diff --git a/llvm/test/Transforms/GlobalOpt/int_sideeffect.ll b/llvm/test/Transforms/GlobalOpt/int_sideeffect.ll
@@ -0,0 +1,16 @@
+; RUN: opt -S < %s -globalopt | FileCheck %s
+
+; Static evaluation across a @llvm.sideeffect.
+
+; CHECK-NOT: store
+
+declare void @llvm.sideeffect()
+
+@llvm.global_ctors = appending global [1 x { i32, void ()* }] [ { i32, void ()* } { i32 65535, void ()* @ctor } ]
+@G = global i32 0
+
+define internal void @ctor() {
+    store i32 1, i32* @G
+    call void @llvm.sideeffect()
+    ret void
+}
diff --git a/llvm/test/Transforms/InstCombine/int_sideeffect.ll b/llvm/test/Transforms/InstCombine/int_sideeffect.ll
@@ -0,0 +1,14 @@
+; RUN: opt -S < %s -instcombine | FileCheck %s
+
+declare void @llvm.sideeffect()
+
+; Store-to-load forwarding across a @llvm.sideeffect.
+
+; CHECK-LABEL: s2l
+; CHECK-NOT: load
+define float @s2l(float* %p) {
+    store float 0.0, float* %p
+    call void @llvm.sideeffect()
+    %t = load float, float* %p
+    ret float %t
+}
diff --git a/llvm/test/Transforms/LICM/int_sideeffect.ll b/llvm/test/Transforms/LICM/int_sideeffect.ll
@@ -0,0 +1,27 @@
+; RUN: opt -S < %s -licm | FileCheck %s
+
+declare void @llvm.sideeffect()
+
+; LICM across a @llvm.sideeffect.
+
+; CHECK-LABEL: licm
+; CHECK: load
+; CHECK: loop:
+; CHECK-NOT: load
+define float @licm(i64 %n, float* nocapture readonly %p) #0 {
+bb0:
+  br label %loop
+
+loop:
+  %i = phi i64 [ 0, %bb0 ], [ %t5, %loop ]
+  %sum = phi float [ 0.000000e+00, %bb0 ], [ %t4, %loop ]
+  call void @llvm.sideeffect()
+  %t3 = load float, float* %p
+  %t4 = fadd float %sum, %t3
+  %t5 = add i64 %i, 1
+  %t6 = icmp ult i64 %t5, %n
+  br i1 %t6, label %loop, label %bb2
+
+bb2:
+  ret float %t4
+}
diff --git a/llvm/test/Transforms/LoadStoreVectorizer/int_sideeffect.ll b/llvm/test/Transforms/LoadStoreVectorizer/int_sideeffect.ll
@@ -0,0 +1,26 @@
+; RUN: opt -S < %s -load-store-vectorizer | FileCheck %s
+
+declare void @llvm.sideeffect()
+
+; load-store vectorization across a @llvm.sideeffect.
+
+; CHECK-LABEL: test
+; CHECK: load <4 x float>
+; CHECK: store <4 x float>
+define void @test(float* %p) {
+    %p0 = getelementptr float, float* %p, i64 0
+    %p1 = getelementptr float, float* %p, i64 1
+    %p2 = getelementptr float, float* %p, i64 2
+    %p3 = getelementptr float, float* %p, i64 3
+    %l0 = load float, float* %p0, align 16
+    %l1 = load float, float* %p1
+    %l2 = load float, float* %p2
+    call void @llvm.sideeffect()
+    %l3 = load float, float* %p3
+    store float %l0, float* %p0, align 16
+    call void @llvm.sideeffect()
+    store float %l1, float* %p1
+    store float %l2, float* %p2
+    store float %l3, float* %p3
+    ret void
+}
diff --git a/llvm/test/Transforms/LoopIdiom/int_sideeffect.ll b/llvm/test/Transforms/LoopIdiom/int_sideeffect.ll
@@ -0,0 +1,23 @@
+; RUN: opt -S < %s -loop-idiom | FileCheck %s
+
+declare void @llvm.sideeffect()
+
+; Loop idiom recognition across a @llvm.sideeffect.
+
+; CHECK-LABEL: zero
+; CHECK: llvm.memset
+define void @zero(float* %p, i64 %n) nounwind {
+bb7.lr.ph:
+  br label %bb7
+
+bb7:
+  %i.02 = phi i64 [ 0, %bb7.lr.ph ], [ %tmp13, %bb7 ]
+  %tmp10 = getelementptr inbounds float, float* %p, i64 %i.02
+  store float 0.000000e+00, float* %tmp10, align 4
+  %tmp13 = add i64 %i.02, 1
+  %tmp6 = icmp ult i64 %tmp13, %n
+  br i1 %tmp6, label %bb7, label %bb14
+
+bb14:
+  ret void
+}
diff --git a/llvm/test/Transforms/LoopVectorize/int_sideeffect.ll b/llvm/test/Transforms/LoopVectorize/int_sideeffect.ll
@@ -0,0 +1,24 @@
+; RUN: opt -S < %s -loop-vectorize -force-vector-width=4 | FileCheck %s
+
+declare void @llvm.sideeffect()
+
+; Vectorization across a @llvm.sideeffect.
+
+; CHECK-LABEL: store_ones
+; CHECK: store <4 x float>
+define void @store_ones(float* %p, i64 %n) nounwind {
+bb7.lr.ph:
+  br label %bb7
+
+bb7:
+  %i.02 = phi i64 [ 0, %bb7.lr.ph ], [ %tmp13, %bb7 ]
+  call void @llvm.sideeffect()
+  %tmp10 = getelementptr inbounds float, float* %p, i64 %i.02
+  store float 1.0, float* %tmp10, align 4
+  %tmp13 = add i64 %i.02, 1
+  %tmp6 = icmp ult i64 %tmp13, %n
+  br i1 %tmp6, label %bb7, label %bb14
+
+bb14:
+  ret void
+}
diff --git a/llvm/test/Transforms/NewGVN/int_sideeffect.ll b/llvm/test/Transforms/NewGVN/int_sideeffect.ll
@@ -0,0 +1,27 @@
+; RUN: opt -S < %s -newgvn | FileCheck %s
+
+declare void @llvm.sideeffect()
+
+; Store-to-load forwarding across a @llvm.sideeffect.
+
+; CHECK-LABEL: s2l
+; CHECK-NOT: load
+define float @s2l(float* %p) {
+    store float 0.0, float* %p
+    call void @llvm.sideeffect()
+    %t = load float, float* %p
+    ret float %t
+}
+
+; Redundant load elimination across a @llvm.sideeffect.
+
+; CHECK-LABEL: rle
+; CHECK: load
+; CHECK-NOT: load
+define float @rle(float* %p) {
+    %r = load float, float* %p
+    call void @llvm.sideeffect()
+    %s = load float, float* %p
+    %t = fadd float %r, %s
+    ret float %t
+}
diff --git a/llvm/test/Transforms/SLPVectorizer/int_sideeffect.ll b/llvm/test/Transforms/SLPVectorizer/int_sideeffect.ll
@@ -0,0 +1,25 @@
+; RUN: opt -S < %s -slp-vectorizer -slp-max-reg-size=128 -slp-min-reg-size=128 | FileCheck %s
+
+declare void @llvm.sideeffect()
+
+; SLP vectorization across a @llvm.sideeffect.
+
+; CHECK-LABEL: test
+; CHECK: store <4 x float>
+define void @test(float* %p) {
+    %p0 = getelementptr float, float* %p, i64 0
+    %p1 = getelementptr float, float* %p, i64 1
+    %p2 = getelementptr float, float* %p, i64 2
+    %p3 = getelementptr float, float* %p, i64 3
+    %l0 = load float, float* %p0
+    %l1 = load float, float* %p1
+    %l2 = load float, float* %p2
+    call void @llvm.sideeffect()
+    %l3 = load float, float* %p3
+    store float %l0, float* %p0
+    call void @llvm.sideeffect()
+    store float %l1, float* %p1
+    store float %l2, float* %p2
+    store float %l3, float* %p3
+    ret void
+}