[llvm] [FIXME] Add test case for tail fold my masking with external users (PR #82329)

Niwin Anto via llvm-commits llvm-commits at lists.llvm.org
Tue Feb 20 01:36:29 PST 2024


https://github.com/niwinanto created https://github.com/llvm/llvm-project/pull/82329

Test case for https://github.com/llvm/llvm-project/issues/76069

>From ee95e2c242e28355d2cb8dbfe8506d82147c0d0f Mon Sep 17 00:00:00 2001
From: Niwin Anto <niwin.anto at hightec-rt.com>
Date: Tue, 13 Feb 2024 20:25:52 +0100
Subject: [PATCH] [FIXME] Add test case for tail fold my masking with external
 users

---
 ...o-fold-tail-by-masking-iv-external-uses.ll | 122 ++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 llvm/test/Transforms/LoopVectorize/no-fold-tail-by-masking-iv-external-uses.ll

diff --git a/llvm/test/Transforms/LoopVectorize/no-fold-tail-by-masking-iv-external-uses.ll b/llvm/test/Transforms/LoopVectorize/no-fold-tail-by-masking-iv-external-uses.ll
new file mode 100644
index 00000000000000..0e9f00e8224785
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/no-fold-tail-by-masking-iv-external-uses.ll
@@ -0,0 +1,122 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt < %s -passes=loop-vectorize -force-vector-width=4 -force-vector-interleave=1 -S | FileCheck %s
+
+; The vectorizer should refuse to fold the tail by masking because
+; %conv is used outside of the loop. Test for this by checking that
+; %n.vec, the vector trip count, is rounded down to the next multiple of
+; 4. If folding the tail, it would have been rounded up instead.
+; Test case for #76069.
+define i32 @test(ptr %arr, i64 %n) {
+; CHECK-LABEL: define i32 @test(
+; CHECK-SAME: ptr [[ARR:%.*]], i64 [[N:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i64 [[N]], 1
+; CHECK-NEXT:    br i1 [[CMP1]], label [[PREHEADER:%.*]], label [[DONE:%.*]]
+; CHECK:       preheader:
+; CHECK-NEXT:    [[TMP0:%.*]] = add i64 [[N]], -1
+; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP0]], 4
+; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
+; CHECK:       vector.scevcheck:
+; CHECK-NEXT:    [[TMP1:%.*]] = add i64 [[N]], -2
+; CHECK-NEXT:    [[TMP2:%.*]] = trunc i64 [[TMP1]] to i8
+; CHECK-NEXT:    [[TMP3:%.*]] = add i8 1, [[TMP2]]
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp ult i8 [[TMP3]], 1
+; CHECK-NEXT:    [[TMP5:%.*]] = icmp ugt i64 [[TMP1]], 255
+; CHECK-NEXT:    [[TMP6:%.*]] = or i1 [[TMP4]], [[TMP5]]
+; CHECK-NEXT:    [[TMP7:%.*]] = trunc i64 [[TMP1]] to i8
+; CHECK-NEXT:    [[TMP8:%.*]] = add i8 2, [[TMP7]]
+; CHECK-NEXT:    [[TMP9:%.*]] = icmp ult i8 [[TMP8]], 2
+; CHECK-NEXT:    [[TMP10:%.*]] = icmp ugt i64 [[TMP1]], 255
+; CHECK-NEXT:    [[TMP11:%.*]] = or i1 [[TMP9]], [[TMP10]]
+; CHECK-NEXT:    [[TMP12:%.*]] = or i1 [[TMP6]], [[TMP11]]
+; CHECK-NEXT:    br i1 [[TMP12]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
+; CHECK:       vector.ph:
+; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[TMP0]], 4
+; CHECK-NEXT:    [[N_VEC:%.*]] = sub i64 [[TMP0]], [[N_MOD_VF]]
+; CHECK-NEXT:    [[IND_END:%.*]] = add i64 1, [[N_VEC]]
+; CHECK-NEXT:    [[DOTCAST:%.*]] = trunc i64 [[N_VEC]] to i8
+; CHECK-NEXT:    [[IND_END1:%.*]] = add i8 1, [[DOTCAST]]
+; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
+; CHECK:       vector.body:
+; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
+; CHECK-NEXT:    [[OFFSET_IDX:%.*]] = add i64 1, [[INDEX]]
+; CHECK-NEXT:    [[TMP13:%.*]] = add i64 [[OFFSET_IDX]], 0
+; CHECK-NEXT:    [[TMP14:%.*]] = add i64 [[OFFSET_IDX]], 1
+; CHECK-NEXT:    [[TMP15:%.*]] = add i64 [[OFFSET_IDX]], 2
+; CHECK-NEXT:    [[TMP16:%.*]] = add i64 [[OFFSET_IDX]], 3
+; CHECK-NEXT:    [[TMP17:%.*]] = add nsw i64 [[TMP13]], -1
+; CHECK-NEXT:    [[TMP18:%.*]] = getelementptr inbounds i32, ptr [[ARR]], i64 [[TMP17]]
+; CHECK-NEXT:    [[TMP19:%.*]] = getelementptr inbounds i32, ptr [[TMP18]], i32 0
+; CHECK-NEXT:    store <4 x i32> <i32 65, i32 65, i32 65, i32 65>, ptr [[TMP19]], align 4
+; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
+; CHECK-NEXT:    [[TMP20:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
+; CHECK-NEXT:    br i1 [[TMP20]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK:       middle.block:
+; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[TMP0]], [[N_VEC]]
+; CHECK-NEXT:    [[CMO:%.*]] = sub i64 [[N_VEC]], 1
+; CHECK-NEXT:    [[IND_ESCAPE:%.*]] = add i64 1, [[CMO]]
+; CHECK-NEXT:    br i1 [[CMP_N]], label [[LOAD_VAL:%.*]], label [[SCALAR_PH]]
+; CHECK:       scalar.ph:
+; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ 1, [[PREHEADER]] ], [ 1, [[VECTOR_SCEVCHECK]] ]
+; CHECK-NEXT:    [[BC_RESUME_VAL2:%.*]] = phi i8 [ [[IND_END1]], [[MIDDLE_BLOCK]] ], [ 1, [[PREHEADER]] ], [ 1, [[VECTOR_SCEVCHECK]] ]
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[CONV:%.*]] = phi i64 [ [[CONV2:%.*]], [[LOOP]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]
+; CHECK-NEXT:    [[I:%.*]] = phi i8 [ [[INC:%.*]], [[LOOP]] ], [ [[BC_RESUME_VAL2]], [[SCALAR_PH]] ]
+; CHECK-NEXT:    [[SUB:%.*]] = add nsw i64 [[CONV]], -1
+; CHECK-NEXT:    [[PTR:%.*]] = getelementptr inbounds i32, ptr [[ARR]], i64 [[SUB]]
+; CHECK-NEXT:    store i32 65, ptr [[PTR]], align 4
+; CHECK-NEXT:    [[INC]] = add i8 [[I]], 1
+; CHECK-NEXT:    [[CONV2]] = zext i8 [[INC]] to i64
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[CONV2]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP2]], label [[LOOP]], label [[LOAD_VAL]], !llvm.loop [[LOOP4:![0-9]+]]
+; CHECK:       load_val:
+; CHECK-NEXT:    [[FINAL:%.*]] = phi i64 [ [[CONV]], [[LOOP]] ], [ [[IND_ESCAPE]], [[MIDDLE_BLOCK]] ]
+; CHECK-NEXT:    [[PTR2:%.*]] = getelementptr inbounds i32, ptr [[ARR]], i64 [[FINAL]]
+; CHECK-NEXT:    [[VAL:%.*]] = load i32, ptr [[PTR2]], align 4
+; CHECK-NEXT:    br label [[DONE]]
+; CHECK:       done:
+; CHECK-NEXT:    [[VALUE:%.*]] = phi i32 [ [[VAL]], [[LOAD_VAL]] ], [ 0, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    ret i32 [[VALUE]]
+;
+entry:
+  %cmp1 = icmp ugt i64 %n, 1
+  br i1 %cmp1, label %preheader, label %done
+
+preheader:
+  br label %loop
+
+loop:
+  %conv = phi i64 [ %conv2, %loop ], [ 1, %preheader ]
+  %i = phi i8 [ %inc, %loop ], [ 1, %preheader ]
+  %sub = add nsw i64 %conv, -1
+  %ptr = getelementptr inbounds i32, ptr %arr, i64 %sub
+  store i32 65, ptr %ptr, align 4
+  %inc = add i8 %i, 1
+  %conv2 = zext i8 %inc to i64
+  %cmp2 = icmp ult i64 %conv2, %n
+  br i1 %cmp2, label %loop, label %load_val, !llvm.loop !0
+
+load_val:
+  %final = phi i64 [ %conv, %loop ]
+  %ptr2 = getelementptr inbounds i32, ptr %arr, i64 %final
+  %val = load i32, ptr %ptr2, align 4
+  br label %done
+
+done:
+  %value = phi i32 [ %val, %load_val ], [ 0, %entry ]
+  ret i32 %value
+
+}
+
+!0 = distinct !{!0, !1, !2, !3}
+!1 = !{!"llvm.loop.unroll.disable"}
+!2 = !{!"llvm.loop.vectorize.predicate.enable", i1 true}
+!3 = !{!"llvm.loop.vectorize.enable", i1 true}
+;.
+; 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]]}
+;.



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