Index: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -14,6 +14,7 @@
 #include "llvm/ADT/APSInt.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AssumptionCache.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
@@ -1546,6 +1547,23 @@
   return nullptr;
 }
 
+Instruction *InstCombiner::foldICmpWithDominatingAssume(ICmpInst &ICmp,
+                                                        Value *Op) {
+  for (auto &AssumeVH : AC.assumptionsFor(Op)) {
+    if (!AssumeVH)
+      continue;
+
+    CallInst *Assume = cast<CallInst>(AssumeVH);
+    if (Optional<bool> Imp = isImpliedCondition(Assume->getArgOperand(0), &ICmp,
+                                                DL))
+      if (isValidAssumeForContext(Assume, &ICmp, &DT))
+        return replaceInstUsesWith(ICmp,
+                                   ConstantInt::get(ICmp.getType(), *Imp));
+  }
+
+  return nullptr;
+}
+
 /// Fold icmp (trunc X, Y), C.
 Instruction *InstCombiner::foldICmpTruncConstant(ICmpInst &Cmp,
                                                  TruncInst *Trunc,
@@ -5711,6 +5729,11 @@
     if (Instruction *Res = foldVectorCmp(I, Builder))
       return Res;
 
+  if (Instruction *Res = foldICmpWithDominatingAssume(I, Op0))
+    return Res;
+  if (Instruction *Res = foldICmpWithDominatingAssume(I, Op1))
+    return Res;
+
   return Changed ? &I : nullptr;
 }
 
Index: llvm/lib/Transforms/InstCombine/InstCombineInternal.h
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -931,6 +931,7 @@
 
   Instruction *foldICmpUsingKnownBits(ICmpInst &Cmp);
   Instruction *foldICmpWithDominatingICmp(ICmpInst &Cmp);
+  Instruction *foldICmpWithDominatingAssume(ICmpInst &Cmp, Value *Op);
   Instruction *foldICmpWithConstant(ICmpInst &Cmp);
   Instruction *foldICmpInstWithConstant(ICmpInst &Cmp);
   Instruction *foldICmpInstWithConstantNotInt(ICmpInst &Cmp);
Index: llvm/test/Transforms/InstCombine/assume_icmp.ll
===================================================================
--- llvm/test/Transforms/InstCombine/assume_icmp.ll
+++ llvm/test/Transforms/InstCombine/assume_icmp.ll
@@ -8,22 +8,14 @@
 ; CHECK-LABEL: @basic_ugt(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP1]])
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP2]])
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp uge i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP3]])
-; CHECK-NEXT:    [[CMP4:%.*]] = icmp ult i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP4]])
-; CHECK-NEXT:    [[CMP5:%.*]] = icmp ule i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP5]])
-; CHECK-NEXT:    [[CMP6:%.*]] = icmp ugt i32 [[Y]], [[X]]
-; CHECK-NEXT:    call void @use(i1 [[CMP6]])
-; CHECK-NEXT:    [[CMP7:%.*]] = icmp uge i32 [[Y]], [[X]]
-; CHECK-NEXT:    call void @use(i1 [[CMP7]])
-; CHECK-NEXT:    [[CMP8:%.*]] = icmp ult i32 [[Y]], [[X]]
-; CHECK-NEXT:    call void @use(i1 [[CMP8]])
-; CHECK-NEXT:    [[CMP9:%.*]] = icmp ule i32 [[Y]], [[X]]
-; CHECK-NEXT:    call void @use(i1 [[CMP9]])
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 false)
+; CHECK-NEXT:    call void @use(i1 false)
+; CHECK-NEXT:    call void @use(i1 false)
+; CHECK-NEXT:    call void @use(i1 false)
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ;
   %cmp1 = icmp ugt i32 %x, %y
@@ -56,20 +48,16 @@
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP1]])
 ; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[X]], [[Y]]
 ; CHECK-NEXT:    call void @use(i1 [[CMP2]])
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp uge i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP3]])
-; CHECK-NEXT:    [[CMP4:%.*]] = icmp ult i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP4]])
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 false)
 ; CHECK-NEXT:    [[CMP5:%.*]] = icmp ule i32 [[X]], [[Y]]
 ; CHECK-NEXT:    call void @use(i1 [[CMP5]])
-; CHECK-NEXT:    [[CMP6:%.*]] = icmp ugt i32 [[Y]], [[X]]
-; CHECK-NEXT:    call void @use(i1 [[CMP6]])
+; CHECK-NEXT:    call void @use(i1 false)
 ; CHECK-NEXT:    [[CMP7:%.*]] = icmp uge i32 [[Y]], [[X]]
 ; CHECK-NEXT:    call void @use(i1 [[CMP7]])
 ; CHECK-NEXT:    [[CMP8:%.*]] = icmp ult i32 [[Y]], [[X]]
 ; CHECK-NEXT:    call void @use(i1 [[CMP8]])
-; CHECK-NEXT:    [[CMP9:%.*]] = icmp ule i32 [[Y]], [[X]]
-; CHECK-NEXT:    call void @use(i1 [[CMP9]])
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ;
   %cmp1 = icmp uge i32 %x, %y
@@ -102,14 +90,10 @@
 ; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[Z:%.*]], [[Y]]
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP1]])
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP2]])
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ugt i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP3]])
-; CHECK-NEXT:    [[CMP4:%.*]] = icmp uge i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP4]])
-; CHECK-NEXT:    [[CMP5:%.*]] = icmp ugt i32 [[Z]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP5]])
-; CHECK-NEXT:    [[CMP6:%.*]] = icmp uge i32 [[Z]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[CMP6]])
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ;
   %cmp1 = icmp ugt i32 %x, %y