From 082e33ac8c6bc2fce772d768b00ef83935977365 Mon Sep 17 00:00:00 2001 From: Nikolai Bozhenov Date: Fri, 20 Oct 2017 10:08:47 +0000 Subject: [PATCH] [ValueTracking] Enabling ValueTracking patch by default (recommit #2 after checking for timeout issue). The original patch was an improvement to IR ValueTracking on non-negative integers. It has been checked in to trunk (D18777, r284022). But was disabled by default due to performance regressions. Perf impact has improved. The patch would be enabled by default. Reviewers: reames, hfinkel Differential Revision: https://reviews.llvm.org/D34101 Patch by: Olga Chupina git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316208 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ValueTracking.cpp | 9 --------- test/Transforms/LoopUnroll/runtime-unroll-remainder.ll | 2 +- 2 files changed, 1 insertion(+), 10 deletions(-) diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp index 225d0649c2e..750e6bd3eb5 100644 --- a/lib/Analysis/ValueTracking.cpp +++ b/lib/Analysis/ValueTracking.cpp @@ -83,12 +83,6 @@ const unsigned MaxDepth = 6; static cl::opt 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 -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) { @@ -1289,9 +1283,6 @@ static void computeKnownBitsFromOperator(const Operator *I, KnownBits &Known, Known.Zero.setLowBits(std::min(Known2.countMinTrailingZeros(), Known3.countMinTrailingZeros())); - if (DontImproveNonNegativePhiBits) - break; - auto *OverflowOp = dyn_cast(LU); if (OverflowOp && OverflowOp->hasNoSignedWrap()) { // If initial value of recurrence is nonnegative, and we are adding diff --git a/test/Transforms/LoopUnroll/runtime-unroll-remainder.ll b/test/Transforms/LoopUnroll/runtime-unroll-remainder.ll index ac97ce3dc1e..b85e09bc3bc 100644 --- a/test/Transforms/LoopUnroll/runtime-unroll-remainder.ll +++ b/test/Transforms/LoopUnroll/runtime-unroll-remainder.ll @@ -47,7 +47,7 @@ for.cond.cleanup: ; CHECK: or i64 [[INDVAR0]], 1 ; CHECK: or i64 [[INDVAR0]], 2 ; CHECK: or i64 [[INDVAR0]], 3 -; CHECK: add nsw i64 [[INDVAR0]], 4 +; CHECK: add nuw nsw i64 [[INDVAR0]], 4 ; CHECK: [[SUB:%[a-z.0-9]+]] = add i64 [[ITER]], -4 ; CHECK: [[ITER_CMP:%[a-z.0-9]+]] = icmp eq i64 [[SUB]], 0 ; CHECK: br i1 [[ITER_CMP]], label %[[LOOP_EXIT:.*]], label %for.body -- 2.11.0