diff --git a/llvm/include/llvm/Analysis/IVUsers.h b/llvm/include/llvm/Analysis/IVUsers.h --- a/llvm/include/llvm/Analysis/IVUsers.h +++ b/llvm/include/llvm/Analysis/IVUsers.h @@ -131,7 +131,8 @@ /// value of the OperandValToReplace of the given IVStrideUse. const SCEV *getReplacementExpr(const IVStrideUse &IU) const; - /// getExpr - Return the expression for the use. + /// getExpr - Return the expression for the use. Returns nullptr if the result + /// is not invertible. const SCEV *getExpr(const IVStrideUse &IU) const; const SCEV *getStride(const IVStrideUse &IU, const Loop *L) const; diff --git a/llvm/lib/Analysis/IVUsers.cpp b/llvm/lib/Analysis/IVUsers.cpp --- a/llvm/lib/Analysis/IVUsers.cpp +++ b/llvm/lib/Analysis/IVUsers.cpp @@ -334,8 +334,15 @@ /// getExpr - Return the expression for the use. const SCEV *IVUsers::getExpr(const IVStrideUse &IU) const { - return normalizeForPostIncUse(getReplacementExpr(IU), IU.getPostIncLoops(), - *SE); + const SCEV *Replacement = getReplacementExpr(IU); + const SCEV *Normalized = + normalizeForPostIncUse(Replacement, IU.getPostIncLoops(), *SE); + const SCEV *Denormalized = + denormalizeForPostIncUse(Normalized, IU.getPostIncLoops(), *SE); + // If the normalized expression isn't invertible. + if (Denormalized != Replacement) + return nullptr; + return Normalized; } static const SCEVAddRecExpr *findAddRecForLoop(const SCEV *S, const Loop *L) { diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp --- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -2707,6 +2707,8 @@ SmallVector Worklist; for (const IVStrideUse &U : IU) { const SCEV *Expr = IU.getExpr(U); + if (!Expr) + continue; // Collect interesting types. Types.insert(SE.getEffectiveSCEVType(Expr->getType())); @@ -3325,6 +3327,8 @@ } const SCEV *S = IU.getExpr(U); + if (!S) + continue; PostIncLoopSet TmpPostIncLoops = U.getPostIncLoops(); // Equality (== and !=) ICmps are special. We can rewrite (i == N) as diff --git a/llvm/test/Transforms/LoopStrengthReduce/X86/pr62660-normalization-failure.ll b/llvm/test/Transforms/LoopStrengthReduce/X86/pr62660-normalization-failure.ll --- a/llvm/test/Transforms/LoopStrengthReduce/X86/pr62660-normalization-failure.ll +++ b/llvm/test/Transforms/LoopStrengthReduce/X86/pr62660-normalization-failure.ll @@ -1,9 +1,6 @@ ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2 ; RUN: opt -loop-reduce -verify-scev -S %s | FileCheck %s -; XFAIL: * -; REQUIRES: asserts - target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-apple-macos" @@ -12,11 +9,16 @@ ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: -; CHECK-NEXT: [[LSR_IV1:%.*]] = phi i32 [ [[LSR_IV_NEXT2:%.*]], [[LOOP]] ], [ 65533, [[ENTRY:%.*]] ] -; CHECK-NEXT: [[LSR_IV:%.*]] = phi i64 [ [[LSR_IV_NEXT:%.*]], [[LOOP]] ], [ -1, [[ENTRY]] ] +; CHECK-NEXT: [[LSR_IV:%.*]] = phi i64 [ [[LSR_IV_NEXT:%.*]], [[LOOP]] ], [ -1, [[ENTRY:%.*]] ] +; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ] +; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[LSR_IV]], 1 +; CHECK-NEXT: [[TMP:%.*]] = trunc i64 [[TMP0]] to i32 +; CHECK-NEXT: [[CONV1:%.*]] = and i32 [[TMP]], 65535 +; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[IV]], -1 +; CHECK-NEXT: [[SUB:%.*]] = add i32 [[ADD]], [[CONV1]] +; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: [[LSR_IV_NEXT]] = add nsw i64 [[LSR_IV]], 1 -; CHECK-NEXT: [[LSR_IV_NEXT2]] = add nuw nsw i32 [[LSR_IV1]], 2 -; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[LSR_IV_NEXT2]], 8 +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[SUB]], 8 ; CHECK-NEXT: br i1 [[CMP]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: exit: ; CHECK-NEXT: ret i64 [[LSR_IV_NEXT]] diff --git a/llvm/test/Transforms/LoopStrengthReduce/scaling-factor-incompat-type.ll b/llvm/test/Transforms/LoopStrengthReduce/scaling-factor-incompat-type.ll --- a/llvm/test/Transforms/LoopStrengthReduce/scaling-factor-incompat-type.ll +++ b/llvm/test/Transforms/LoopStrengthReduce/scaling-factor-incompat-type.ll @@ -17,9 +17,15 @@ ; CHECK: bb4: ; CHECK-NEXT: [[LSR_IV1:%.*]] = phi i16 [ [[LSR_IV_NEXT2:%.*]], [[BB13:%.*]] ], [ 6, [[BB:%.*]] ] ; CHECK-NEXT: [[LSR_IV:%.*]] = phi i64 [ [[LSR_IV_NEXT]], [[BB13]] ], [ 8589934593, [[BB]] ] +; CHECK-NEXT: [[T5:%.*]] = phi i64 [ 2, [[BB]] ], [ [[T14:%.*]], [[BB13]] ] +; CHECK-NEXT: [[T6:%.*]] = add i64 [[T5]], 4 +; CHECK-NEXT: [[T7:%.*]] = trunc i64 [[T6]] to i16 +; CHECK-NEXT: [[T8:%.*]] = urem i16 [[T7]], 3 +; CHECK-NEXT: [[T9:%.*]] = mul i16 [[T8]], 2 ; CHECK-NEXT: [[LSR_IV_NEXT]] = add nuw nsw i64 [[LSR_IV]], 25769803776 ; CHECK-NEXT: [[LSR_IV_NEXT2]] = add nuw nsw i16 [[LSR_IV1]], 6 -; CHECK-NEXT: [[T10:%.*]] = icmp eq i16 1, 0 +; CHECK-NEXT: [[T14]] = add nuw nsw i64 [[T5]], 6 +; CHECK-NEXT: [[T10:%.*]] = icmp eq i16 [[T9]], 1 ; CHECK-NEXT: br i1 [[T10]], label [[BB11:%.*]], label [[BB13]] ; CHECK: bb11: ; CHECK-NEXT: [[T12:%.*]] = udiv i16 1, [[LSR_IV1]]