[llvm] [LoopInterchange] Add test where loop has memory-affected calls (NFC) (PR #200827)
Ryotaro Kasuga via llvm-commits
llvm-commits at lists.llvm.org
Mon Jun 1 07:45:21 PDT 2026
https://github.com/kasuga-fj updated https://github.com/llvm/llvm-project/pull/200827
>From 460bdfd08f6e1ec9e95b2e426771125ca5500fde Mon Sep 17 00:00:00 2001
From: Ryotaro Kasuga <kasuga.ryotaro at fujitsu.com>
Date: Mon, 1 Jun 2026 13:33:57 +0000
Subject: [PATCH] [LoopInterchange] Add test where loop has memory-affected
calls (NFC)
---
.../Transforms/LoopInterchange/memory-attr.ll | 140 ++++++++++++++++++
1 file changed, 140 insertions(+)
create mode 100644 llvm/test/Transforms/LoopInterchange/memory-attr.ll
diff --git a/llvm/test/Transforms/LoopInterchange/memory-attr.ll b/llvm/test/Transforms/LoopInterchange/memory-attr.ll
new file mode 100644
index 0000000000000..c32f48ef63694
--- /dev/null
+++ b/llvm/test/Transforms/LoopInterchange/memory-attr.ll
@@ -0,0 +1,140 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt < %s -passes=loop-interchange -loop-interchange-profitabilities=ignore -S | FileCheck %s
+
+; for (i = 0; i < 100; i++)
+; for (j = 0; j < 100; j++)
+; writeonly(A);
+;
+; The writeonly call may write to `%A` at some unknown index, so we cannot
+; interchange the loops.
+;
+; FIXME: These loops are now interchanged.
+;
+define void @call_writeonly(ptr %A) {
+; CHECK-LABEL: define void @call_writeonly(
+; CHECK-SAME: ptr [[A:%.*]]) {
+; CHECK-NEXT: [[INNER_PREHEADER:.*:]]
+; CHECK-NEXT: br label %[[INNER:.*]]
+; CHECK: [[OUTER_HEADER_PREHEADER1:.*]]:
+; CHECK-NEXT: br label %[[OUTER_HEADER_PREHEADER:.*]]
+; CHECK: [[OUTER_HEADER_PREHEADER]]:
+; CHECK-NEXT: [[I:%.*]] = phi i64 [ [[I_NEXT:%.*]], %[[OUTER_LATCH:.*]] ], [ 0, %[[OUTER_HEADER_PREHEADER1]] ]
+; CHECK-NEXT: br label %[[INNER_SPLIT1:.*]]
+; CHECK: [[INNER]]:
+; CHECK-NEXT: br label %[[INNER1:.*]]
+; CHECK: [[INNER1]]:
+; CHECK-NEXT: [[J:%.*]] = phi i64 [ [[TMP2:%.*]], %[[INNER_SPLIT:.*]] ], [ 0, %[[INNER]] ]
+; CHECK-NEXT: br label %[[OUTER_HEADER_PREHEADER1]]
+; CHECK: [[INNER_SPLIT1]]:
+; CHECK-NEXT: call void @writeonly(ptr [[A]])
+; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[J]], 1
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 100
+; CHECK-NEXT: br label %[[OUTER_LATCH]]
+; CHECK: [[INNER_SPLIT]]:
+; CHECK-NEXT: [[TMP2]] = add i64 [[J]], 1
+; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i64 [[TMP2]], 100
+; CHECK-NEXT: br i1 [[TMP3]], label %[[EXIT:.*]], label %[[INNER1]]
+; CHECK: [[OUTER_LATCH]]:
+; CHECK-NEXT: [[I_NEXT]] = add i64 [[I]], 1
+; CHECK-NEXT: [[EC_OUTER:%.*]] = icmp eq i64 [[I_NEXT]], 100
+; CHECK-NEXT: br i1 [[EC_OUTER]], label %[[INNER_SPLIT]], label %[[OUTER_HEADER_PREHEADER]]
+; CHECK: [[EXIT]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %outer.header
+
+outer.header:
+ %i = phi i64 [ 0, %entry ], [ %i.next, %outer.latch ]
+ br label %inner
+
+inner:
+ %j = phi i64 [ 0, %outer.header ], [ %j.next, %inner ]
+ call void @writeonly(ptr %A)
+ %j.next = add i64 %j, 1
+ %ec.inner = icmp eq i64 %j.next, 100
+ br i1 %ec.inner, label %outer.latch, label %inner
+
+outer.latch:
+ %i.next = add i64 %i, 1
+ %ec.outer = icmp eq i64 %i.next, 100
+ br i1 %ec.outer, label %exit, label %outer.header
+
+exit:
+ ret void
+}
+
+; for (i = 0; i < 100; i++)
+; for (j = 0; j < 100; j++) {
+; A[j][i] = 0;
+; val = mem_none(A);
+; B[j][i] = val;
+; }
+;
+; The mem_none call doesn't read or write the memory, so we can interchange the
+; loops.
+;
+define void @call_mem_none(ptr noalias %A, ptr noalias %B) {
+; CHECK-LABEL: define void @call_mem_none(
+; CHECK-SAME: ptr noalias [[A:%.*]], ptr noalias [[B:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: br label %[[INNER_PREHEADER:.*]]
+; CHECK: [[OUTER_HEADER_PREHEADER:.*]]:
+; CHECK-NEXT: br label %[[OUTER_HEADER:.*]]
+; CHECK: [[OUTER_HEADER]]:
+; CHECK-NEXT: [[I:%.*]] = phi i64 [ [[I_NEXT:%.*]], %[[OUTER_LATCH:.*]] ], [ 0, %[[OUTER_HEADER_PREHEADER]] ]
+; CHECK-NEXT: br label %[[INNER_SPLIT1:.*]]
+; CHECK: [[INNER_PREHEADER]]:
+; CHECK-NEXT: br label %[[INNER:.*]]
+; CHECK: [[INNER]]:
+; CHECK-NEXT: [[J:%.*]] = phi i64 [ [[TMP0:%.*]], %[[INNER_SPLIT:.*]] ], [ 0, %[[INNER_PREHEADER]] ]
+; CHECK-NEXT: br label %[[OUTER_HEADER_PREHEADER]]
+; CHECK: [[INNER_SPLIT1]]:
+; CHECK-NEXT: [[GEP_A:%.*]] = getelementptr [100 x i32], ptr [[A]], i64 [[J]], i64 [[I]]
+; CHECK-NEXT: store i32 0, ptr [[GEP_A]], align 4
+; CHECK-NEXT: [[VAL:%.*]] = call i32 @mem_none(ptr [[A]])
+; CHECK-NEXT: [[GEP_B:%.*]] = getelementptr [100 x i32], ptr [[B]], i64 [[J]], i64 [[I]]
+; CHECK-NEXT: store i32 [[VAL]], ptr [[GEP_B]], align 4
+; CHECK-NEXT: [[J_NEXT:%.*]] = add i64 [[J]], 1
+; CHECK-NEXT: [[EC_INNER:%.*]] = icmp eq i64 [[J_NEXT]], 100
+; CHECK-NEXT: br label %[[OUTER_LATCH]]
+; CHECK: [[INNER_SPLIT]]:
+; CHECK-NEXT: [[TMP0]] = add i64 [[J]], 1
+; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 100
+; CHECK-NEXT: br i1 [[TMP1]], label %[[EXIT:.*]], label %[[INNER]]
+; CHECK: [[OUTER_LATCH]]:
+; CHECK-NEXT: [[I_NEXT]] = add i64 [[I]], 1
+; CHECK-NEXT: [[EC_OUTER:%.*]] = icmp eq i64 [[I_NEXT]], 100
+; CHECK-NEXT: br i1 [[EC_OUTER]], label %[[INNER_SPLIT]], label %[[OUTER_HEADER]]
+; CHECK: [[EXIT]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %outer.header
+
+outer.header:
+ %i = phi i64 [ 0, %entry ], [ %i.next, %outer.latch ]
+ br label %inner
+
+inner:
+ %j = phi i64 [ 0, %outer.header ], [ %j.next, %inner ]
+ %gep.A = getelementptr [100 x i32], ptr %A, i64 %j, i64 %i
+ store i32 0, ptr %gep.A
+ %val = call i32 @mem_none(ptr %A)
+ %gep.B = getelementptr [100 x i32], ptr %B, i64 %j, i64 %i
+ store i32 %val, ptr %gep.B
+ %j.next = add i64 %j, 1
+ %ec.inner = icmp eq i64 %j.next, 100
+ br i1 %ec.inner, label %outer.latch, label %inner
+
+outer.latch:
+ %i.next = add i64 %i, 1
+ %ec.outer = icmp eq i64 %i.next, 100
+ br i1 %ec.outer, label %exit, label %outer.header
+
+exit:
+ ret void
+}
+
+declare void @writeonly(ptr %p) memory(write)
+declare void @mem_none(ptr %p) memory(none)
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