diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp --- a/llvm/lib/Transforms/Utils/LoopUtils.cpp +++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp @@ -1395,7 +1395,10 @@ // and next SCEV may errneously get smaller cost. // Collect all the candidate PHINodes to be rewritten. - RewritePhiSet.emplace_back(PN, i, ExitValue, Inst, HighCost); + Instruction *InsertPt = + (isa(Inst) || isa(Inst)) ? + &*Inst->getParent()->getFirstInsertionPt() : Inst; + RewritePhiSet.emplace_back(PN, i, ExitValue, InsertPt, HighCost); } } } diff --git a/llvm/test/Transforms/IndVarSimplify/rewrite-loop-exit-value.ll b/llvm/test/Transforms/IndVarSimplify/rewrite-loop-exit-value.ll --- a/llvm/test/Transforms/IndVarSimplify/rewrite-loop-exit-value.ll +++ b/llvm/test/Transforms/IndVarSimplify/rewrite-loop-exit-value.ll @@ -158,4 +158,42 @@ ret i32 %phi_indvar } +define i16 @pr57336(i16 %end, i16 %m) mustprogress { +; CHECK-LABEL: @pr57336( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_BODY:%.*]] +; CHECK: for.body: +; CHECK-NEXT: [[INC8:%.*]] = phi i16 [ [[INC:%.*]], [[FOR_BODY]] ], [ 0, [[ENTRY:%.*]] ] +; CHECK-NEXT: [[INC]] = add nuw nsw i16 [[INC8]], 1 +; CHECK-NEXT: [[MUL:%.*]] = mul nsw i16 [[INC8]], [[M:%.*]] +; CHECK-NEXT: [[CMP_NOT:%.*]] = icmp sgt i16 [[MUL]], [[END:%.*]] +; CHECK-NEXT: br i1 [[CMP_NOT]], label [[CRIT_EDGE:%.*]], label [[FOR_BODY]] +; CHECK: crit_edge: +; CHECK-NEXT: [[TMP0:%.*]] = call i16 @llvm.smax.i16(i16 [[END]], i16 -1) +; CHECK-NEXT: [[SMAX:%.*]] = add nsw i16 [[TMP0]], 1 +; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i16 [[SMAX]], 0 +; CHECK-NEXT: [[UMIN:%.*]] = zext i1 [[TMP1]] to i16 +; CHECK-NEXT: [[TMP2:%.*]] = sub nsw i16 [[SMAX]], [[UMIN]] +; CHECK-NEXT: [[UMAX:%.*]] = call i16 @llvm.umax.i16(i16 [[M]], i16 1) +; CHECK-NEXT: [[TMP3:%.*]] = udiv i16 [[TMP2]], [[UMAX]] +; CHECK-NEXT: [[TMP4:%.*]] = add i16 [[TMP3]], [[UMIN]] +; CHECK-NEXT: ret i16 [[TMP4]] +; +entry: + br label %for.body + +for.body: + %inc8 = phi i16 [ %inc, %for.body ], [ 0, %entry ] + %inc137 = phi i32 [ %inc1, %for.body ], [ 0, %entry ] + %inc1 = add nsw i32 %inc137, 1 + %inc = add nsw i16 %inc8, 1 + %mul = mul nsw i16 %m, %inc8 + %cmp.not = icmp slt i16 %end, %mul + br i1 %cmp.not, label %crit_edge, label %for.body + +crit_edge: + %inc137.lcssa = phi i32 [ %inc137, %for.body ] + %conv = trunc i32 %inc137.lcssa to i16 + ret i16 %conv +}