8 %sum.2, ptr %gep.A
+ %j.inc = add i64 %j, 1
+ %ec.j = icmp eq i64 %j.inc, 10
+ br i1 %ec.j, label %loop.i.latch, label %loop.j
+
+loop.i.latch:
+ %i.inc = add i64 %i, 1
+ %ec.i = icmp eq i64 %i.inc, 10
+ br i1 %ec.i, label %exit, label %loop.i.header
+
+exit:
+ ret void
+}
>From 1e02219be8001355902a7e8fecbff7321926942d Mon Sep 17 00:00:00 2001
From: Ryotaro Kasuga <kasuga.ryotaro at fujitsu.com>
Date: Mon, 18 May 2026 13:28:46 +0000
Subject: [PATCH 2/2] address review comment
---
.../LoopInterchange/profitability-instorder.ll | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/llvm/test/Transforms/LoopInterchange/profitability-instorder.ll b/llvm/test/Transforms/LoopInterchange/profitability-instorder.ll
index d0f9447193acd..9479eaa00a1f0 100644
--- a/llvm/test/Transforms/LoopInterchange/profitability-instorder.ll
+++ b/llvm/test/Transforms/LoopInterchange/profitability-instorder.ll
@@ -189,8 +189,8 @@ exit:
ret void
}
-; for (i = 0; i < 10; i++)
-; for (j = 0; j < 10; j++)
+; for (i = 0; i < 42; i++)
+; for (j = 0; j < 42; j++)
; A[100*i + j] = B[100*i + j] + C[i + 100*j] + C[i + 99*j] + C[i + 98*j];
;
; The above loop should NOT be interchanged in terms of locality of reference.
@@ -225,15 +225,15 @@ define void @unprofitable1(ptr noalias %A, ptr noalias %B, ptr noalias %C) {
; CHECK-NEXT: [[SUM_2:%.*]] = add i8 [[SUM_1]], [[VAL_C2]]
; CHECK-NEXT: store i8 [[SUM_2]], ptr [[GEP_A]], align 1
; CHECK-NEXT: [[J_INC:%.*]] = add i64 [[J]], 1
-; CHECK-NEXT: [[EC_J:%.*]] = icmp eq i64 [[J_INC]], 10
+; CHECK-NEXT: [[EC_J:%.*]] = icmp eq i64 [[J_INC]], 42
; CHECK-NEXT: br label %[[LOOP_I_LATCH]]
; CHECK: [[LOOP_J_SPLIT]]:
; CHECK-NEXT: [[TMP0]] = add i64 [[J]], 1
-; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 10
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 42
; CHECK-NEXT: br i1 [[TMP1]], label %[[EXIT:.*]], label %[[LOOP_J]]
; CHECK: [[LOOP_I_LATCH]]:
; CHECK-NEXT: [[I_INC]] = add i64 [[I]], 1
-; CHECK-NEXT: [[EC_I:%.*]] = icmp eq i64 [[I_INC]], 10
+; CHECK-NEXT: [[EC_I:%.*]] = icmp eq i64 [[I_INC]], 42
; CHECK-NEXT: br i1 [[EC_I]], label %[[LOOP_J_SPLIT]], label %[[LOOP_I_HEADER]]
; CHECK: [[EXIT]]:
; CHECK-NEXT: ret void
@@ -261,12 +261,12 @@ loop.j:
%sum.2 = add i8 %sum.1, %val.C2
store i8 %sum.2, ptr %gep.A
%j.inc = add i64 %j, 1
- %ec.j = icmp eq i64 %j.inc, 10
+ %ec.j = icmp eq i64 %j.inc, 42
br i1 %ec.j, label %loop.i.latch, label %loop.j
loop.i.latch:
%i.inc = add i64 %i, 1
- %ec.i = icmp eq i64 %i.inc, 10
+ %ec.i = icmp eq i64 %i.inc, 42
br i1 %ec.i, label %exit, label %loop.i.header
exit:
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