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https://github.com/RPCS3/llvm-mirror.git
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6f568d5434
Summary: When SCEVRewriteVisitor traverses the SCEV DAG, it may visit the same SCEV multiple times if this SCEV is referenced by multiple other SCEVs. This has exponential time complexity in the worst case. Memoizing the results will avoid re-visiting the same SCEV. Add a map to save the results, and override the visit function of SCEVVisitor. Now SCEVRewriteVisitor only visit each SCEV once and thus returns the same result for the same input SCEV. This patch fixes PR18606, PR18607. Reviewers: Sanjoy Das, Mehdi Amini, Michael Zolotukhin Differential Revision: https://reviews.llvm.org/D25810 llvm-svn: 284868
68 lines
2.5 KiB
LLVM
68 lines
2.5 KiB
LLVM
; RUN: opt -S -indvars < %s | FileCheck %s
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; CHECK: @main
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; CHECK: %mul.lcssa5 = phi i32 [ %a.promoted4, %entry ], [ %mul.30, %for.body3 ]
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; CEHCK: %mul = mul nsw i32 %mul.lcssa5, %mul.lcssa5
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; CHECK: %mul.30 = mul nsw i32 %mul.29, %mul.29
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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-unknown-linux-gnu"
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@a = local_unnamed_addr global i32 0, align 4
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@b = local_unnamed_addr global i32 0, align 4
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; Function Attrs: norecurse nounwind uwtable
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define i32 @main() local_unnamed_addr {
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entry:
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%a.promoted4 = load i32, i32* @a, align 4
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br label %for.cond1.preheader
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for.cond1.preheader: ; preds = %entry, %for.body3
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%mul.lcssa5 = phi i32 [ %a.promoted4, %entry ], [ %mul.30, %for.body3 ]
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%i.03 = phi i32 [ 0, %entry ], [ %inc5, %for.body3 ]
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br label %for.body3
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for.body3: ; preds = %for.cond1.preheader
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%mul = mul nsw i32 %mul.lcssa5, %mul.lcssa5
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%mul.1 = mul nsw i32 %mul, %mul
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%mul.2 = mul nsw i32 %mul.1, %mul.1
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%mul.3 = mul nsw i32 %mul.2, %mul.2
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%mul.4 = mul nsw i32 %mul.3, %mul.3
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%mul.5 = mul nsw i32 %mul.4, %mul.4
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%mul.6 = mul nsw i32 %mul.5, %mul.5
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%mul.7 = mul nsw i32 %mul.6, %mul.6
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%mul.8 = mul nsw i32 %mul.7, %mul.7
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%mul.9 = mul nsw i32 %mul.8, %mul.8
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%mul.10 = mul nsw i32 %mul.9, %mul.9
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%mul.11 = mul nsw i32 %mul.10, %mul.10
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%mul.12 = mul nsw i32 %mul.11, %mul.11
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%mul.13 = mul nsw i32 %mul.12, %mul.12
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%mul.14 = mul nsw i32 %mul.13, %mul.13
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%mul.15 = mul nsw i32 %mul.14, %mul.14
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%mul.16 = mul nsw i32 %mul.15, %mul.15
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%mul.17 = mul nsw i32 %mul.16, %mul.16
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%mul.18 = mul nsw i32 %mul.17, %mul.17
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%mul.19 = mul nsw i32 %mul.18, %mul.18
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%mul.20 = mul nsw i32 %mul.19, %mul.19
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%mul.21 = mul nsw i32 %mul.20, %mul.20
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%mul.22 = mul nsw i32 %mul.21, %mul.21
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%mul.23 = mul nsw i32 %mul.22, %mul.22
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%mul.24 = mul nsw i32 %mul.23, %mul.23
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%mul.25 = mul nsw i32 %mul.24, %mul.24
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%mul.26 = mul nsw i32 %mul.25, %mul.25
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%mul.27 = mul nsw i32 %mul.26, %mul.26
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%mul.28 = mul nsw i32 %mul.27, %mul.27
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%mul.29 = mul nsw i32 %mul.28, %mul.28
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%mul.30 = mul nsw i32 %mul.29, %mul.29
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%inc5 = add nuw nsw i32 %i.03, 1
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%exitcond = icmp ne i32 %inc5, 10
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br i1 %exitcond, label %for.cond1.preheader, label %for.end6
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for.end6: ; preds = %for.body3
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%mul.lcssa.lcssa = phi i32 [ %mul.30, %for.body3 ]
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%inc.lcssa.lcssa = phi i32 [ 31, %for.body3 ]
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store i32 %mul.lcssa.lcssa, i32* @a, align 4
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store i32 %inc.lcssa.lcssa, i32* @b, align 4
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ret i32 0
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}
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