Index: llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
===================================================================
--- llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
+++ llvm/lib/Transforms/Utils/SimplifyIndVar.cpp
@@ -1898,6 +1898,10 @@
     // to the new (widened) increment.
     auto *OrigInc =
       cast<Instruction>(OrigPhi->getIncomingValueForBlock(LatchBlock));
+    if (isa<OverflowingBinaryOperator>(OrigInc) && OrigInc->hasNoSignedWrap())
+      WideInc->setHasNoSignedWrap(true);
+    if (isa<OverflowingBinaryOperator>(OrigInc) && OrigInc->hasNoUnsignedWrap())
+      WideInc->setHasNoUnsignedWrap(true);
     WideInc->setDebugLoc(OrigInc->getDebugLoc());
   }
 
Index: llvm/test/Transforms/IndVarSimplify/AArch64/widen-loop-comp.ll
===================================================================
--- llvm/test/Transforms/IndVarSimplify/AArch64/widen-loop-comp.ll
+++ llvm/test/Transforms/IndVarSimplify/AArch64/widen-loop-comp.ll
@@ -275,7 +275,7 @@
 ; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i32, i32* [[A:%.*]], i64 [[INDVARS_IV]]
 ; CHECK-NEXT:    [[TMP1:%.*]] = load i32, i32* [[ARRAYIDX]], align 4
 ; CHECK-NEXT:    [[ADD]] = add nsw i32 [[SUM_0]], [[TMP1]]
-; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw i64 [[INDVARS_IV]], 1
+; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1
 ; CHECK-NEXT:    br label [[FOR_COND]]
 ; CHECK:       for.end:
 ; CHECK-NEXT:    [[SUM_0_LCSSA:%.*]] = phi i32 [ [[SUM_0]], [[FOR_COND]] ]
@@ -410,7 +410,7 @@
 ; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i32, i32* [[A:%.*]], i64 [[INDVARS_IV]]
 ; CHECK-NEXT:    [[TMP2:%.*]] = load i32, i32* [[ARRAYIDX]], align 4
 ; CHECK-NEXT:    [[ADD]] = add nsw i32 [[SUM_0]], [[TMP2]]
-; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add i64 [[INDVARS_IV]], 1
+; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nsw i64 [[INDVARS_IV]], 1
 ; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i64 0, [[INDVARS_IV_NEXT]]
 ; CHECK-NEXT:    br i1 [[CMP2]], label [[FOR_COND]], label [[FOR_END]]
 ; CHECK:       for.end:
Index: llvm/test/Transforms/IndVarSimplify/X86/pr27133.ll
===================================================================
--- llvm/test/Transforms/IndVarSimplify/X86/pr27133.ll
+++ llvm/test/Transforms/IndVarSimplify/X86/pr27133.ll
@@ -21,7 +21,7 @@
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret i32 [[C_0_LCSSA]]
 ; CHECK:       for.inc:
-; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw i64 [[INDVARS_IV]], 1
+; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1
 ; CHECK-NEXT:    br label [[FOR_COND]]
 ;
 entry:
Index: llvm/test/Transforms/IndVarSimplify/keep-nsw-nuw-flag.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/IndVarSimplify/keep-nsw-nuw-flag.ll
@@ -0,0 +1,59 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -indvars -S < %s | FileCheck %s
+
+target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+target triple = "aarch64-unknown-linux-gnu"
+
+@a = external global [8000 x float], align 64
+@b = external global [8000 x float], align 64
+@c = external global [8000 x float], align 64
+
+define float @foo(i32 %arg1, i32 %arg2) {
+; CHECK-LABEL: @foo(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = sext i32 [[ARG1:%.*]] to i64
+; CHECK-NEXT:    [[TMP1:%.*]] = sext i32 [[ARG2:%.*]] to i64
+; CHECK-NEXT:    br label [[PREHEADER:%.*]]
+; CHECK:       preheader:
+; CHECK-NEXT:    br label [[BODY:%.*]]
+; CHECK:       body:
+; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[BODY]] ], [ [[TMP0]], [[PREHEADER]] ]
+; CHECK-NEXT:    [[ARRAYIDX_A:%.*]] = getelementptr inbounds [8000 x float], [8000 x float]* @a, i64 0, i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[TMP2:%.*]] = load float, float* [[ARRAYIDX_A]], align 4
+; CHECK-NEXT:    [[ARRAYIDX_B:%.*]] = getelementptr inbounds [8000 x float], [8000 x float]* @b, i64 0, i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[TMP3:%.*]] = load float, float* [[ARRAYIDX_B]], align 4
+; CHECK-NEXT:    [[ARRAYIDX_C:%.*]] = getelementptr inbounds [8000 x float], [8000 x float]* @c, i64 0, i64 [[INDVARS_IV]]
+; CHECK-NEXT:    [[FADD:%.*]] = fadd fast float [[TMP2]], [[TMP3]]
+; CHECK-NEXT:    store float [[FADD]], float* [[ARRAYIDX_C]], align 4
+; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nsw i64 [[INDVARS_IV]], [[TMP1]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i64 [[INDVARS_IV_NEXT]], 8000
+; CHECK-NEXT:    br i1 [[CMP]], label [[BODY]], label [[CLEANUP:%.*]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK:       cleanup:
+; CHECK-NEXT:    br label [[PREHEADER]]
+;
+entry:
+  br label %preheader
+
+preheader:                         ; preds = %cleanup, %entry
+  br label %body
+
+body:                              ; preds = %body, %preheader
+  %iv = phi i32 [ %arg1, %preheader ], [ %add, %body ]
+  %sext = sext i32 %iv to i64
+  %arrayidx.a = getelementptr inbounds [8000 x float], [8000 x float]* @a, i64 0, i64 %sext
+  %0 = load float, float* %arrayidx.a, align 4
+  %arrayidx.b = getelementptr inbounds [8000 x float], [8000 x float]* @b, i64 0, i64 %sext
+  %1 = load float, float* %arrayidx.b, align 4
+  %arrayidx.c = getelementptr inbounds [8000 x float], [8000 x float]* @c, i64 0, i64 %sext
+  %fadd = fadd fast float %0, %1
+  store float %fadd, float* %arrayidx.c, align 4
+  %add = add nsw i32 %iv, %arg2
+  %cmp = icmp slt i32 %add, 8000
+  br i1 %cmp, label %body, label %cleanup, !llvm.loop !0
+
+cleanup:                          ; preds = %body
+  br label %preheader
+}
+
+!0 = distinct !{!0, !1}
+!1 = !{!"llvm.loop.mustprogress"}
Index: llvm/test/Transforms/IndVarSimplify/widen-i32-i8ptr.ll
===================================================================
--- llvm/test/Transforms/IndVarSimplify/widen-i32-i8ptr.ll
+++ llvm/test/Transforms/IndVarSimplify/widen-i32-i8ptr.ll
@@ -16,7 +16,7 @@
 ; CHECK-NEXT:    [[INCDEC_PTR]] = getelementptr inbounds i8, i8* [[GID_0]], i64 1
 ; CHECK-NEXT:    [[ARRAYIDX2115:%.*]] = getelementptr inbounds [15 x i8*], [15 x i8*]* [[PTRIDS]], i64 0, i64 [[INDVARS_IV]]
 ; CHECK-NEXT:    store i8* [[GID_0]], i8** [[ARRAYIDX2115]], align 8
-; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw i64 [[INDVARS_IV]], 1
+; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1
 ; CHECK-NEXT:    br label [[FOR_COND2106]]
 ;
 entry:
Index: llvm/test/Transforms/LoopFlatten/widen-iv.ll
===================================================================
--- llvm/test/Transforms/LoopFlatten/widen-iv.ll
+++ llvm/test/Transforms/LoopFlatten/widen-iv.ll
@@ -41,11 +41,11 @@
 ; CHECK-NEXT:    [[IDXPROM_US:%.*]] = sext i32 [[FLATTEN_TRUNCIV]] to i64
 ; CHECK-NEXT:    [[ARRAYIDX_US:%.*]] = getelementptr inbounds i32, i32* [[A:%.*]], i64 [[IDXPROM_US]]
 ; CHECK-NEXT:    tail call void @f(i32* [[ARRAYIDX_US]])
-; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add i64 [[INDVAR]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add nuw nsw i64 [[INDVAR]], 1
 ; CHECK-NEXT:    [[CMP2_US:%.*]] = icmp slt i64 [[INDVAR_NEXT]], [[TMP0]]
 ; CHECK-NEXT:    br label [[FOR_COND1_FOR_COND_CLEANUP3_CRIT_EDGE_US]]
 ; CHECK:       for.cond1.for.cond.cleanup3_crit_edge.us:
-; CHECK-NEXT:    [[INDVAR_NEXT2]] = add i64 [[INDVAR1]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT2]] = add nuw nsw i64 [[INDVAR1]], 1
 ; CHECK-NEXT:    [[CMP_US:%.*]] = icmp slt i64 [[INDVAR_NEXT2]], [[FLATTEN_TRIPCOUNT]]
 ; CHECK-NEXT:    br i1 [[CMP_US]], label [[FOR_COND1_PREHEADER_US]], label [[FOR_COND_CLEANUP_LOOPEXIT:%.*]]
 ; CHECK:       for.cond.cleanup.loopexit:
@@ -132,12 +132,12 @@
 ; CHECK-NEXT:    [[ARRAYIDX_US:%.*]] = getelementptr inbounds i32, i32* [[A:%.*]], i64 [[INDVAR2]]
 ; CHECK-NEXT:    [[TMP8:%.*]] = load i32, i32* [[ARRAYIDX_US]], align 4
 ; CHECK-NEXT:    tail call void @g(i32 [[TMP8]])
-; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add i64 [[INDVAR]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add nuw nsw i64 [[INDVAR]], 1
 ; CHECK-NEXT:    [[INC_US:%.*]] = add nuw nsw i32 [[J_016_US]], 1
 ; CHECK-NEXT:    [[CMP2_US:%.*]] = icmp slt i64 [[INDVAR_NEXT]], [[TMP0]]
 ; CHECK-NEXT:    br label [[FOR_COND1_FOR_COND_CLEANUP3_CRIT_EDGE_US]]
 ; CHECK:       for.cond1.for.cond.cleanup3_crit_edge.us:
-; CHECK-NEXT:    [[INDVAR_NEXT3]] = add i64 [[INDVAR2]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT3]] = add nuw nsw i64 [[INDVAR2]], 1
 ; CHECK-NEXT:    [[INC6_US]] = add nuw nsw i32 [[I_018_US]], 1
 ; CHECK-NEXT:    [[CMP_US:%.*]] = icmp slt i64 [[INDVAR_NEXT3]], [[FLATTEN_TRIPCOUNT]]
 ; CHECK-NEXT:    br i1 [[CMP_US]], label [[FOR_COND1_PREHEADER_US]], label [[FOR_COND_CLEANUP_LOOPEXIT:%.*]]
@@ -240,7 +240,7 @@
 ; CHECK-NEXT:    [[ARRAYIDX_US:%.*]] = getelementptr inbounds i32, i32* [[A:%.*]], i64 [[IDXPROM_US]]
 ; CHECK-NEXT:    [[TMP4:%.*]] = load i32, i32* [[ARRAYIDX_US]], align 4
 ; CHECK-NEXT:    tail call void @g(i32 [[TMP4]])
-; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add i64 [[INDVAR]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add nuw i64 [[INDVAR]], 1
 ; CHECK-NEXT:    [[CMP2_US:%.*]] = icmp ult i64 [[INDVAR_NEXT]], [[TMP0]]
 ; CHECK-NEXT:    br label [[FOR_COND1_FOR_COND_CLEANUP3_CRIT_EDGE_US]]
 ; CHECK:       for.cond1.for.cond.cleanup3_crit_edge.us:
@@ -335,7 +335,7 @@
 ; CHECK-NEXT:    [[TMP4:%.*]] = load i16, i16* [[ARRAYIDX_US]], align 2
 ; CHECK-NEXT:    [[ADD5_US:%.*]] = add i16 [[TMP4]], [[VAL:%.*]]
 ; CHECK-NEXT:    store i16 [[ADD5_US]], i16* [[ARRAYIDX_US]], align 2
-; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add i64 [[INDVAR]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add nuw i64 [[INDVAR]], 1
 ; CHECK-NEXT:    [[CMP2_US:%.*]] = icmp ult i64 [[INDVAR_NEXT]], [[TMP0]]
 ; CHECK-NEXT:    br label [[FOR_COND1_FOR_INC7_CRIT_EDGE_US]]
 ; CHECK:       for.cond1.for.inc7_crit_edge.us:
@@ -420,7 +420,7 @@
 ; CHECK-NEXT:    [[ADD_US:%.*]] = add i8 [[TMP3]], [[MUL_US]]
 ; CHECK-NEXT:    [[CONV14_US:%.*]] = zext i8 [[FLATTEN_TRUNCIV]] to i32
 ; CHECK-NEXT:    [[CALL_US:%.*]] = tail call i32 @use_32(i32 [[CONV14_US]])
-; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add i64 [[INDVAR]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add nuw i64 [[INDVAR]], 1
 ; CHECK-NEXT:    [[CMP6_US:%.*]] = icmp ult i64 [[INDVAR_NEXT]], [[TMP0]]
 ; CHECK-NEXT:    br label [[FOR_COND3_FOR_COND_CLEANUP8_CRIT_EDGE_US]]
 ; CHECK:       for.cond3.for.cond.cleanup8_crit_edge.us:
@@ -529,7 +529,7 @@
 ; CHECK-NEXT:    [[CALL20_US:%.*]] = tail call i32 @use_16(i16 [[CONV15_US]])
 ; CHECK-NEXT:    [[CONV21_US:%.*]] = zext i8 [[FLATTEN_TRUNCIV]] to i64
 ; CHECK-NEXT:    [[CALL22_US:%.*]] = tail call i32 @use_64(i64 [[CONV21_US]])
-; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add i64 [[INDVAR]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add nuw i64 [[INDVAR]], 1
 ; CHECK-NEXT:    [[CMP6_US:%.*]] = icmp ult i64 [[INDVAR_NEXT]], [[TMP0]]
 ; CHECK-NEXT:    br label [[FOR_COND3_FOR_COND_CLEANUP8_CRIT_EDGE_US]]
 ; CHECK:       for.cond3.for.cond.cleanup8_crit_edge.us:
@@ -643,7 +643,7 @@
 ; CHECK-NEXT:    [[CALL18_US:%.*]] = tail call i32 @use_16(i16 [[FLATTEN_TRUNCIV]])
 ; CHECK-NEXT:    [[CONV19_US:%.*]] = sext i16 [[FLATTEN_TRUNCIV]] to i64
 ; CHECK-NEXT:    [[CALL20_US:%.*]] = tail call i32 @use_64(i64 [[CONV19_US]])
-; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add i64 [[INDVAR]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT:%.*]] = add nuw nsw i64 [[INDVAR]], 1
 ; CHECK-NEXT:    [[CMP6_US:%.*]] = icmp slt i64 [[INDVAR_NEXT]], [[TMP0]]
 ; CHECK-NEXT:    br label [[FOR_COND3_FOR_COND_CLEANUP8_CRIT_EDGE_US]]
 ; CHECK:       for.cond3.for.cond.cleanup8_crit_edge.us:
Index: llvm/test/Transforms/LoopFlatten/widen-iv2.ll
===================================================================
--- llvm/test/Transforms/LoopFlatten/widen-iv2.ll
+++ llvm/test/Transforms/LoopFlatten/widen-iv2.ll
@@ -45,12 +45,12 @@
 ; CHECK-NEXT:    [[IDXPROM_US:%.*]] = sext i32 [[ADD_US]] to i64
 ; CHECK-NEXT:    [[ARRAYIDX_US:%.*]] = getelementptr inbounds i32, i32* [[TMP4]], i64 [[TMP7]]
 ; CHECK-NEXT:    store i32 32, i32* [[ARRAYIDX_US]], align 4
-; CHECK-NEXT:    [[INDVAR_NEXT]] = add i64 [[INDVAR]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT]] = add nuw nsw i64 [[INDVAR]], 1
 ; CHECK-NEXT:    [[INC_US]] = add nuw nsw i32 [[J_014_US]], 1
 ; CHECK-NEXT:    [[CMP2_US:%.*]] = icmp slt i64 [[INDVAR_NEXT]], [[TMP1]]
 ; CHECK-NEXT:    br i1 [[CMP2_US]], label [[FOR_BODY3_US]], label [[FOR_COND1_FOR_INC4_CRIT_EDGE_US]]
 ; CHECK:       for.cond1.for.inc4_crit_edge.us:
-; CHECK-NEXT:    [[INDVAR_NEXT3]] = add i64 [[INDVAR2]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT3]] = add nuw nsw i64 [[INDVAR2]], 1
 ; CHECK-NEXT:    [[INC5_US]] = add nuw nsw i32 [[I_016_US]], 1
 ; CHECK-NEXT:    [[CMP_US:%.*]] = icmp slt i64 [[INDVAR_NEXT3]], [[TMP3]]
 ; CHECK-NEXT:    br i1 [[CMP_US]], label [[FOR_COND1_PREHEADER_US]], label [[FOR_END6_LOOPEXIT:%.*]]
Index: llvm/test/Transforms/LoopFlatten/widen-iv3.ll
===================================================================
--- llvm/test/Transforms/LoopFlatten/widen-iv3.ll
+++ llvm/test/Transforms/LoopFlatten/widen-iv3.ll
@@ -1,5 +1,5 @@
-
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+
 ; RUN: opt < %s -S -loop-flatten \
 ; RUN:     -verify-loop-info -verify-dom-info -verify-scev -verify | \
 ; RUN:     FileCheck %s --check-prefix=CHECK
@@ -25,13 +25,13 @@
 ; CHECK-NEXT:    ret i16 [[ADD5_LCSSA_LCSSA]]
 ; CHECK:       for.cond.cleanup3:
 ; CHECK-NEXT:    [[ADD5_LCSSA]] = phi i16 [ [[ADD5:%.*]], [[FOR_BODY4]] ]
-; CHECK-NEXT:    [[INDVAR_NEXT3]] = add i32 [[INDVAR2]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT3]] = add nuw nsw i32 [[INDVAR2]], 1
 ; CHECK-NEXT:    [[INC7]] = add nuw nsw i16 [[I_013]], 1
 ; CHECK-NEXT:    [[EXITCOND14_NOT:%.*]] = icmp eq i32 [[INDVAR_NEXT3]], 4
 ; CHECK-NEXT:    br i1 [[EXITCOND14_NOT]], label [[FOR_COND_CLEANUP:%.*]], label [[FOR_COND1_PREHEADER]]
 ; CHECK:       for.body4:
 ; CHECK-NEXT:    [[INDVAR:%.*]] = phi i32 [ [[INDVAR_NEXT:%.*]], [[FOR_BODY4]] ], [ 0, [[FOR_COND1_PREHEADER]] ]
-; CHECK-NEXT:    [[J_011:%.*]] = phi i16 [ 0, [[FOR_COND1_PREHEADER]] ]
+; CHECK-NEXT:    [[J_011:%.*]] = phi i16 [ 0, [[FOR_COND1_PREHEADER]] ], [ [[INC:%.*]], [[FOR_BODY4]] ]
 ; CHECK-NEXT:    [[SUM_110:%.*]] = phi i16 [ [[SUM_012]], [[FOR_COND1_PREHEADER]] ], [ [[ADD5]], [[FOR_BODY4]] ]
 ; CHECK-NEXT:    [[TMP2:%.*]] = add nuw nsw i32 [[INDVAR]], [[TMP0]]
 ; CHECK-NEXT:    [[ADD:%.*]] = add nuw nsw i16 [[J_011]], [[MUL]]
@@ -39,8 +39,8 @@
 ; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds [64 x i16], [64 x i16]* @v, i16 0, i16 [[TMP3]]
 ; CHECK-NEXT:    [[TMP4:%.*]] = load i16, i16* [[ARRAYIDX]], align 1
 ; CHECK-NEXT:    [[ADD5]] = add nsw i16 [[TMP4]], [[SUM_110]]
-; CHECK-NEXT:    [[INDVAR_NEXT]] = add i32 [[INDVAR]], 1
-; CHECK-NEXT:    [[INC:%.*]] = add nuw nsw i16 [[J_011]], 1
+; CHECK-NEXT:    [[INDVAR_NEXT]] = add nuw nsw i32 [[INDVAR]], 1
+; CHECK-NEXT:    [[INC]] = add nuw nsw i16 [[J_011]], 1
 ; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i32 [[INDVAR_NEXT]], 16
 ; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP3]], label [[FOR_BODY4]]
 ;