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| author | Nikolai Bozhenov <nikolai.bozhenov@intel.com> | 2017-06-28 12:15:13 +0000 |
|---|---|---|
| committer | Nikolai Bozhenov <nikolai.bozhenov@intel.com> | 2017-06-28 12:15:13 +0000 |
| commit | 6710ba07c7ce84c4dbeb19d7dbbf1dada193e588 (patch) | |
| tree | a1a496761c37711a2d2f81758478af47e1cfc9b9 | |
| parent | d5b59cf91466c1718fa329dd6d893aafc57c9771 (diff) | |
| download | bcm5719-llvm-6710ba07c7ce84c4dbeb19d7dbbf1dada193e588.tar.gz bcm5719-llvm-6710ba07c7ce84c4dbeb19d7dbbf1dada193e588.zip | |
Revert r306528
llvm-svn: 306536
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 9 | ||||
| -rw-r--r-- | llvm/test/Transforms/BBVectorize/loop1.ll | 2 |
2 files changed, 10 insertions, 1 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 5e9f8cc8d1b..fd519e2ad5c 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -54,6 +54,12 @@ const unsigned MaxDepth = 6; static cl::opt<unsigned> DomConditionsMaxUses("dom-conditions-max-uses", cl::Hidden, cl::init(20)); +// This optimization is known to cause performance regressions is some cases, +// keep it under a temporary flag for now. +static cl::opt<bool> +DontImproveNonNegativePhiBits("dont-improve-non-negative-phi-bits", + cl::Hidden, cl::init(true)); + /// Returns the bitwidth of the given scalar or pointer type. For vector types, /// returns the element type's bitwidth. static unsigned getBitWidth(Type *Ty, const DataLayout &DL) { @@ -1292,6 +1298,9 @@ static void computeKnownBitsFromOperator(const Operator *I, KnownBits &Known, Known.Zero.setLowBits(std::min(Known2.countMinTrailingZeros(), Known3.countMinTrailingZeros())); + if (DontImproveNonNegativePhiBits) + break; + auto *OverflowOp = dyn_cast<OverflowingBinaryOperator>(LU); if (OverflowOp && OverflowOp->hasNoSignedWrap()) { // If initial value of recurrence is nonnegative, and we are adding diff --git a/llvm/test/Transforms/BBVectorize/loop1.ll b/llvm/test/Transforms/BBVectorize/loop1.ll index 1b101e04833..8ff5953cf46 100644 --- a/llvm/test/Transforms/BBVectorize/loop1.ll +++ b/llvm/test/Transforms/BBVectorize/loop1.ll @@ -1,7 +1,7 @@ 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" target triple = "x86_64-unknown-linux-gnu" ; RUN: opt < %s -bb-vectorize -bb-vectorize-req-chain-depth=3 -bb-vectorize-ignore-target-info -instcombine -gvn -S | FileCheck %s -; RUN: opt < %s -basicaa -loop-unroll -unroll-threshold=45 -unroll-partial-threshold=45 -unroll-allow-partial -bb-vectorize -bb-vectorize-req-chain-depth=3 -bb-vectorize-ignore-target-info -instcombine -gvn -S | FileCheck %s -check-prefix=CHECK-UNRL +; RUN: opt < %s -dont-improve-non-negative-phi-bits=false -basicaa -loop-unroll -unroll-threshold=45 -unroll-partial-threshold=45 -unroll-allow-partial -bb-vectorize -bb-vectorize-req-chain-depth=3 -bb-vectorize-ignore-target-info -instcombine -gvn -S | FileCheck %s -check-prefix=CHECK-UNRL ; The second check covers the use of alias analysis (with loop unrolling). define void @test1(double* noalias %out, double* noalias %in1, double* noalias %in2) nounwind uwtable { |
