diff --git a/llvm/test/Analysis/ValueTracking/phi-known-nonzero.ll b/llvm/test/Analysis/ValueTracking/phi-known-nonzero.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Analysis/ValueTracking/phi-known-nonzero.ll
@@ -0,0 +1,280 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=instsimplify < %s -S | FileCheck %s
+
+define i1 @phi_ugt_non_zero(i8 %x) {
+; CHECK-LABEL: @phi_ugt_non_zero(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i8 [[X:%.*]], 32
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[F]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       F:
+; CHECK-NEXT:    br label [[T]]
+;
+entry:
+  %cmp = icmp ugt i8 %x, 32
+  br i1 %cmp, label %T, label %F
+T:
+  %v = phi i8 [ %x, %entry], [-1, %F]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+F:
+  br label %T
+}
+
+define i1 @phi_uge_non_zero(i8 %x) {
+; CHECK-LABEL: @phi_uge_non_zero(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp uge i8 [[X:%.*]], 32
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[F]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       F:
+; CHECK-NEXT:    br label [[T]]
+;
+entry:
+  %cmp = icmp uge i8 %x, 32
+  br i1 %cmp, label %T, label %F
+T:
+  %v = phi i8 [ %x, %entry], [-1, %F]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+F:
+  br label %T
+}
+
+define i1 @phi_ugt_non_zero_fail(i8 %x) {
+; CHECK-LABEL: @phi_ugt_non_zero_fail(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i8 [[X:%.*]], 32
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ 0, [[F]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       F:
+; CHECK-NEXT:    br label [[T]]
+;
+entry:
+  %cmp = icmp ugt i8 %x, 32
+  br i1 %cmp, label %T, label %F
+T:
+  %v = phi i8 [ %x, %entry], [0, %F]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+F:
+  br label %T
+}
+
+define i1 @phi_ult_non_zero(i8 %x) {
+; CHECK-LABEL: @phi_ult_non_zero(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[X:%.*]], 123
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    br label [[F]]
+; CHECK:       F:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[T]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+entry:
+  %cmp = icmp ult i8 %x, 123
+  br i1 %cmp, label %T, label %F
+T:
+  br label %F
+F:
+  %v = phi i8 [ %x, %entry], [-1, %T]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+}
+
+define i1 @phi_ule_non_zero(i8 %x) {
+; CHECK-LABEL: @phi_ule_non_zero(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ule i8 [[X:%.*]], 123
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    br label [[F]]
+; CHECK:       F:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[T]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+entry:
+  %cmp = icmp ule i8 %x, 123
+  br i1 %cmp, label %T, label %F
+T:
+  br label %F
+F:
+  %v = phi i8 [ %x, %entry], [-1, %T]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+}
+
+define i1 @phi_ule_non_zero_fail_wrong_succ(i8 %x) {
+; CHECK-LABEL: @phi_ule_non_zero_fail_wrong_succ(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ule i8 [[X:%.*]], 123
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[F]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       F:
+; CHECK-NEXT:    br label [[T]]
+;
+entry:
+  %cmp = icmp ule i8 %x, 123
+  br i1 %cmp, label %T, label %F
+T:
+  %v = phi i8 [ %x, %entry], [-1, %F]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+F:
+  br label %T
+}
+
+define i1 @phi_ult_non_zero_fail(i8 %x) {
+; CHECK-LABEL: @phi_ult_non_zero_fail(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[X:%.*]], 123
+; CHECK-NEXT:    [[X2:%.*]] = add i8 [[X]], [[X]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    br label [[F]]
+; CHECK:       F:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X2]], [[ENTRY:%.*]] ], [ -1, [[T]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+entry:
+  %cmp = icmp ult i8 %x, 123
+  %x2 = add i8 %x, %x
+  br i1 %cmp, label %T, label %F
+T:
+  br label %F
+F:
+  %v = phi i8 [ %x2, %entry], [-1, %T]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+}
+
+define i1 @phi_ne_non_zero(i8 %x) {
+; CHECK-LABEL: @phi_ne_non_zero(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[X:%.*]], 0
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[F]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       F:
+; CHECK-NEXT:    br label [[T]]
+;
+entry:
+  %cmp = icmp ne i8 %x, 0
+  br i1 %cmp, label %T, label %F
+T:
+  %v = phi i8 [ %x, %entry], [-1, %F]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+F:
+  br label %T
+}
+
+define i1 @phi_eq_non_zero(i8 %x) {
+; CHECK-LABEL: @phi_eq_non_zero(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 44
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[F]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       F:
+; CHECK-NEXT:    br label [[T]]
+;
+entry:
+  %cmp = icmp eq i8 %x, 44
+  br i1 %cmp, label %T, label %F
+T:
+  %v = phi i8 [ %x, %entry], [-1, %F]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+F:
+  br label %T
+}
+
+define i1 @phi_eq_non_zero2(i8 %x) {
+; CHECK-LABEL: @phi_eq_non_zero2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 0
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    br label [[F]]
+; CHECK:       F:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[T]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+entry:
+  %cmp = icmp eq i8 %x, 0
+  br i1 %cmp, label %T, label %F
+T:
+  br label %F
+F:
+  %v = phi i8 [ %x, %entry], [-1, %T]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+}
+
+define i1 @phi_sgt_non_zero(i8 %x) {
+; CHECK-LABEL: @phi_sgt_non_zero(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], 1
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[F]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       F:
+; CHECK-NEXT:    br label [[T]]
+;
+entry:
+  %cmp = icmp sgt i8 %x, 1
+  br i1 %cmp, label %T, label %F
+T:
+  %v = phi i8 [ %x, %entry], [-1, %F]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+F:
+  br label %T
+}
+
+define i1 @phi_sgt_non_zero_fail(i8 %x) {
+; CHECK-LABEL: @phi_sgt_non_zero_fail(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], -1
+; CHECK-NEXT:    br i1 [[CMP]], label [[T:%.*]], label [[F:%.*]]
+; CHECK:       T:
+; CHECK-NEXT:    [[V:%.*]] = phi i8 [ [[X]], [[ENTRY:%.*]] ], [ -1, [[F]] ]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[V]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+; CHECK:       F:
+; CHECK-NEXT:    br label [[T]]
+;
+entry:
+  %cmp = icmp sgt i8 %x, -1
+  br i1 %cmp, label %T, label %F
+T:
+  %v = phi i8 [ %x, %entry], [-1, %F]
+  %r = icmp eq i8 %v, 0
+  ret i1 %r
+F:
+  br label %T
+}