Index: lib/Analysis/ScalarEvolutionExpander.cpp =================================================================== --- lib/Analysis/ScalarEvolutionExpander.cpp +++ lib/Analysis/ScalarEvolutionExpander.cpp @@ -1063,6 +1063,34 @@ return false; } +static bool IsIncrementNSW(ScalarEvolution &SE, const SCEVAddRecExpr *AR) { + if (!isa(AR->getType())) + return false; + + unsigned BitWidth = cast(AR->getType())->getBitWidth(); + Type *WideTy = IntegerType::get(AR->getType()->getContext(), BitWidth * 2); + const SCEV *Step = AR->getStepRecurrence(SE); + const SCEV *OpAfterExtend = SE.getAddExpr(SE.getSignExtendExpr(Step, WideTy), + SE.getSignExtendExpr(AR, WideTy)); + const SCEV *ExtendAfterOp = + SE.getSignExtendExpr(SE.getAddExpr(AR, Step), WideTy); + return ExtendAfterOp == OpAfterExtend; +} + +static bool IsIncrementNUW(ScalarEvolution &SE, const SCEVAddRecExpr *AR) { + if (!isa(AR->getType())) + return false; + + unsigned BitWidth = cast(AR->getType())->getBitWidth(); + Type *WideTy = IntegerType::get(AR->getType()->getContext(), BitWidth * 2); + const SCEV *Step = AR->getStepRecurrence(SE); + const SCEV *OpAfterExtend = SE.getAddExpr(SE.getZeroExtendExpr(Step, WideTy), + SE.getZeroExtendExpr(AR, WideTy)); + const SCEV *ExtendAfterOp = + SE.getZeroExtendExpr(SE.getAddExpr(AR, Step), WideTy); + return ExtendAfterOp == OpAfterExtend; +} + /// getAddRecExprPHILiterally - Helper for expandAddRecExprLiterally. Expand /// the base addrec, which is the addrec without any non-loop-dominating /// values, and return the PHI. @@ -1213,10 +1241,11 @@ IVIncInsertPos : Pred->getTerminator(); Builder.SetInsertPoint(InsertPos); Value *IncV = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract); + if (isa(IncV)) { - if (Normalized->getNoWrapFlags(SCEV::FlagNUW)) + if (IsIncrementNUW(SE, Normalized)) cast(IncV)->setHasNoUnsignedWrap(); - if (Normalized->getNoWrapFlags(SCEV::FlagNSW)) + if (IsIncrementNSW(SE, Normalized)) cast(IncV)->setHasNoSignedWrap(); } PN->addIncoming(IncV, Pred); Index: test/Analysis/ScalarEvolution/scev-expander-incorrect-nowrap.ll =================================================================== --- /dev/null +++ test/Analysis/ScalarEvolution/scev-expander-incorrect-nowrap.ll @@ -0,0 +1,30 @@ +; RUN: opt -indvars -S < %s | FileCheck %s + +declare void @use(i32) +declare void @use.i8(i8) + +define void @f() { +; CHECK-LABEL: @f + entry: + br label %loop + + loop: +; The only use for idx.mirror is to induce an nuw for %idx. It does +; not induce an nuw for %idx.inc + %idx.mirror = phi i8 [ -6, %entry ], [ %idx.mirror.inc, %loop ] + %idx = phi i8 [ -5, %entry ], [ %idx.inc, %loop ] + + %idx.sext = sext i8 %idx to i32 + call void @use(i32 %idx.sext) + + %idx.mirror.inc = add nuw i8 %idx.mirror, 1 + call void @use.i8(i8 %idx.mirror.inc) + + %idx.inc = add i8 %idx, 1 +; CHECK-NOT: %indvars.iv.next = add nuw nsw i32 %indvars.iv, 1 + %cmp = icmp ugt i8 %idx.inc, 0 + br i1 %cmp, label %loop, label %exit + + exit: + ret void +} \ No newline at end of file Index: test/Analysis/ScalarEvolution/zext-signed-addrec.ll =================================================================== --- test/Analysis/ScalarEvolution/zext-signed-addrec.ll +++ test/Analysis/ScalarEvolution/zext-signed-addrec.ll @@ -43,7 +43,7 @@ %shl = and i32 %conv7, 510 store i32 %shl, i32* @c, align 4 -; CHECK: %lsr.iv.next = add i32 %lsr.iv, -258 +; CHECK: %lsr.iv.next = add nsw i32 %lsr.iv, -258 %dec = add i8 %2, -1 %cmp2 = icmp sgt i8 %dec, -1 Index: test/CodeGen/X86/avoid_complex_am.ll =================================================================== --- test/CodeGen/X86/avoid_complex_am.ll +++ test/CodeGen/X86/avoid_complex_am.ll @@ -22,7 +22,7 @@ %arrayidx = getelementptr inbounds double* %b, i64 %tmp %tmp1 = load double* %arrayidx, align 8 ; The induction variable should carry the scaling factor: 1. -; CHECK: [[IVNEXT]] = add nuw i64 [[IV]], 1 +; CHECK: [[IVNEXT]] = add nuw nsw i64 [[IV]], 1 %indvars.iv.next = add i64 %indvars.iv, 1 %arrayidx2 = getelementptr inbounds double* %c, i64 %indvars.iv.next %tmp2 = load double* %arrayidx2, align 8 Index: test/Transforms/IndVarSimplify/overflowcheck.ll =================================================================== --- test/Transforms/IndVarSimplify/overflowcheck.ll +++ test/Transforms/IndVarSimplify/overflowcheck.ll @@ -9,7 +9,7 @@ ; CHECK: @llvm.sadd.with.overflow ; CHECK-LABEL: loop2: ; CHECK-NOT: extractvalue -; CHECK: add nuw nsw +; CHECK: add nuw ; CHECK: @llvm.sadd.with.overflow ; CHECK-LABEL: loop3: ; CHECK-NOT: extractvalue Index: test/Transforms/IndVarSimplify/pr20680.ll =================================================================== --- test/Transforms/IndVarSimplify/pr20680.ll +++ test/Transforms/IndVarSimplify/pr20680.ll @@ -204,8 +204,8 @@ br label %for.inc13 ; CHECK: [[for_inc13]]: -; CHECK-NEXT: %[[indvars_iv_next]] = add nuw nsw i32 %[[indvars_iv]], 1 -; CHECK-NEXT: %[[exitcond4:.*]] = icmp ne i32 %[[indvars_iv]], -1 +; CHECK-NEXT: %[[indvars_iv_next]] = add nsw i32 %[[indvars_iv]], 1 +; CHECK-NEXT: %[[exitcond4:.*]] = icmp ne i32 %[[indvars_iv_next]], 0 ; CHECK-NEXT: br i1 %[[exitcond4]], label %[[for_cond2_preheader]], label %[[for_end15:.*]] for.inc13: ; preds = %for.cond2.for.inc13_crit_edge, %for.cond2.preheader %inc14 = add i8 %storemerge15, 1 Index: test/Transforms/LoopStrengthReduce/count-to-zero.ll =================================================================== --- test/Transforms/LoopStrengthReduce/count-to-zero.ll +++ test/Transforms/LoopStrengthReduce/count-to-zero.ll @@ -19,7 +19,7 @@ %tmp4 = add i32 %c_addr.1, -1 ; [#uses=1] %c_addr.1.be = select i1 %tmp2, i32 %tmp3, i32 %tmp4 ; [#uses=1] %indvar.next = add i32 %indvar, 1 ; [#uses=1] -; CHECK: add i32 %lsr.iv, -1 +; CHECK: add nsw i32 %lsr.iv, -1 br label %bb6 bb6: ; preds = %bb3, %entry Index: test/Transforms/LoopStrengthReduce/uglygep.ll =================================================================== --- test/Transforms/LoopStrengthReduce/uglygep.ll +++ test/Transforms/LoopStrengthReduce/uglygep.ll @@ -59,7 +59,7 @@ ; CHECK: loop0: ; Induction variable is initialized to -2. ; CHECK-NEXT: [[PHIIV:%[^ ]+]] = phi i32 [ [[IVNEXT:%[^ ]+]], %loop0 ], [ -2, %bb ] -; CHECK-NEXT: [[IVNEXT]] = add i32 [[PHIIV]], 1 +; CHECK-NEXT: [[IVNEXT]] = add nuw nsw i32 [[PHIIV]], 1 ; CHECK-NEXT: br i1 false, label %loop0, label %bb0 loop0: ; preds = %loop0, %bb %i0 = phi i32 [ %i0.next, %loop0 ], [ 0, %bb ] ; [#uses=2]