[llvm] a3dfedf - [LV] Check both cases in hints-trans.ll: live and dead scalar loop.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2025-09-01T11:53:40+01:00
New Revision: a3dfedf09e017b00cb3cf5235c24cc57b96eb5b6

URL: https://github.com/llvm/llvm-project/commit/a3dfedf09e017b00cb3cf5235c24cc57b96eb5b6
DIFF: https://github.com/llvm/llvm-project/commit/a3dfedf09e017b00cb3cf5235c24cc57b96eb5b6.diff

LOG: [LV] Check both cases in hints-trans.ll: live and dead scalar loop.

Update hints-trans.ll to check both cases: 1) live scalar loop after
vectorization, 2) dead scalar loop after vectorization.

Added: 
    

Modified: 
    llvm/test/Transforms/LoopVectorize/hints-trans.ll

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/LoopVectorize/hints-trans.ll b/llvm/test/Transforms/LoopVectorize/hints-trans.ll
index 3c7ef44f1d340..853be301da40f 100644
--- a/llvm/test/Transforms/LoopVectorize/hints-trans.ll
+++ b/llvm/test/Transforms/LoopVectorize/hints-trans.ll
@@ -1,29 +1,84 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
 ; RUN: opt -S -passes=loop-vectorize,instsimplify,simplifycfg -force-vector-interleave=1 -force-vector-width=4 -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck %s
+
 ; Note: -passes=instsimplify,simplifycfg -simplifycfg-require-and-preserve-domtree=1 remove the (now dead) original loop, making
 ; it easy to test that the llvm.loop.unroll.disable hint is still present.
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
-; Function Attrs: norecurse nounwind uwtable
-define void @foo(ptr nocapture %b) #0 {
+define void @scalar_loop_dead_after_vectorization(ptr nocapture %b) {
+; CHECK-LABEL: define void @scalar_loop_dead_after_vectorization(
+; CHECK-SAME: ptr captures(none) [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
+; CHECK:       [[VECTOR_BODY]]:
+; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
+; CHECK-NEXT:    store <4 x i32> splat (i32 1), ptr [[TMP0]], align 4
+; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i64 [[INDEX_NEXT]], 16
+; CHECK-NEXT:    br i1 [[TMP1]], label %[[EXIT:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret void
+;
 entry:
-  br label %for.body
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %arrayidx = getelementptr inbounds i32, ptr %b, i64 %iv
+  store i32 1, ptr %arrayidx, align 4
+  %iv.next = add nuw nsw i64 %iv, 1
+  %ec = icmp eq i64 %iv.next, 16
+  br i1 %ec, label %exit, label %loop, !llvm.loop !0
 
-for.cond.cleanup:                                 ; preds = %for.body
+exit:
   ret void
+}
 
-for.body:                                         ; preds = %for.body, %entry
-  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
-  %arrayidx = getelementptr inbounds i32, ptr %b, i64 %indvars.iv
+define void @scalar_loop_not_dead_after_vectorization(ptr nocapture %b) {
+; CHECK-LABEL: define void @scalar_loop_not_dead_after_vectorization(
+; CHECK-SAME: ptr captures(none) [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
+; CHECK:       [[VECTOR_BODY]]:
+; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, %[[ENTRY]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
+; CHECK-NEXT:    store <4 x i32> splat (i32 1), ptr [[TMP0]], align 4
+; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i64 [[INDEX_NEXT]], 16
+; CHECK-NEXT:    br i1 [[TMP1]], label %[[LOOP:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP4:![0-9]+]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 16, %[[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[IV]]
+; CHECK-NEXT:    store i32 1, ptr [[ARRAYIDX]], align 4
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
+; CHECK-NEXT:    [[EC:%.*]] = icmp eq i64 [[IV_NEXT]], 17
+; CHECK-NEXT:    br i1 [[EC]], label %[[EXIT:.*]], label %[[LOOP]], !llvm.loop [[LOOP5:![0-9]+]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %arrayidx = getelementptr inbounds i32, ptr %b, i64 %iv
   store i32 1, ptr %arrayidx, align 4
-  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
-  %exitcond = icmp eq i64 %indvars.iv.next, 16
-  br i1 %exitcond, label %for.cond.cleanup, label %for.body, !llvm.loop !0
-}
+  %iv.next = add nuw nsw i64 %iv, 1
+  %ec = icmp eq i64 %iv.next, 17
+  br i1 %ec, label %exit, label %loop, !llvm.loop !0
 
-; CHECK-LABEL: @foo
-; CHECK: = !{!"llvm.loop.unroll.disable"}
+exit:
+  ret void
+}
 
-attributes #0 = { norecurse nounwind uwtable }
 
 !0 = distinct !{!0, !1}
 !1 = !{!"llvm.loop.unroll.disable"}
+;.
+; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]], [[META2:![0-9]+]], [[META3:![0-9]+]]}
+; CHECK: [[META1]] = !{!"llvm.loop.unroll.disable"}
+; CHECK: [[META2]] = !{!"llvm.loop.isvectorized", i32 1}
+; CHECK: [[META3]] = !{!"llvm.loop.unroll.runtime.disable"}
+; CHECK: [[LOOP4]] = distinct !{[[LOOP4]], [[META1]], [[META2]], [[META3]]}
+; CHECK: [[LOOP5]] = distinct !{[[LOOP5]], [[META1]], [[META2]]}
+;.