Index: llvm/include/llvm/Transforms/IPO/Attributor.h
===================================================================
--- llvm/include/llvm/Transforms/IPO/Attributor.h
+++ llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -1953,7 +1953,6 @@
   void unionKnown(const ConstantRange &R) {
     // Don't loose a known range.
     Known = Known.unionWith(R);
-    Assumed = Assumed.unionWith(Known);
   }
 
   /// See IntegerRangeState::unionKnown(..).
Index: llvm/lib/Transforms/IPO/AttributorAttributes.cpp
===================================================================
--- llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -6949,8 +6949,24 @@
       return;
     }
 
-    if (isa<BinaryOperator>(&V) || isa<CmpInst>(&V) || isa<CastInst>(&V))
+    if (isa<CallBase>(&V))
       return;
+
+    if (isa<BinaryOperator>(&V) || isa<CmpInst>(&V))
+      return;
+
+    // Propagate known state for cast instructions.
+    if (CastInst *CI = dyn_cast<CastInst>(&V)) {
+      Value &OpV = *CI->getOperand(0);
+      if (!OpV.getType()->isIntegerTy())
+        return;
+      auto &OpAA =
+          A.getAAFor<AAValueConstantRange>(*this, IRPosition::value(OpV));
+      intersectKnown(
+          OpAA.getKnown().castOp(CI->getOpcode(), getState().getBitWidth()));
+      return;
+    }
+
     // If it is a load instruction with range metadata, use it.
     if (LoadInst *LI = dyn_cast<LoadInst>(&V))
       if (auto *RangeMD = LI->getMetadata(LLVMContext::MD_range)) {
Index: llvm/test/Transforms/Attributor/potential.ll
===================================================================
--- llvm/test/Transforms/Attributor/potential.ll
+++ llvm/test/Transforms/Attributor/potential.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes --check-attributes
 ; RUN: opt -attributor -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=10 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_NPM,NOT_CGSCC_OPM,NOT_TUNIT_NPM,IS__TUNIT____,IS________OPM,IS__TUNIT_OPM
-; RUN: opt -aa-pipeline=basic-aa -passes=attributor -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=8 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_OPM,NOT_CGSCC_NPM,NOT_TUNIT_OPM,IS__TUNIT____,IS________NPM,IS__TUNIT_NPM
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=9 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_OPM,NOT_CGSCC_NPM,NOT_TUNIT_OPM,IS__TUNIT____,IS________NPM,IS__TUNIT_NPM
 ; RUN: opt -attributor-cgscc -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_TUNIT_NPM,NOT_TUNIT_OPM,NOT_CGSCC_NPM,IS__CGSCC____,IS________OPM,IS__CGSCC_OPM
 ; RUN: opt -aa-pipeline=basic-aa -passes=attributor-cgscc -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_TUNIT_NPM,NOT_TUNIT_OPM,NOT_CGSCC_OPM,IS__CGSCC____,IS________NPM,IS__CGSCC_NPM
 ;
@@ -137,13 +137,6 @@
 ; int potential_test3() { return zero_or_one(iszero(0))+zero_or_one(iszero(1)); }
 
 define internal i32 @iszero3(i32 %c) {
-; IS__TUNIT____: Function Attrs: nofree nosync nounwind readnone willreturn
-; IS__TUNIT____-LABEL: define {{[^@]+}}@iszero3
-; IS__TUNIT____-SAME: (i32 [[C:%.*]])
-; IS__TUNIT____-NEXT:    [[CMP:%.*]] = icmp eq i32 [[C]], 0
-; IS__TUNIT____-NEXT:    [[RET:%.*]] = zext i1 [[CMP]] to i32
-; IS__TUNIT____-NEXT:    ret i32 [[RET]]
-;
 ; IS__CGSCC____: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
 ; IS__CGSCC____-LABEL: define {{[^@]+}}@iszero3
 ; IS__CGSCC____-SAME: (i32 [[C:%.*]])
@@ -157,13 +150,6 @@
 }
 
 define internal i32 @less_than_two(i32 %c) {
-; IS__TUNIT____: Function Attrs: nofree nosync nounwind readnone willreturn
-; IS__TUNIT____-LABEL: define {{[^@]+}}@less_than_two
-; IS__TUNIT____-SAME: (i32 [[C:%.*]])
-; IS__TUNIT____-NEXT:    [[CMP:%.*]] = icmp slt i32 [[C]], 2
-; IS__TUNIT____-NEXT:    [[RET:%.*]] = zext i1 [[CMP]] to i32
-; IS__TUNIT____-NEXT:    ret i32 [[RET]]
-;
 ; IS__CGSCC____: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
 ; IS__CGSCC____-LABEL: define {{[^@]+}}@less_than_two
 ; IS__CGSCC____-SAME: (i32 [[C:%.*]])
@@ -177,23 +163,9 @@
 }
 
 define i32 @potential_test3() {
-; IS__TUNIT_OPM: Function Attrs: nofree nosync nounwind readnone willreturn
-; IS__TUNIT_OPM-LABEL: define {{[^@]+}}@potential_test3()
-; IS__TUNIT_OPM-NEXT:    [[CMP1:%.*]] = call i32 @iszero3(i32 0)
-; IS__TUNIT_OPM-NEXT:    [[TRUE1:%.*]] = call i32 @less_than_two(i32 [[CMP1]])
-; IS__TUNIT_OPM-NEXT:    [[CMP2:%.*]] = call i32 @iszero3(i32 1)
-; IS__TUNIT_OPM-NEXT:    [[TRUE2:%.*]] = call i32 @less_than_two(i32 [[CMP2]])
-; IS__TUNIT_OPM-NEXT:    [[RET:%.*]] = add i32 [[TRUE1]], [[TRUE2]]
-; IS__TUNIT_OPM-NEXT:    ret i32 [[RET]]
-;
-; IS__TUNIT_NPM: Function Attrs: nofree nosync nounwind readnone willreturn
-; IS__TUNIT_NPM-LABEL: define {{[^@]+}}@potential_test3()
-; IS__TUNIT_NPM-NEXT:    [[CMP1:%.*]] = call i32 @iszero3(i32 0) [[ATTR0:#.*]], [[RNG0:!range !.*]]
-; IS__TUNIT_NPM-NEXT:    [[TRUE1:%.*]] = call i32 @less_than_two(i32 [[CMP1]]) [[ATTR0]], [[RNG0]]
-; IS__TUNIT_NPM-NEXT:    [[CMP2:%.*]] = call i32 @iszero3(i32 1) [[ATTR0]], [[RNG0]]
-; IS__TUNIT_NPM-NEXT:    [[TRUE2:%.*]] = call i32 @less_than_two(i32 [[CMP2]]) [[ATTR0]], [[RNG0]]
-; IS__TUNIT_NPM-NEXT:    [[RET:%.*]] = add i32 [[TRUE1]], [[TRUE2]]
-; IS__TUNIT_NPM-NEXT:    ret i32 [[RET]]
+; IS__TUNIT____: Function Attrs: nofree nosync nounwind readnone willreturn
+; IS__TUNIT____-LABEL: define {{[^@]+}}@potential_test3()
+; IS__TUNIT____-NEXT:    ret i32 2
 ;
 ; IS__CGSCC____: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
 ; IS__CGSCC____-LABEL: define {{[^@]+}}@potential_test3()
Index: llvm/test/Transforms/Attributor/range.ll
===================================================================
--- llvm/test/Transforms/Attributor/range.ll
+++ llvm/test/Transforms/Attributor/range.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes --check-attributes
-; RUN: opt -attributor -enable-new-pm=0 -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=17 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_NPM,NOT_CGSCC_OPM,NOT_TUNIT_NPM,IS__TUNIT____,IS________OPM,IS__TUNIT_OPM
-; RUN: opt -aa-pipeline=basic-aa -passes=attributor -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=17 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_OPM,NOT_CGSCC_NPM,NOT_TUNIT_OPM,IS__TUNIT____,IS________NPM,IS__TUNIT_NPM
+; RUN: opt -attributor -enable-new-pm=0 -attributor-manifest-internal -attributor-annotate-decl-cs -attributor-max-iterations=17 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_NPM,NOT_CGSCC_OPM,NOT_TUNIT_NPM,IS__TUNIT____,IS________OPM,IS__TUNIT_OPM
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor -attributor-manifest-internal -attributor-annotate-decl-cs -attributor-max-iterations=17 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_OPM,NOT_CGSCC_NPM,NOT_TUNIT_OPM,IS__TUNIT____,IS________NPM,IS__TUNIT_NPM
 ; RUN: opt -attributor-cgscc -enable-new-pm=0 -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_TUNIT_NPM,NOT_TUNIT_OPM,NOT_CGSCC_NPM,IS__CGSCC____,IS________OPM,IS__CGSCC_OPM
 ; RUN: opt -aa-pipeline=basic-aa -passes=attributor-cgscc -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_TUNIT_NPM,NOT_TUNIT_OPM,NOT_CGSCC_OPM,IS__CGSCC____,IS________NPM,IS__CGSCC_NPM
 
Index: llvm/test/Transforms/Attributor/willreturn.ll
===================================================================
--- llvm/test/Transforms/Attributor/willreturn.ll
+++ llvm/test/Transforms/Attributor/willreturn.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes --check-attributes
-; RUN: opt -attributor -enable-new-pm=0 -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=8 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_NPM,NOT_CGSCC_OPM,NOT_TUNIT_NPM,IS__TUNIT____,IS________OPM,IS__TUNIT_OPM
-; RUN: opt -aa-pipeline=basic-aa -passes=attributor -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=8 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_OPM,NOT_CGSCC_NPM,NOT_TUNIT_OPM,IS__TUNIT____,IS________NPM,IS__TUNIT_NPM
+; RUN: opt -attributor -enable-new-pm=0 -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=9 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_NPM,NOT_CGSCC_OPM,NOT_TUNIT_NPM,IS__TUNIT____,IS________OPM,IS__TUNIT_OPM
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=9 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_OPM,NOT_CGSCC_NPM,NOT_TUNIT_OPM,IS__TUNIT____,IS________NPM,IS__TUNIT_NPM
 ; RUN: opt -attributor-cgscc -enable-new-pm=0 -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_TUNIT_NPM,NOT_TUNIT_OPM,NOT_CGSCC_NPM,IS__CGSCC____,IS________OPM,IS__CGSCC_OPM
 ; RUN: opt -aa-pipeline=basic-aa -passes=attributor-cgscc -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_TUNIT_NPM,NOT_TUNIT_OPM,NOT_CGSCC_OPM,IS__CGSCC____,IS________NPM,IS__CGSCC_NPM