From 1ca1fcaa5b4c75a65a202badfd5df8240a36ca0f Mon Sep 17 00:00:00 2001 From: "Arch D. Robison" Date: Mon, 25 Apr 2016 22:22:39 +0000 Subject: [PATCH] Optimize store of "bitcast" from vector to aggregate. This patch is what was the "instcombine" portion of D14185, with an additional test added (see julia_pseudovec in test/Transforms/InstCombine/insert-val-extract-elem.ll). The patch causes instcombine to replace sequences of extractelement-insertvalue-store that act essentially like a bitcast followed by a store. Differential review: http://reviews.llvm.org/D14260 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267482 91177308-0d34-0410-b5e6-96231b3b80d8 Alpine maintainer notes: - Updated for llvm 3.8.1. - This patch replaces llvm-D14260.patch from Julia. --- .../InstCombine/InstCombineLoadStoreAlloca.cpp | 60 ++++++++++++++++++ .../InstCombine/insert-val-extract-elem.ll | 74 ++++++++++++++++++++++ 2 files changed, 134 insertions(+) create mode 100644 test/Transforms/InstCombine/insert-val-extract-elem.ll diff --git a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index 96f0908..0ee6045 100644 --- a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -913,6 +913,61 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) { return nullptr; } +/// \brief Look for extractelement/insertvalue sequence that acts like a bitcast. +/// +/// \returns underlying value that was "cast", or nullptr otherwise. +/// +/// For example, if we have: +/// +/// %E0 = extractelement <2 x double> %U, i32 0 +/// %V0 = insertvalue [2 x double] undef, double %E0, 0 +/// %E1 = extractelement <2 x double> %U, i32 1 +/// %V1 = insertvalue [2 x double] %V0, double %E1, 1 +/// +/// and the layout of a <2 x double> is isomorphic to a [2 x double], +/// then %V1 can be safely approximated by a conceptual "bitcast" of %U. +/// Note that %U may contain non-undef values where %V1 has undef. +static Value *likeBitCastFromVector(InstCombiner &IC, Value *V) { + Value *U = nullptr; + while (auto *IV = dyn_cast(V)) { + auto *E = dyn_cast(IV->getInsertedValueOperand()); + if (!E) + return nullptr; + auto *W = E->getVectorOperand(); + if (!U) + U = W; + else if (U != W) + return nullptr; + auto *CI = dyn_cast(E->getIndexOperand()); + if (!CI || IV->getNumIndices() != 1 || CI->getZExtValue() != *IV->idx_begin()) + return nullptr; + V = IV->getAggregateOperand(); + } + if (!isa(V) ||!U) + return nullptr; + + auto *UT = cast(U->getType()); + auto *VT = V->getType(); + // Check that types UT and VT are bitwise isomorphic. + const auto &DL = IC.getDataLayout(); + if (DL.getTypeStoreSizeInBits(UT) != DL.getTypeStoreSizeInBits(VT)) { + return nullptr; + } + if (auto *AT = dyn_cast(VT)) { + if (AT->getNumElements() != UT->getNumElements()) + return nullptr; + } else { + auto *ST = cast(VT); + if (ST->getNumElements() != UT->getNumElements()) + return nullptr; + for (const auto *EltT : ST->elements()) { + if (EltT != UT->getElementType()) + return nullptr; + } + } + return U; +} + /// \brief Combine stores to match the type of value being stored. /// /// The core idea here is that the memory does not have any intrinsic type and @@ -924,6 +979,11 @@ return true; } + if (Value *U = likeBitCastFromVector(IC, V)) { + combineStoreToNewValue(IC, SI, U); + return true; + } + // FIXME: We should also canonicalize loads of vectors when their elements are // cast to other types. return false; diff --git a/test/Transforms/InstCombine/insert-val-extract-elem.ll b/test/Transforms/InstCombine/insert-val-extract-elem.ll new file mode 100644 index 0000000..db7b403 --- /dev/null +++ b/test/Transforms/InstCombine/insert-val-extract-elem.ll @@ -0,0 +1,74 @@ +; RUN: opt -S -instcombine %s | FileCheck %s + +; CHECK-LABEL: julia_2xdouble +; CHECK-NOT: insertvalue +; CHECK-NOT: extractelement +; CHECK: store <2 x double> +define void @julia_2xdouble([2 x double]* sret, <2 x double>*) { +top: + %x = load <2 x double>, <2 x double>* %1 + %x0 = extractelement <2 x double> %x, i32 0 + %i0 = insertvalue [2 x double] undef, double %x0, 0 + %x1 = extractelement <2 x double> %x, i32 1 + %i1 = insertvalue [2 x double] %i0, double %x1, 1 + store [2 x double] %i1, [2 x double]* %0, align 4 + ret void +} + +; Test with two inserts to the same index +; CHECK-LABEL: julia_2xi64 +; CHECK-NOT: insertvalue +; CHECK-NOT: extractelement +; CHECK: store <2 x i64> +define void @julia_2xi64([2 x i64]* sret, <2 x i64>*) { +top: + %x = load <2 x i64>, <2 x i64>* %1 + %x0 = extractelement <2 x i64> %x, i32 1 + %i0 = insertvalue [2 x i64] undef, i64 %x0, 0 + %x1 = extractelement <2 x i64> %x, i32 1 + %i1 = insertvalue [2 x i64] %i0, i64 %x1, 1 + %x2 = extractelement <2 x i64> %x, i32 0 + %i2 = insertvalue [2 x i64] %i1, i64 %x2, 0 + store [2 x i64] %i2, [2 x i64]* %0, align 4 + ret void +} + +; CHECK-LABEL: julia_4xfloat +; CHECK-NOT: insertvalue +; CHECK-NOT: extractelement +; CHECK: store <4 x float> +define void @julia_4xfloat([4 x float]* sret, <4 x float>*) { +top: + %x = load <4 x float>, <4 x float>* %1 + %x0 = extractelement <4 x float> %x, i32 0 + %i0 = insertvalue [4 x float] undef, float %x0, 0 + %x1 = extractelement <4 x float> %x, i32 1 + %i1 = insertvalue [4 x float] %i0, float %x1, 1 + %x2 = extractelement <4 x float> %x, i32 2 + %i2 = insertvalue [4 x float] %i1, float %x2, 2 + %x3 = extractelement <4 x float> %x, i32 3 + %i3 = insertvalue [4 x float] %i2, float %x3, 3 + store [4 x float] %i3, [4 x float]* %0, align 4 + ret void +} + +%pseudovec = type { float, float, float, float } + +; CHECK-LABEL: julia_pseudovec +; CHECK-NOT: insertvalue +; CHECK-NOT: extractelement +; CHECK: store <4 x float> +define void @julia_pseudovec(%pseudovec* sret, <4 x float>*) { +top: + %x = load <4 x float>, <4 x float>* %1 + %x0 = extractelement <4 x float> %x, i32 0 + %i0 = insertvalue %pseudovec undef, float %x0, 0 + %x1 = extractelement <4 x float> %x, i32 1 + %i1 = insertvalue %pseudovec %i0, float %x1, 1 + %x2 = extractelement <4 x float> %x, i32 2 + %i2 = insertvalue %pseudovec %i1, float %x2, 2 + %x3 = extractelement <4 x float> %x, i32 3 + %i3 = insertvalue %pseudovec %i2, float %x3, 3 + store %pseudovec %i3, %pseudovec* %0, align 4 + ret void +}