[llvm] LAA: add pre-commit tests for stride-versioning (PR #97570)
Ramkumar Ramachandra via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 3 06:01:11 PDT 2024
https://github.com/artagnon created https://github.com/llvm/llvm-project/pull/97570
Add tests for when the Stride is unknown and equal to TC, with different kinds of casts. In these cases, LAA should not speculate on Stride.
>From 86c6ad69ad21332a315f624052abc716d547a214 Mon Sep 17 00:00:00 2001
From: Ramkumar Ramachandra <ramkumar.ramachandra at codasip.com>
Date: Wed, 3 Jul 2024 13:48:48 +0100
Subject: [PATCH] LAA: add pre-commit tests for stride-versioning
Add tests for when the Stride is unknown and equal to TC, with different
kinds of casts. In these cases, LAA should not speculate on Stride.
---
.../LoopAccessAnalysis/symbolic-stride.ll | 181 ++++++++++++++++++
1 file changed, 181 insertions(+)
diff --git a/llvm/test/Analysis/LoopAccessAnalysis/symbolic-stride.ll b/llvm/test/Analysis/LoopAccessAnalysis/symbolic-stride.ll
index 7c1b11e22aef2..b14eb6d6aa3db 100644
--- a/llvm/test/Analysis/LoopAccessAnalysis/symbolic-stride.ll
+++ b/llvm/test/Analysis/LoopAccessAnalysis/symbolic-stride.ll
@@ -310,3 +310,184 @@ loop:
exit: ; preds = %loop
ret void
}
+
+; Check the scenario where we have an unknown Stride, which happens to also be
+; the loop iteration count. If we speculate Stride==1, it implies that the loop
+; will iterate no more than a single iteration.
+define i32 @unknown_stride_equalto_tc(i32 %N, ptr %A, ptr %B, i32 %i, i32 %j) {
+; CHECK-LABEL: 'unknown_stride_equalto_tc'
+; CHECK-NEXT: for.body:
+; CHECK-NEXT: Memory dependences are safe
+; CHECK-NEXT: Dependences:
+; CHECK-NEXT: Run-time memory checks:
+; CHECK-NEXT: Grouped accesses:
+; CHECK-EMPTY:
+; CHECK-NEXT: Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT: SCEV assumptions:
+; CHECK-EMPTY:
+; CHECK-NEXT: Expressions re-written:
+;
+entry:
+ %cmp8 = icmp eq i32 %N, 0
+ br i1 %cmp8, label %for.end, label %for.body.lr.ph
+
+for.body.lr.ph:
+ br label %for.body
+
+for.body:
+ %tmp.010 = phi i32 [ 0, %for.body.lr.ph ], [ %add1, %for.body ]
+ %k.09 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
+ %mul = mul i32 %k.09, %N
+ %add = add i32 %mul, %j
+ %arrayidx = getelementptr inbounds i16, ptr %B, i32 %add
+ %0 = load i16, ptr %arrayidx, align 2
+ %conv = sext i16 %0 to i32
+ %add1 = add nsw i32 %tmp.010, %conv
+ %inc = add nuw i32 %k.09, 1
+ %exitcond = icmp eq i32 %inc, %N
+ br i1 %exitcond, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:
+ %add1.lcssa = phi i32 [ %add1, %for.body ]
+ br label %for.end
+
+for.end:
+ %tmp.0.lcssa = phi i32 [ 0, %entry ], [ %add1.lcssa, %for.end.loopexit ]
+ ret i32 %tmp.0.lcssa
+}
+
+
+; Check the scenario where we have an unknown Stride, which happens to also be
+; the loop iteration count, but the TC is zero-extended from a narrower type.
+define i32 @unknown_stride_equalto_zext_tc(i16 zeroext %N, ptr %A, ptr %B, i32 %i, i32 %j) {
+; CHECK-LABEL: 'unknown_stride_equalto_zext_tc'
+; CHECK-NEXT: for.body:
+; CHECK-NEXT: Memory dependences are safe
+; CHECK-NEXT: Dependences:
+; CHECK-NEXT: Run-time memory checks:
+; CHECK-NEXT: Grouped accesses:
+; CHECK-EMPTY:
+; CHECK-NEXT: Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT: SCEV assumptions:
+; CHECK-EMPTY:
+; CHECK-NEXT: Expressions re-written:
+;
+entry:
+ %conv = zext i16 %N to i32
+ %cmp11 = icmp eq i16 %N, 0
+ br i1 %cmp11, label %for.end, label %for.body.lr.ph
+
+for.body.lr.ph:
+ br label %for.body
+
+for.body:
+ %tmp.013 = phi i32 [ 0, %for.body.lr.ph ], [ %add4, %for.body ]
+ %k.012 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
+ %mul = mul nuw i32 %k.012, %conv
+ %add = add i32 %mul, %j
+ %arrayidx = getelementptr inbounds i16, ptr %B, i32 %add
+ %0 = load i16, ptr %arrayidx, align 2
+ %conv3 = sext i16 %0 to i32
+ %add4 = add nsw i32 %tmp.013, %conv3
+ %inc = add nuw nsw i32 %k.012, 1
+ %exitcond = icmp eq i32 %inc, %conv
+ br i1 %exitcond, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:
+ %add4.lcssa = phi i32 [ %add4, %for.body ]
+ br label %for.end
+
+for.end:
+ %tmp.0.lcssa = phi i32 [ 0, %entry ], [ %add4.lcssa, %for.end.loopexit ]
+ ret i32 %tmp.0.lcssa
+}
+
+; Check the scenario where we have an unknown Stride, which happens to also be
+; the loop iteration count, but the TC is sign-extended from a narrower type.
+define i32 @unknown_stride_equalto_sext_tc(i16 %N, ptr %A, ptr %B, i32 %i, i32 %j) {
+; CHECK-LABEL: 'unknown_stride_equalto_sext_tc'
+; CHECK-NEXT: for.body:
+; CHECK-NEXT: Memory dependences are safe
+; CHECK-NEXT: Dependences:
+; CHECK-NEXT: Run-time memory checks:
+; CHECK-NEXT: Grouped accesses:
+; CHECK-EMPTY:
+; CHECK-NEXT: Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT: SCEV assumptions:
+; CHECK-EMPTY:
+; CHECK-NEXT: Expressions re-written:
+;
+entry:
+ %conv = sext i16 %N to i32
+ %cmp11 = icmp eq i16 %N, 0
+ br i1 %cmp11, label %for.end, label %for.body.lr.ph
+
+for.body.lr.ph:
+ br label %for.body
+
+for.body:
+ %tmp.013 = phi i32 [ 0, %for.body.lr.ph ], [ %add4, %for.body ]
+ %k.012 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
+ %mul = mul nuw i32 %k.012, %conv
+ %add = add i32 %mul, %j
+ %arrayidx = getelementptr inbounds i16, ptr %B, i32 %add
+ %0 = load i16, ptr %arrayidx, align 2
+ %conv3 = sext i16 %0 to i32
+ %add4 = add nsw i32 %tmp.013, %conv3
+ %inc = add nuw nsw i32 %k.012, 1
+ %exitcond = icmp eq i32 %inc, %conv
+ br i1 %exitcond, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:
+ %add4.lcssa = phi i32 [ %add4, %for.body ]
+ br label %for.end
+
+for.end:
+ %tmp.0.lcssa = phi i32 [ 0, %entry ], [ %add4.lcssa, %for.end.loopexit ]
+ ret i32 %tmp.0.lcssa
+}
+
+; Check the scenario where we have an unknown Stride, which happens to also be
+; the loop iteration count, but the TC is truncated from a wider type.
+define i32 @unknown_stride_equalto_trunc_tc(i64 %N, ptr %A, ptr %B, i32 %i, i32 %j) {
+; CHECK-LABEL: 'unknown_stride_equalto_trunc_tc'
+; CHECK-NEXT: for.body:
+; CHECK-NEXT: Memory dependences are safe
+; CHECK-NEXT: Dependences:
+; CHECK-NEXT: Run-time memory checks:
+; CHECK-NEXT: Grouped accesses:
+; CHECK-EMPTY:
+; CHECK-NEXT: Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT: SCEV assumptions:
+; CHECK-EMPTY:
+; CHECK-NEXT: Expressions re-written:
+;
+entry:
+ %conv = trunc i64 %N to i32
+ %cmp11 = icmp eq i64 %N, 0
+ br i1 %cmp11, label %for.end, label %for.body.lr.ph
+
+for.body.lr.ph:
+ br label %for.body
+
+for.body:
+ %tmp.013 = phi i32 [ 0, %for.body.lr.ph ], [ %add4, %for.body ]
+ %k.012 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
+ %mul = mul nuw i32 %k.012, %conv
+ %add = add i32 %mul, %j
+ %arrayidx = getelementptr inbounds i16, ptr %B, i32 %add
+ %0 = load i16, ptr %arrayidx, align 2
+ %conv3 = sext i16 %0 to i32
+ %add4 = add nsw i32 %tmp.013, %conv3
+ %inc = add nuw nsw i32 %k.012, 1
+ %exitcond = icmp eq i32 %inc, %conv
+ br i1 %exitcond, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:
+ %add4.lcssa = phi i32 [ %add4, %for.body ]
+ br label %for.end
+
+for.end:
+ %tmp.0.lcssa = phi i32 [ 0, %entry ], [ %add4.lcssa, %for.end.loopexit ]
+ ret i32 %tmp.0.lcssa
+}
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