[llvm-branch-commits] [llvm] [LoopInterchange] Add test with dependency `[* =]` and `[= *]` (NFC) (PR #193479)

via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Wed Apr 22 06:03:47 PDT 2026


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Ryotaro Kasuga (kasuga-fj)

<details>
<summary>Changes</summary>

Add test cases that are legal to interchange but currently cannot be interchanged due to restrictions in the legality check.

---
Full diff: https://github.com/llvm/llvm-project/pull/193479.diff


1 Files Affected:

- (added) llvm/test/Transforms/LoopInterchange/dependency-all-eq.ll (+117) 


``````````diff
diff --git a/llvm/test/Transforms/LoopInterchange/dependency-all-eq.ll b/llvm/test/Transforms/LoopInterchange/dependency-all-eq.ll
new file mode 100644
index 0000000000000..7c5dd5489ef1b
--- /dev/null
+++ b/llvm/test/Transforms/LoopInterchange/dependency-all-eq.ll
@@ -0,0 +1,117 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt < %s -S -passes=loop-interchange -loop-interchange-profitabilities=instorder \
+; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-PROFIT-INSTORDER
+; RUN: opt < %s -S -passes=loop-interchange -loop-interchange-profitabilities=ignore \
+; RUN:     | FileCheck %s --check-prefixes=CHECK,CHECK-PROFIT-IGNORE
+
+; for (i = 0; i < 100; i++)
+;   for (j = 0; j < 100; j++)
+;     A[j] = 0;
+;
+; The direction vector for this loop nest is [* =]. Interchanging the loops is
+; legal.
+;
+
+define void @all_eq(ptr %A) {
+; CHECK-LABEL: define void @all_eq(
+; CHECK-SAME: ptr [[A:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP_I_HEADER:.*]]
+; CHECK:       [[LOOP_I_HEADER]]:
+; CHECK-NEXT:    [[I:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[I_INC:%.*]], %[[LOOP_I_LATCH:.*]] ]
+; CHECK-NEXT:    br label %[[LOOP_J:.*]]
+; CHECK:       [[LOOP_J]]:
+; CHECK-NEXT:    [[J:%.*]] = phi i64 [ 0, %[[LOOP_I_HEADER]] ], [ [[J_INC:%.*]], %[[LOOP_J]] ]
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i8, ptr [[A]], i64 [[J]]
+; CHECK-NEXT:    store i8 0, ptr [[GEP]], align 1
+; CHECK-NEXT:    [[J_INC]] = add i64 [[J]], 1
+; CHECK-NEXT:    [[EC_J:%.*]] = icmp eq i64 [[J_INC]], 100
+; CHECK-NEXT:    br i1 [[EC_J]], label %[[LOOP_I_LATCH]], label %[[LOOP_J]]
+; CHECK:       [[LOOP_I_LATCH]]:
+; CHECK-NEXT:    [[I_INC]] = add i64 [[I]], 1
+; CHECK-NEXT:    [[EC_I:%.*]] = icmp eq i64 [[I_INC]], 100
+; CHECK-NEXT:    br i1 [[EC_I]], label %[[EXIT:.*]], 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 = getelementptr i8, ptr %A, i64 %j
+  store i8 0, ptr %gep
+  %j.inc = add i64 %j, 1
+  %ec.j = icmp eq i64 %j.inc, 100
+  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, 100
+  br i1 %ec.i, label %exit, label %loop.i.header
+
+exit:
+  ret void
+}
+
+
+; for (i = 0; i < 100; i++)
+;   for (j = 0; j < 100; j++)
+;     A[i] = 0;
+;
+; The direction vector for this loop nest is [= *]. Interchanging the loops is
+; legal.
+;
+
+define void @eq_all(ptr %A) {
+; CHECK-LABEL: define void @eq_all(
+; CHECK-SAME: ptr [[A:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP_I_HEADER:.*]]
+; CHECK:       [[LOOP_I_HEADER]]:
+; CHECK-NEXT:    [[I:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[I_INC:%.*]], %[[LOOP_I_LATCH:.*]] ]
+; CHECK-NEXT:    br label %[[LOOP_J:.*]]
+; CHECK:       [[LOOP_J]]:
+; CHECK-NEXT:    [[J:%.*]] = phi i64 [ 0, %[[LOOP_I_HEADER]] ], [ [[J_INC:%.*]], %[[LOOP_J]] ]
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i8, ptr [[A]], i64 [[I]]
+; CHECK-NEXT:    store i8 0, ptr [[GEP]], align 1
+; CHECK-NEXT:    [[J_INC]] = add i64 [[J]], 1
+; CHECK-NEXT:    [[EC_J:%.*]] = icmp eq i64 [[J_INC]], 100
+; CHECK-NEXT:    br i1 [[EC_J]], label %[[LOOP_I_LATCH]], label %[[LOOP_J]]
+; CHECK:       [[LOOP_I_LATCH]]:
+; CHECK-NEXT:    [[I_INC]] = add i64 [[I]], 1
+; CHECK-NEXT:    [[EC_I:%.*]] = icmp eq i64 [[I_INC]], 100
+; CHECK-NEXT:    br i1 [[EC_I]], label %[[EXIT:.*]], 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 = getelementptr i8, ptr %A, i64 %i
+  store i8 0, ptr %gep
+  %j.inc = add i64 %j, 1
+  %ec.j = icmp eq i64 %j.inc, 100
+  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, 100
+  br i1 %ec.i, label %exit, label %loop.i.header
+
+exit:
+  ret void
+}
+;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+; CHECK-PROFIT-IGNORE: {{.*}}
+; CHECK-PROFIT-INSTORDER: {{.*}}

``````````

</details>


https://github.com/llvm/llvm-project/pull/193479


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