From: Lawrence Hu Date: Tue, 10 May 2016 21:11:09 +0000 (+0000) Subject: Revert r26084: Enable loopreroll for sext of loop control only IV X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0b382412f7218af82a9281551ba2e6417e198882;p=llvm Revert r26084: Enable loopreroll for sext of loop control only IV git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269119 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Transforms/Scalar/LoopRerollPass.cpp b/lib/Transforms/Scalar/LoopRerollPass.cpp index 2c08ee68871..cebb2f936fa 100644 --- a/lib/Transforms/Scalar/LoopRerollPass.cpp +++ b/lib/Transforms/Scalar/LoopRerollPass.cpp @@ -512,11 +512,11 @@ static const SCEVConstant *getIncrmentFactorSCEV(ScalarEvolution *SE, // Check if an IV is only used to control the loop. There are two cases: // 1. It only has one use which is loop increment, and the increment is only -// used by comparison and the PHI (could has sext with nsw in between), and the -// comparison is only used by branch. +// used by comparison and the PHI, and the comparison is only used by branch. // 2. It is used by loop increment and the comparison, the loop increment is // only used by the PHI, and the comparison is used only by the branch. bool LoopReroll::isLoopControlIV(Loop *L, Instruction *IV) { + unsigned IVUses = IV->getNumUses(); if (IVUses != 2 && IVUses != 1) return false; @@ -551,17 +551,9 @@ bool LoopReroll::isLoopControlIV(Loop *L, Instruction *IV) { if (PN != IV) return false; } - // Must be a CMP or an ext (of a value with nsw) then CMP - else { - Instruction *UUser = dyn_cast(UU); - // Skip SExt if we are extending an nsw value - // TODO: Allow ZExt too - if (BO->hasNoSignedWrap() && UUser && UUser->getNumUses() == 1 && - isa(UUser)) - UUser = dyn_cast(*(UUser->user_begin())); - if (!isCompareUsedByBranch(UUser)) - return false; - } + // Must be a CMP + else if (!isCompareUsedByBranch(dyn_cast(UU))) + return false; } } else return false; @@ -1169,11 +1161,6 @@ bool LoopReroll::DAGRootTracker::validate(ReductionTracker &Reductions) { Instruction *UUser = dyn_cast(UU); // UUser could be compare, PHI or branch Uses[UUser].set(IL_All); - // Skip SExt - if (isa(UUser)) { - UUser = dyn_cast(*(UUser->user_begin())); - Uses[UUser].set(IL_All); - } // Is UUser a compare instruction? if (UU->hasOneUse()) { Instruction *BI = dyn_cast(*UUser->user_begin()); @@ -1515,6 +1502,8 @@ void LoopReroll::DAGRootTracker::replaceIV(Instruction *Inst, if (NeedNewIV) ICSCEV = SE->getMulExpr(IterCount, SE->getConstant(IterCount->getType(), Scale)); + else + ICSCEV = RealIVSCEV->evaluateAtIteration(IterCount, *SE); // Iteration count SCEV minus or plus 1 const SCEV *MinusPlus1SCEV = @@ -1526,25 +1515,17 @@ void LoopReroll::DAGRootTracker::replaceIV(Instruction *Inst, const SCEV *ICMinusPlus1SCEV = SE->getMinusSCEV(ICSCEV, MinusPlus1SCEV); // Iteration count minus 1 - Instruction *InsertPtr = nullptr; + Value *ICMinusPlus1 = nullptr; if (isa(ICMinusPlus1SCEV)) { - InsertPtr = BI; + ICMinusPlus1 = + Expander.expandCodeFor(ICMinusPlus1SCEV, NewIV->getType(), BI); } else { BasicBlock *Preheader = L->getLoopPreheader(); if (!Preheader) Preheader = InsertPreheaderForLoop(L, DT, LI, PreserveLCSSA); - InsertPtr = Preheader->getTerminator(); - } - - if (!isa(NewIV->getType()) && NeedNewIV && - (SE->getTypeSizeInBits(NewIV->getType()) < - SE->getTypeSizeInBits(ICMinusPlus1SCEV->getType()))) { - IRBuilder<> Builder(BI); - Builder.SetCurrentDebugLocation(BI->getDebugLoc()); - NewIV = Builder.CreateSExt(NewIV, ICMinusPlus1SCEV->getType()); + ICMinusPlus1 = Expander.expandCodeFor( + ICMinusPlus1SCEV, NewIV->getType(), Preheader->getTerminator()); } - Value *ICMinusPlus1 = Expander.expandCodeFor( - ICMinusPlus1SCEV, NewIV->getType(), InsertPtr); Value *Cond = new ICmpInst(BI, CmpInst::ICMP_EQ, NewIV, ICMinusPlus1, "exitcond"); @@ -1724,7 +1705,6 @@ bool LoopReroll::runOnLoop(Loop *L, LPPassManager &LPM) { const SCEV *LIBETC = SE->getBackedgeTakenCount(L); const SCEV *IterCount = SE->getAddExpr(LIBETC, SE->getOne(LIBETC->getType())); - DEBUG(dbgs() << "\n Before Reroll:\n" << *(L->getHeader()) << "\n"); DEBUG(dbgs() << "LRR: iteration count = " << *IterCount << "\n"); // First, we need to find the induction variable with respect to which we can @@ -1751,7 +1731,6 @@ bool LoopReroll::runOnLoop(Loop *L, LPPassManager &LPM) { Changed = true; break; } - DEBUG(dbgs() << "\n After Reroll:\n" << *(L->getHeader()) << "\n"); // Trip count of L has changed so SE must be re-evaluated. if (Changed) diff --git a/test/Transforms/LoopReroll/indvar_with_ext.ll b/test/Transforms/LoopReroll/indvar_with_ext.ll deleted file mode 100644 index 7aae61433ae..00000000000 --- a/test/Transforms/LoopReroll/indvar_with_ext.ll +++ /dev/null @@ -1,186 +0,0 @@ -; RUN: opt -S -loop-reroll %s | FileCheck %s -target triple = "aarch64--linux-gnu" - -define void @test(i32 %n, float* %arrayidx200, float* %arrayidx164, float* %arrayidx172) { -entry: - %rem.i = srem i32 %n, 4 - %t22 = load float, float* %arrayidx172, align 4 - %cmp.9 = icmp eq i32 %n, 0 - %t7 = sext i32 %n to i64 - br i1 %cmp.9, label %while.end, label %while.body.preheader - -while.body.preheader: - br label %while.body - -while.body: -;CHECK-LABEL: while.body: -;CHECK-NEXT: %indvars.iv.i423 = phi i64 [ %indvars.iv.next.i424, %while.body ], [ 0, %while.body.preheader ] -;CHECK-NEXT: [[T1:%[0-9]+]] = trunc i64 %indvars.iv.i423 to i32 -;CHECK-NEXT: %arrayidx62.i = getelementptr inbounds float, float* %arrayidx200, i64 %indvars.iv.i423 -;CHECK-NEXT: %t1 = load float, float* %arrayidx62.i, align 4 -;CHECK-NEXT: %arrayidx64.i = getelementptr inbounds float, float* %arrayidx164, i64 %indvars.iv.i423 -;CHECK-NEXT: %t2 = load float, float* %arrayidx64.i, align 4 -;CHECK-NEXT: %mul65.i = fmul fast float %t2, %t22 -;CHECK-NEXT: %add66.i = fadd fast float %mul65.i, %t1 -;CHECK-NEXT: store float %add66.i, float* %arrayidx62.i, align 4 -;CHECK-NEXT: %indvars.iv.next.i424 = add i64 %indvars.iv.i423, 1 -;CHECK-NEXT: [[T2:%[0-9]+]] = sext i32 [[T1]] to i64 -;CHECK-NEXT: %exitcond = icmp eq i64 [[T2]], %{{[0-9]+}} -;CHECK-NEXT: br i1 %exitcond, label %while.end.loopexit, label %while.body - - %indvars.iv.i423 = phi i64 [ %indvars.iv.next.i424, %while.body ], [ 0, %while.body.preheader ] - %i.22.i = phi i32 [ %add103.i, %while.body ], [ %rem.i, %while.body.preheader ] - %arrayidx62.i = getelementptr inbounds float, float* %arrayidx200, i64 %indvars.iv.i423 - %t1 = load float, float* %arrayidx62.i, align 4 - %arrayidx64.i = getelementptr inbounds float, float* %arrayidx164, i64 %indvars.iv.i423 - %t2 = load float, float* %arrayidx64.i, align 4 - %mul65.i = fmul fast float %t2, %t22 - %add66.i = fadd fast float %mul65.i, %t1 - store float %add66.i, float* %arrayidx62.i, align 4 - %t3 = add nsw i64 %indvars.iv.i423, 1 - %arrayidx71.i = getelementptr inbounds float, float* %arrayidx200, i64 %t3 - %t4 = load float, float* %arrayidx71.i, align 4 - %arrayidx74.i = getelementptr inbounds float, float* %arrayidx164, i64 %t3 - %t5 = load float, float* %arrayidx74.i, align 4 - %mul75.i = fmul fast float %t5, %t22 - %add76.i = fadd fast float %mul75.i, %t4 - store float %add76.i, float* %arrayidx71.i, align 4 - %add103.i = add nsw i32 %i.22.i, 2 - %t6 = sext i32 %add103.i to i64 - %cmp58.i = icmp slt i64 %t6, %t7 - %indvars.iv.next.i424 = add i64 %indvars.iv.i423, 2 - br i1 %cmp58.i, label %while.body, label %while.end.loopexit - -while.end.loopexit: - br label %while.end - -while.end: - ret void -} - -; Function Attrs: noinline norecurse nounwind -define i32 @test2(i64 %n, i32* nocapture %x, i32* nocapture readonly %y) { -entry: - %cmp18 = icmp sgt i64 %n, 0 - br i1 %cmp18, label %for.body.preheader, label %for.end - -for.body.preheader: ; preds = %entry - br label %for.body - -for.body: ; preds = %for.body.preheader, %for.body - -;CHECK: for.body: -;CHECK-NEXT: %indvar = phi i64 [ %indvar.next, %for.body ], [ 0, %for.body.preheader ] -;CHECK-NEXT: %arrayidx = getelementptr inbounds i32, i32* %y, i64 %indvar -;CHECK-NEXT: [[T1:%[0-9]+]] = load i32, i32* %arrayidx, align 4 -;CHECK-NEXT: %arrayidx3 = getelementptr inbounds i32, i32* %x, i64 %indvar -;CHECK-NEXT: store i32 [[T1]], i32* %arrayidx3, align 4 -;CHECK-NEXT: %indvar.next = add i64 %indvar, 1 -;CHECK-NEXT: %exitcond = icmp eq i64 %indvar, %{{[0-9]+}} -;CHECK-NEXT: br i1 %exitcond, label %for.end.loopexit, label %for.body - - %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ] - %arrayidx = getelementptr inbounds i32, i32* %y, i64 %indvars.iv - %0 = load i32, i32* %arrayidx, align 4 - %arrayidx3 = getelementptr inbounds i32, i32* %x, i64 %indvars.iv - store i32 %0, i32* %arrayidx3, align 4 - %1 = or i64 %indvars.iv, 1 - %arrayidx5 = getelementptr inbounds i32, i32* %y, i64 %1 - %2 = load i32, i32* %arrayidx5, align 4 - %arrayidx8 = getelementptr inbounds i32, i32* %x, i64 %1 - store i32 %2, i32* %arrayidx8, align 4 - %indvars.iv.next = add nuw nsw i64 %indvars.iv, 2 - %cmp = icmp slt i64 %indvars.iv.next, %n - br i1 %cmp, label %for.body, label %for.end.loopexit - -for.end.loopexit: ; preds = %for.body - br label %for.end - -for.end: ; preds = %for.end.loopexit, %entry - ret i32 0 -} - -; Function Attrs: noinline norecurse nounwind -define i32 @test3(i32 %n, i32* nocapture %x, i32* nocapture readonly %y) { -entry: - %cmp21 = icmp sgt i32 %n, 0 - br i1 %cmp21, label %for.body.preheader, label %for.end - -for.body.preheader: ; preds = %entry - br label %for.body - -for.body: ; preds = %for.body.preheader, %for.body - -;CHECK: for.body: -;CHECK: %add12 = add i8 %i.022, 2 -;CHECK-NEXT: %conv = sext i8 %add12 to i32 -;CHECK-NEXT: %cmp = icmp slt i32 %conv, %n -;CHECK-NEXT: br i1 %cmp, label %for.body, label %for.end.loopexit - - %conv23 = phi i32 [ %conv, %for.body ], [ 0, %for.body.preheader ] - %i.022 = phi i8 [ %add12, %for.body ], [ 0, %for.body.preheader ] - %idxprom = sext i8 %i.022 to i64 - %arrayidx = getelementptr inbounds i32, i32* %y, i64 %idxprom - %0 = load i32, i32* %arrayidx, align 4 - %arrayidx3 = getelementptr inbounds i32, i32* %x, i64 %idxprom - store i32 %0, i32* %arrayidx3, align 4 - %add = or i32 %conv23, 1 - %idxprom5 = sext i32 %add to i64 - %arrayidx6 = getelementptr inbounds i32, i32* %y, i64 %idxprom5 - %1 = load i32, i32* %arrayidx6, align 4 - %arrayidx10 = getelementptr inbounds i32, i32* %x, i64 %idxprom5 - store i32 %1, i32* %arrayidx10, align 4 - %add12 = add i8 %i.022, 2 - %conv = sext i8 %add12 to i32 - %cmp = icmp slt i32 %conv, %n - br i1 %cmp, label %for.body, label %for.end.loopexit - -for.end.loopexit: ; preds = %for.body - br label %for.end - -for.end: ; preds = %for.end.loopexit, %entry - ret i32 0 -} - -; Function Attrs: noinline norecurse nounwind -define i32 @test4(i64 %n, i32* nocapture %x, i32* nocapture readonly %y) { -entry: - %cmp18 = icmp eq i64 %n, 0 - br i1 %cmp18, label %for.end, label %for.body.preheader - -for.body.preheader: ; preds = %entry - br label %for.body - -for.body: ; preds = %for.body.preheader, %for.body - -;CHECK: for.body: -;CHECK-NEXT: %indvar = phi i64 [ %indvar.next, %for.body ], [ 0, %for.body.preheader ] -;CHECK-NEXT: %arrayidx = getelementptr inbounds i32, i32* %y, i64 %indvar -;CHECK-NEXT: [[T1:%[0-9]+]] = load i32, i32* %arrayidx, align 4 -;CHECK-NEXT: %arrayidx3 = getelementptr inbounds i32, i32* %x, i64 %indvar -;CHECK-NEXT: store i32 [[T1]], i32* %arrayidx3, align 4 -;CHECK-NEXT: %indvar.next = add i64 %indvar, 1 -;CHECK-NEXT: %exitcond = icmp eq i64 %indvar, %{{[0-9]+}} -;CHECK-NEXT: br i1 %exitcond, label %for.end.loopexit, label %for.body - - %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ] - %arrayidx = getelementptr inbounds i32, i32* %y, i64 %indvars.iv - %0 = load i32, i32* %arrayidx, align 4 - %arrayidx3 = getelementptr inbounds i32, i32* %x, i64 %indvars.iv - store i32 %0, i32* %arrayidx3, align 4 - %1 = or i64 %indvars.iv, 1 - %arrayidx5 = getelementptr inbounds i32, i32* %y, i64 %1 - %2 = load i32, i32* %arrayidx5, align 4 - %arrayidx8 = getelementptr inbounds i32, i32* %x, i64 %1 - store i32 %2, i32* %arrayidx8, align 4 - %indvars.iv.next = add nuw nsw i64 %indvars.iv, 2 - %cmp = icmp ult i64 %indvars.iv.next, %n - br i1 %cmp, label %for.body, label %for.end.loopexit - -for.end.loopexit: ; preds = %for.body - br label %for.end - -for.end: ; preds = %for.end.loopexit, %entry - ret i32 0 -} -