befc952045
When the loop vectoriser encounters a known low trip count it tries to create a single predicated loop in order to get the benefit of vectorisation and eliminate the scalar tail. However, until now the vectoriser prevented the use of scalable vectors in this case due to concerns in the past about stability. I believe that tail-folded loops using scalable vectors are now sufficiently well tested that we can enable this. For the same reason I've also enabled it when optimising for code size too. Tests added here: Transforms/LoopVectorize/AArch64/sve-low-trip-count.ll Transforms/LoopVectorize/AArch64/sve-tail-folding-optsize.ll Transforms/LoopVectorize/RISCV/low-trip-count.ll Differential Revision: https://reviews.llvm.org/D121595
34 lines
1.8 KiB
LLVM
34 lines
1.8 KiB
LLVM
; RUN: opt -loop-vectorize -riscv-v-vector-bits-min=128 -scalable-vectorization=on -force-target-instruction-cost=1 -S < %s | FileCheck %s
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target triple = "riscv64"
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define void @trip5_i8(i8* noalias nocapture noundef %dst, i8* noalias nocapture noundef readonly %src) #0 {
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; CHECK-LABEL: @trip5_i8(
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; CHECK: vector.body:
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; CHECK: [[ACTIVE_LANE_MASK:%.*]] = icmp ule <vscale x 8 x i64> {{%.*}}, shufflevector (<vscale x 8 x i64> insertelement (<vscale x 8 x i64> poison, i64 4, i32 0), <vscale x 8 x i64> poison, <vscale x 8 x i32> zeroinitializer)
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; CHECK: {{%.*}} = call <vscale x 8 x i8> @llvm.masked.load.nxv8i8.p0nxv8i8(<vscale x 8 x i8>* {{%.*}}, i32 1, <vscale x 8 x i1> [[ACTIVE_LANE_MASK]], <vscale x 8 x i8> poison)
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; CHECK: {{%.*}} = call <vscale x 8 x i8> @llvm.masked.load.nxv8i8.p0nxv8i8(<vscale x 8 x i8>* {{%.*}}, i32 1, <vscale x 8 x i1> [[ACTIVE_LANE_MASK]], <vscale x 8 x i8> poison)
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; CHECK: call void @llvm.masked.store.nxv8i8.p0nxv8i8(<vscale x 8 x i8> {{%.*}}, <vscale x 8 x i8>* {{%.*}}, i32 1, <vscale x 8 x i1> [[ACTIVE_LANE_MASK]])
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;
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entry:
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br label %for.body
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for.body: ; preds = %entry, %for.body
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%i.08 = phi i64 [ 0, %entry ], [ %inc, %for.body ]
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%arrayidx = getelementptr inbounds i8, i8* %src, i64 %i.08
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%0 = load i8, i8* %arrayidx, align 1
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%mul = shl i8 %0, 1
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%arrayidx1 = getelementptr inbounds i8, i8* %dst, i64 %i.08
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%1 = load i8, i8* %arrayidx1, align 1
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%add = add i8 %mul, %1
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store i8 %add, i8* %arrayidx1, align 1
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%inc = add nuw nsw i64 %i.08, 1
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%exitcond.not = icmp eq i64 %inc, 5
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br i1 %exitcond.not, label %for.end, label %for.body
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for.end: ; preds = %for.body
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ret void
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}
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attributes #0 = { "target-features"="+v,+d" }
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