X86 cost model: Add cost for vectorized gather/scather

radar://14351991

llvm-svn: 186189
This commit is contained in:
Arnold Schwaighofer 2013-07-12 19:16:07 +00:00
parent da2b311865
commit 6042a261b8
2 changed files with 101 additions and 0 deletions

View File

@ -100,6 +100,8 @@ public:
unsigned Alignment,
unsigned AddressSpace) const;
virtual unsigned getAddressComputationCost(Type *PtrTy, bool IsComplex) const;
/// @}
};
@ -598,3 +600,16 @@ unsigned X86TTI::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
return Cost;
}
unsigned X86TTI::getAddressComputationCost(Type *Ty, bool IsComplex) const {
// Address computations in vectorized code with non-consecutive addresses will
// likely result in more instructions compared to scalar code where the
// computation can more often be merged into the index mode. The resulting
// extra micro-ops can significantly decrease throughput.
unsigned NumVectorInstToHideOverhead = 10;
if (Ty->isVectorTy() && IsComplex)
return NumVectorInstToHideOverhead;
return TargetTransformInfo::getAddressComputationCost(Ty, IsComplex);
}

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@ -0,0 +1,86 @@
; RUN: opt -loop-vectorize -mtriple=x86_64-apple-macosx -S -mcpu=corei7-avx < %s | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
@kernel = global [512 x float] zeroinitializer, align 16
@kernel2 = global [512 x float] zeroinitializer, align 16
@kernel3 = global [512 x float] zeroinitializer, align 16
@kernel4 = global [512 x float] zeroinitializer, align 16
@src_data = global [1536 x float] zeroinitializer, align 16
@r_ = global i8 0, align 1
@g_ = global i8 0, align 1
@b_ = global i8 0, align 1
; We don't want to vectorize most loops containing gathers because they are
; expensive. This function represents a point where vectorization starts to
; become beneficial.
; Make sure we are conservative and don't vectorize it.
; CHECK-NOT: x float>
define void @_Z4testmm(i64 %size, i64 %offset) {
entry:
%cmp53 = icmp eq i64 %size, 0
br i1 %cmp53, label %for.end, label %for.body.lr.ph
for.body.lr.ph:
br label %for.body
for.body:
%r.057 = phi float [ 0.000000e+00, %for.body.lr.ph ], [ %add10, %for.body ]
%g.056 = phi float [ 0.000000e+00, %for.body.lr.ph ], [ %add20, %for.body ]
%v.055 = phi i64 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
%b.054 = phi float [ 0.000000e+00, %for.body.lr.ph ], [ %add30, %for.body ]
%add = add i64 %v.055, %offset
%mul = mul i64 %add, 3
%arrayidx = getelementptr inbounds [1536 x float]* @src_data, i64 0, i64 %mul
%0 = load float* %arrayidx, align 4
%arrayidx2 = getelementptr inbounds [512 x float]* @kernel, i64 0, i64 %v.055
%1 = load float* %arrayidx2, align 4
%mul3 = fmul fast float %0, %1
%arrayidx4 = getelementptr inbounds [512 x float]* @kernel2, i64 0, i64 %v.055
%2 = load float* %arrayidx4, align 4
%mul5 = fmul fast float %mul3, %2
%arrayidx6 = getelementptr inbounds [512 x float]* @kernel3, i64 0, i64 %v.055
%3 = load float* %arrayidx6, align 4
%mul7 = fmul fast float %mul5, %3
%arrayidx8 = getelementptr inbounds [512 x float]* @kernel4, i64 0, i64 %v.055
%4 = load float* %arrayidx8, align 4
%mul9 = fmul fast float %mul7, %4
%add10 = fadd fast float %r.057, %mul9
%arrayidx.sum = add i64 %mul, 1
%arrayidx11 = getelementptr inbounds [1536 x float]* @src_data, i64 0, i64 %arrayidx.sum
%5 = load float* %arrayidx11, align 4
%mul13 = fmul fast float %1, %5
%mul15 = fmul fast float %2, %mul13
%mul17 = fmul fast float %3, %mul15
%mul19 = fmul fast float %4, %mul17
%add20 = fadd fast float %g.056, %mul19
%arrayidx.sum52 = add i64 %mul, 2
%arrayidx21 = getelementptr inbounds [1536 x float]* @src_data, i64 0, i64 %arrayidx.sum52
%6 = load float* %arrayidx21, align 4
%mul23 = fmul fast float %1, %6
%mul25 = fmul fast float %2, %mul23
%mul27 = fmul fast float %3, %mul25
%mul29 = fmul fast float %4, %mul27
%add30 = fadd fast float %b.054, %mul29
%inc = add i64 %v.055, 1
%exitcond = icmp ne i64 %inc, %size
br i1 %exitcond, label %for.body, label %for.cond.for.end_crit_edge
for.cond.for.end_crit_edge:
%add30.lcssa = phi float [ %add30, %for.body ]
%add20.lcssa = phi float [ %add20, %for.body ]
%add10.lcssa = phi float [ %add10, %for.body ]
%phitmp = fptoui float %add10.lcssa to i8
%phitmp60 = fptoui float %add20.lcssa to i8
%phitmp61 = fptoui float %add30.lcssa to i8
br label %for.end
for.end:
%r.0.lcssa = phi i8 [ %phitmp, %for.cond.for.end_crit_edge ], [ 0, %entry ]
%g.0.lcssa = phi i8 [ %phitmp60, %for.cond.for.end_crit_edge ], [ 0, %entry ]
%b.0.lcssa = phi i8 [ %phitmp61, %for.cond.for.end_crit_edge ], [ 0, %entry ]
store i8 %r.0.lcssa, i8* @r_, align 1
store i8 %g.0.lcssa, i8* @g_, align 1
store i8 %b.0.lcssa, i8* @b_, align 1
ret void
}