forked from OSchip/llvm-project
ARM cost model: Add cost for gather/scather
Fixes a 35% degradation compared to unvectorized code in MiBench/automotive-susan and an equally serious regression on a private image processing benchmark. radar://14351991 llvm-svn: 186188
This commit is contained in:
Arnold Schwaighofer
parent
9da9a43af8
commit
da2b311865
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@ -426,6 +426,15 @@ unsigned ARMTTI::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
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}
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unsigned ARMTTI::getAddressComputationCost(Type *Ty, bool IsComplex) const {
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// Address computations in vectorized code with non-consecutive addresses will
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// likely result in more instructions compared to scalar code where the
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// computation can more often be merged into the index mode. The resulting
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// extra micro-ops can significantly decrease throughput.
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unsigned NumVectorInstToHideOverhead = 10;
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if (Ty->isVectorTy() && IsComplex)
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return NumVectorInstToHideOverhead;
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// In many cases the address computation is not merged into the instruction
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// addressing mode.
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return 1;
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@ -0,0 +1,88 @@
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; RUN: opt -loop-vectorize -mtriple=thumbv7s-apple-ios6.0.0 -S < %s | FileCheck %s
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target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32-S32"
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@kernel = global [512 x float] zeroinitializer, align 4
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@kernel2 = global [512 x float] zeroinitializer, align 4
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@kernel3 = global [512 x float] zeroinitializer, align 4
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@kernel4 = global [512 x float] zeroinitializer, align 4
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@src_data = global [1536 x float] zeroinitializer, align 4
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@r_ = global i8 0, align 4
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@g_ = global i8 0, align 4
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@b_ = global i8 0, align 4
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; We don't want to vectorize most loops containing gathers because they are
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; expensive. This function represents a point where vectorization starts to
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; become beneficial.
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; Make sure we are conservative and don't vectorize it.
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; CHECK-NOT: <2 x float>
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; CHECK-NOT: <4 x float>
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define void @_Z4testmm(i32 %size, i32 %offset) {
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entry:
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%cmp53 = icmp eq i32 %size, 0
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br i1 %cmp53, label %for.end, label %for.body.lr.ph
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for.body.lr.ph:
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br label %for.body
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for.body:
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%r.057 = phi float [ 0.000000e+00, %for.body.lr.ph ], [ %add10, %for.body ]
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%g.056 = phi float [ 0.000000e+00, %for.body.lr.ph ], [ %add20, %for.body ]
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%v.055 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
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%b.054 = phi float [ 0.000000e+00, %for.body.lr.ph ], [ %add30, %for.body ]
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%add = add i32 %v.055, %offset
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%mul = mul i32 %add, 3
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%arrayidx = getelementptr inbounds [1536 x float]* @src_data, i32 0, i32 %mul
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%0 = load float* %arrayidx, align 4
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%arrayidx2 = getelementptr inbounds [512 x float]* @kernel, i32 0, i32 %v.055
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%1 = load float* %arrayidx2, align 4
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%mul3 = fmul fast float %0, %1
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%arrayidx4 = getelementptr inbounds [512 x float]* @kernel2, i32 0, i32 %v.055
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%2 = load float* %arrayidx4, align 4
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%mul5 = fmul fast float %mul3, %2
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%arrayidx6 = getelementptr inbounds [512 x float]* @kernel3, i32 0, i32 %v.055
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%3 = load float* %arrayidx6, align 4
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%mul7 = fmul fast float %mul5, %3
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%arrayidx8 = getelementptr inbounds [512 x float]* @kernel4, i32 0, i32 %v.055
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%4 = load float* %arrayidx8, align 4
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%mul9 = fmul fast float %mul7, %4
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%add10 = fadd fast float %r.057, %mul9
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%arrayidx.sum = add i32 %mul, 1
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%arrayidx11 = getelementptr inbounds [1536 x float]* @src_data, i32 0, i32 %arrayidx.sum
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%5 = load float* %arrayidx11, align 4
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%mul13 = fmul fast float %1, %5
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%mul15 = fmul fast float %2, %mul13
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%mul17 = fmul fast float %3, %mul15
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%mul19 = fmul fast float %4, %mul17
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%add20 = fadd fast float %g.056, %mul19
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%arrayidx.sum52 = add i32 %mul, 2
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%arrayidx21 = getelementptr inbounds [1536 x float]* @src_data, i32 0, i32 %arrayidx.sum52
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%6 = load float* %arrayidx21, align 4
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%mul23 = fmul fast float %1, %6
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%mul25 = fmul fast float %2, %mul23
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%mul27 = fmul fast float %3, %mul25
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%mul29 = fmul fast float %4, %mul27
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%add30 = fadd fast float %b.054, %mul29
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%inc = add i32 %v.055, 1
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%exitcond = icmp ne i32 %inc, %size
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br i1 %exitcond, label %for.body, label %for.cond.for.end_crit_edge
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for.cond.for.end_crit_edge:
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%add30.lcssa = phi float [ %add30, %for.body ]
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%add20.lcssa = phi float [ %add20, %for.body ]
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%add10.lcssa = phi float [ %add10, %for.body ]
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%phitmp = fptoui float %add10.lcssa to i8
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%phitmp60 = fptoui float %add20.lcssa to i8
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%phitmp61 = fptoui float %add30.lcssa to i8
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br label %for.end
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for.end:
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%r.0.lcssa = phi i8 [ %phitmp, %for.cond.for.end_crit_edge ], [ 0, %entry ]
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%g.0.lcssa = phi i8 [ %phitmp60, %for.cond.for.end_crit_edge ], [ 0, %entry ]
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%b.0.lcssa = phi i8 [ %phitmp61, %for.cond.for.end_crit_edge ], [ 0, %entry ]
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store i8 %r.0.lcssa, i8* @r_, align 4
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store i8 %g.0.lcssa, i8* @g_, align 4
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store i8 %b.0.lcssa, i8* @b_, align 4
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ret void
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}
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