From c04d241d13820b33224b5cbd89a427fc08e5d1d9 Mon Sep 17 00:00:00 2001 From: Arnold Schwaighofer Date: Tue, 29 Oct 2013 01:33:57 +0000 Subject: [PATCH] ARM cost model: Unaligned vectorized double stores are expensive Updated a test case that assumed that <2 x double> would vectorize to use <4 x float>. radar://15338229 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193574 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARMTargetTransformInfo.cpp | 15 ++++++++++++++ .../LoopVectorize/ARM/width-detect.ll | 18 ++++++++--------- test/Transforms/SLPVectorizer/ARM/memory.ll | 20 +++++++++++++++++++ 3 files changed, 44 insertions(+), 9 deletions(-) create mode 100644 test/Transforms/SLPVectorizer/ARM/memory.ll diff --git a/lib/Target/ARM/ARMTargetTransformInfo.cpp b/lib/Target/ARM/ARMTargetTransformInfo.cpp index 86b6215f09e..6bbb38facc2 100644 --- a/lib/Target/ARM/ARMTargetTransformInfo.cpp +++ b/lib/Target/ARM/ARMTargetTransformInfo.cpp @@ -129,6 +129,9 @@ public: unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueKind Op1Info = OK_AnyValue, OperandValueKind Op2Info = OK_AnyValue) const; + + unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment, + unsigned AddressSpace) const; /// @} }; @@ -540,3 +543,15 @@ unsigned ARMTTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueK return Cost; } +unsigned ARMTTI::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment, + unsigned AddressSpace) const { + std::pair LT = TLI->getTypeLegalizationCost(Src); + + if (Src->isVectorTy() && Alignment != 16 && + Src->getVectorElementType()->isDoubleTy()) { + // Unaligned loads/stores are extremely inefficient. + // We need 4 uops for vst.1/vld.1 vs 1uop for vldr/vstr. + return LT.first * 4; + } + return LT.first; +} diff --git a/test/Transforms/LoopVectorize/ARM/width-detect.ll b/test/Transforms/LoopVectorize/ARM/width-detect.ll index c0795b6a79a..99d7fa75ee3 100644 --- a/test/Transforms/LoopVectorize/ARM/width-detect.ll +++ b/test/Transforms/LoopVectorize/ARM/width-detect.ll @@ -3,27 +3,27 @@ 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" target triple = "thumbv7-apple-ios3.0.0" -;CHECK:foo_F64 -;CHECK: <2 x double> +;CHECK:foo_F32 +;CHECK: <4 x float> ;CHECK:ret -define double @foo_F64(double* nocapture %A, i32 %n) nounwind uwtable readonly ssp { +define float @foo_F32(float* nocapture %A, i32 %n) nounwind uwtable readonly ssp { %1 = icmp sgt i32 %n, 0 br i1 %1, label %.lr.ph, label %._crit_edge .lr.ph: ; preds = %0, %.lr.ph %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %0 ] - %prod.01 = phi double [ %4, %.lr.ph ], [ 0.000000e+00, %0 ] - %2 = getelementptr inbounds double* %A, i64 %indvars.iv - %3 = load double* %2, align 8 - %4 = fmul fast double %prod.01, %3 + %prod.01 = phi float [ %4, %.lr.ph ], [ 0.000000e+00, %0 ] + %2 = getelementptr inbounds float* %A, i64 %indvars.iv + %3 = load float* %2, align 8 + %4 = fmul fast float %prod.01, %3 %indvars.iv.next = add i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %n br i1 %exitcond, label %._crit_edge, label %.lr.ph ._crit_edge: ; preds = %.lr.ph, %0 - %prod.0.lcssa = phi double [ 0.000000e+00, %0 ], [ %4, %.lr.ph ] - ret double %prod.0.lcssa + %prod.0.lcssa = phi float [ 0.000000e+00, %0 ], [ %4, %.lr.ph ] + ret float %prod.0.lcssa } ;CHECK:foo_I8 diff --git a/test/Transforms/SLPVectorizer/ARM/memory.ll b/test/Transforms/SLPVectorizer/ARM/memory.ll new file mode 100644 index 00000000000..383c808d21c --- /dev/null +++ b/test/Transforms/SLPVectorizer/ARM/memory.ll @@ -0,0 +1,20 @@ +; RUN: opt < %s -basicaa -slp-vectorizer -S -mtriple=thumbv7-apple-ios3.0.0 -mcpu=swift | FileCheck %s + +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" + +; On swift unaligned <2 x double> stores need 4uops and it is there for cheaper +; to do this scalar. + +; CHECK-LABEL: expensive_double_store +; CHECK-NOT: load <2 x double> +; CHECK-NOT: store <2 x double> +define void @expensive_double_store(double* noalias %dst, double* noalias %src, i64 %count) { +entry: + %0 = load double* %src, align 8 + store double %0, double* %dst, align 8 + %arrayidx2 = getelementptr inbounds double* %src, i64 1 + %1 = load double* %arrayidx2, align 8 + %arrayidx3 = getelementptr inbounds double* %dst, i64 1 + store double %1, double* %arrayidx3, align 8 + ret void +} -- 2.34.1