https://github.com/kasuga-fj created https://github.com/llvm/llvm-project/pull/203240
None >From d75ef1dfa10c9fcc725e0309ff061bffe87678a1 Mon Sep 17 00:00:00 2001 From: Ryotaro Kasuga <[email protected]> Date: Thu, 11 Jun 2026 09:09:40 +0000 Subject: [PATCH] [LoopInterchange] Add test for extra reduction use in inner loop (NFC) --- .../reduction-extra-use-in-inner-loop.ll | 93 +++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 llvm/test/Transforms/LoopInterchange/reduction-extra-use-in-inner-loop.ll diff --git a/llvm/test/Transforms/LoopInterchange/reduction-extra-use-in-inner-loop.ll b/llvm/test/Transforms/LoopInterchange/reduction-extra-use-in-inner-loop.ll new file mode 100644 index 0000000000000..83d93168a9877 --- /dev/null +++ b/llvm/test/Transforms/LoopInterchange/reduction-extra-use-in-inner-loop.ll @@ -0,0 +1,93 @@ +; 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 + +; sum = 0; +; for (i = 0; i < 4; i++) +; for (j = 0, sum_i = sum; j < 4; j++) { +; sum += A[j][i]; +; B[j][i] = sum_i; +; } +; +; Interchanging the loops will become as follows: +; +; sum = 0; +; for (j = 0; j < 4; j++) +; for (i = 0, sum_j = sum; i < 4; i++) { +; sum_j += A[j][i]; +; B[j][i] = sum_j; +; } +; +; This is invalid transformation because the contens of the array `B` will be +; different. +; +; FIXME: The loops are now interchanged. +; +define i8 @extra_reduction_use_in_inner(ptr noalias %A, ptr noalias %B) { +; CHECK-LABEL: define i8 @extra_reduction_use_in_inner( +; 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: [[SUM_INNER:%.*]] = phi i8 [ [[SUM_NEXT:%.*]], %[[OUTER_LATCH]] ], [ [[SUM:%.*]], %[[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: [[SUM]] = phi i8 [ [[SUM_LCSSA:%.*]], %[[INNER_SPLIT]] ], [ 0, %[[INNER_PREHEADER]] ] +; CHECK-NEXT: br label %[[OUTER_HEADER_PREHEADER]] +; CHECK: [[INNER_SPLIT1]]: +; CHECK-NEXT: [[GEP_A:%.*]] = getelementptr [4 x i8], ptr [[A]], i64 [[J]], i64 [[I]] +; CHECK-NEXT: [[A:%.*]] = load i8, ptr [[GEP_A]], align 1 +; CHECK-NEXT: [[SUM_NEXT]] = add i8 [[SUM_INNER]], [[A]] +; CHECK-NEXT: [[GEP_B:%.*]] = getelementptr [4 x i8], ptr [[B]], i64 [[J]], i64 [[I]] +; CHECK-NEXT: store i8 [[SUM]], ptr [[GEP_B]], align 1 +; CHECK-NEXT: [[J_NEXT:%.*]] = add i64 [[J]], 1 +; CHECK-NEXT: [[EC_J:%.*]] = icmp eq i64 [[J_NEXT]], 4 +; CHECK-NEXT: br label %[[OUTER_LATCH]] +; CHECK: [[INNER_SPLIT]]: +; CHECK-NEXT: [[SUM_LCSSA]] = phi i8 [ [[SUM_NEXT]], %[[OUTER_LATCH]] ] +; CHECK-NEXT: [[TMP0]] = add i64 [[J]], 1 +; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i64 [[TMP0]], 4 +; CHECK-NEXT: br i1 [[TMP1]], label %[[EXIT:.*]], label %[[INNER]] +; CHECK: [[OUTER_LATCH]]: +; CHECK-NEXT: [[I_NEXT]] = add i64 [[I]], 1 +; CHECK-NEXT: [[EC_I:%.*]] = icmp eq i64 [[I_NEXT]], 4 +; CHECK-NEXT: br i1 [[EC_I]], label %[[INNER_SPLIT]], label %[[OUTER_HEADER]] +; CHECK: [[EXIT]]: +; CHECK-NEXT: [[RES:%.*]] = phi i8 [ [[SUM_LCSSA]], %[[INNER_SPLIT]] ] +; CHECK-NEXT: ret i8 [[RES]] +; +entry: + br label %outer.header + +outer.header: + %i = phi i64 [ 0, %entry ], [ %i.next, %outer.latch ] + %sum = phi i8 [ 0, %entry ], [ %sum.lcssa, %outer.latch ] + br label %inner + +inner: + %j = phi i64 [ 0, %outer.header ], [ %j.next, %inner ] + %sum.inner = phi i8 [ %sum, %outer.header ], [ %sum.next, %inner ] + %gep.A = getelementptr [4 x i8], ptr %A, i64 %j, i64 %i + %a = load i8, ptr %gep.A + %sum.next = add i8 %sum.inner, %a + %gep.B = getelementptr [4 x i8], ptr %B, i64 %j, i64 %i + store i8 %sum, ptr %gep.B + %j.next = add i64 %j, 1 + %ec.j = icmp eq i64 %j.next, 4 + br i1 %ec.j, label %outer.latch, label %inner + +outer.latch: + %sum.lcssa = phi i8 [ %sum.next, %inner ] + %i.next = add i64 %i, 1 + %ec.i = icmp eq i64 %i.next, 4 + br i1 %ec.i, label %exit, label %outer.header + +exit: + %res = phi i8 [ %sum.lcssa, %outer.latch ] + ret i8 %res +} _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
