Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -670,6 +670,16 @@
 
   unsigned BitWidth = Known.getBitWidth();
 
+  // Refine Known set if the pointer alignment is set by assume bundles (only
+  // minimum alignment is set if the size of the bundle is three).
+  if (Q.CxtI && V->getType()->isPointerTy()) {
+    SmallVector<Attribute::AttrKind, 2> AttrKinds{Attribute::Alignment};
+    if (RetainedKnowledge RK =
+            getKnowledgeValidInContext(V, AttrKinds, Q.CxtI, Q.DT, Q.AC)) {
+      Known.Zero.setLowBits(countTrailingZeros(RK.ArgValue));
+    }
+  }
+
   // Note that the patterns below need to be kept in sync with the code
   // in AssumptionCache::updateAffectedValues.
 
Index: llvm/test/Analysis/BasicAA/featuretest.ll
===================================================================
--- llvm/test/Analysis/BasicAA/featuretest.ll
+++ llvm/test/Analysis/BasicAA/featuretest.ll
@@ -128,7 +128,7 @@
 ; USE_ASSUME-LABEL: @gep_distance_test3(
 ; USE_ASSUME-NEXT:    [[C1:%.*]] = getelementptr i32, i32* [[A:%.*]], i64 1
 ; USE_ASSUME-NEXT:    [[C:%.*]] = bitcast i32* [[C1]] to i8*
-; USE_ASSUME-NEXT:    store i8 42, i8* [[C]], align 1
+; USE_ASSUME-NEXT:    store i8 42, i8* [[C]], align 4
 ; USE_ASSUME-NEXT:    call void @llvm.assume(i1 true) [ "dereferenceable"(i32* [[A]], i64 4), "nonnull"(i32* [[A]]), "align"(i32* [[A]], i64 4) ]
 ; USE_ASSUME-NEXT:    ret i32 0
 ;
Index: llvm/test/Analysis/ValueTracking/assume-queries-counter.ll
===================================================================
--- llvm/test/Analysis/ValueTracking/assume-queries-counter.ll
+++ llvm/test/Analysis/ValueTracking/assume-queries-counter.ll
@@ -2,8 +2,8 @@
 
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -instcombine --debug-counter=assume-queries-counter-skip=0,assume-queries-counter-count=1 -S | FileCheck %s --check-prefixes=SAME,COUNTER1
-; RUN: opt < %s -instcombine --debug-counter=assume-queries-counter-skip=1,assume-queries-counter-count=2 -S | FileCheck %s --check-prefixes=SAME,COUNTER2
-; RUN: opt < %s -instcombine --debug-counter=assume-queries-counter-skip=2,assume-queries-counter-count=1 -S | FileCheck %s --check-prefixes=SAME,COUNTER3
+; RUN: opt < %s -instcombine --debug-counter=assume-queries-counter-skip=1,assume-queries-counter-count=4 -S | FileCheck %s --check-prefixes=SAME,COUNTER2
+; RUN: opt < %s -instcombine --debug-counter=assume-queries-counter-skip=6,assume-queries-counter-count=1 -S | FileCheck %s --check-prefixes=SAME,COUNTER3
 
 declare i1 @get_val()
 declare void @llvm.assume(i1)
Index: llvm/test/Transforms/InstCombine/assume-align.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/InstCombine/assume-align.ll
@@ -0,0 +1,78 @@
+; RUN: opt -S -passes=instcombine,simplify-cfg < %s 2>&1 | FileCheck %s
+
+declare void @llvm.assume(i1 noundef)
+
+define void @f1(i8* %a) {
+; CHECK-LABEL: @f1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[PTR:%.*]] = getelementptr inbounds i8, i8* [[A:%.*]], i64 4
+; CHECK-NEXT:    [[TMP0:%.*]] = ptrtoint i8* [[PTR]] to i64
+; CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[TMP0]], 3
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i64 [[TMP1]], 0
+; CHECK-NEXT:    br i1 [[TMP2]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(i8* [[PTR]], i64 4) ]
+; CHECK-NEXT:    [[TMP3:%.*]] = bitcast i8* [[PTR]] to i32*
+; CHECK-NEXT:    store i32 4, i32* [[TMP3]], align 4
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %ptr = getelementptr inbounds i8, i8* %a, i64 4
+  %0 = ptrtoint i8* %ptr to i64
+  %1 = and i64 %0, 3
+  %2 = icmp eq i64 %1, 0
+  br i1 %2, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  call void @llvm.assume(i1 true) [ "align"(i8* %ptr, i64 4) ]
+  %3 = ptrtoint i8* %ptr to i64
+  %4 = and i64 %3, 3
+  %5 = icmp eq i64 %4, 0
+  br i1 %5, label %if.then1, label %if.else1
+
+if.then1:                                         ; preds = %if.then
+  %6 = bitcast i8* %ptr to i32*
+  store i32 4, i32* %6, align 4
+  br label %if.end
+
+if.else1:                                         ; preds = %if.then
+  store i8 1, i8* %ptr, align 1
+  br label %if.end
+
+if.end:                                           ; preds = %if.then1, %if.else1, %entry
+  ret void
+}
+
+define void @f2(i8* %a) {
+; CHECK-LABEL: @f2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(i8* [[A:%.*]], i64 32, i32 24) ]
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds i8, i8* [[A]], i64 8
+; CHECK-NEXT:    [[TMP1:%.*]] = ptrtoint i8* [[TMP0]] to i64
+; CHECK-NEXT:    [[TMP2:%.*]] = and i64 [[TMP1]], 8
+; CHECK-NEXT:    [[TMP3:%.*]] = icmp eq i64 [[TMP2]], 0
+; CHECK-NEXT:    br i1 [[TMP3]], label [[IF_THEN1:%.*]], label [[IF_ELSE1:%.*]]
+;
+entry:
+  call void @llvm.assume(i1 true) [ "align"(i8* %a, i64 32, i32 24) ]
+  %0 = getelementptr inbounds i8, i8* %a, i64 8
+  %1 = ptrtoint i8* %0 to i64
+  %2 = and i64 %1, 15
+  %3 = icmp eq i64 %2, 0
+  br i1 %3, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+  %4 = bitcast i8* %0 to i64*
+  store i64 16, i64* %4, align 4
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+  store i8 1, i8* %0, align 1
+  br label %if.end
+
+if.end:                                           ; preds = %if.else, %if.then
+  ret void
+}
+