[SimplifyLibCalls] Don't confuse strcpy_chk for stpcpy_chk.

This was introduced in a faulty refactoring (r225640, mea culpa):
the tests weren't testing the return values, so, for both
__strcpy_chk and __stpcpy_chk, we would return the end of the
buffer (matching stpcpy) instead of the beginning (for strcpy).

The root cause was the prefix "__" being ignored when comparing,
which made us always pick LibFunc::stpcpy_chk.
Pass the LibFunc::Func directly to avoid this kind of error.
Also, make the testcases as explicit as possible to prevent this.

The now-useful testcases expose another, entangled, stpcpy problem,
with the further simplification.  This was introduced in a
refactoring (r225640) to match the original behavior.

However, this leads to problems when successive simplifications
generate several similar instructions, none of which are removed
by the custom replaceAllUsesWith.

For instance, InstCombine (the main user) doesn't erase the
instruction in its custom RAUW.  When trying to simplify say
__stpcpy_chk:
- first, an stpcpy is created (fortified simplifier),
- second, a memcpy is created (normal simplifier), but the
  stpcpy call isn't removed.
- third, InstCombine later revisits the instructions,
  and simplifies the first stpcpy to a memcpy.  We now have
  two memcpys.

llvm-svn: 227250

6 files changed, 155 insertions, 121 deletions

diff --git a/llvm/test/Transforms/InstCombine/memcpy_chk-1.ll b/llvm/test/Transforms/InstCombine/memcpy_chk-1.ll
index 008b838201e..ddaaf82a8e2 100644
--- a/llvm/test/Transforms/InstCombine/memcpy_chk-1.ll
+++ b/llvm/test/Transforms/InstCombine/memcpy_chk-1.ll
@@ -15,46 +15,50 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
 
 ; Check cases where dstlen >= len.
 
-define void @test_simplify1() {
+define i8* @test_simplify1() {
 ; CHECK-LABEL: @test_simplify1(
   %dst = bitcast %struct.T1* @t1 to i8*
   %src = bitcast %struct.T2* @t2 to i8*
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64
-  call i8* @__memcpy_chk(i8* %dst, i8* %src, i64 1824, i64 1824)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* bitcast (%struct.T1* @t1 to i8*), i8* bitcast (%struct.T2* @t2 to i8*), i64 1824, i32 4, i1 false)
+; CHECK-NEXT: ret i8* bitcast (%struct.T1* @t1 to i8*)
+  %ret = call i8* @__memcpy_chk(i8* %dst, i8* %src, i64 1824, i64 1824)
+  ret i8* %ret
 }
 
-define void @test_simplify2() {
+define i8* @test_simplify2() {
 ; CHECK-LABEL: @test_simplify2(
   %dst = bitcast %struct.T1* @t1 to i8*
   %src = bitcast %struct.T3* @t3 to i8*
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64
-  call i8* @__memcpy_chk(i8* %dst, i8* %src, i64 1824, i64 2848)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* bitcast (%struct.T1* @t1 to i8*), i8* bitcast (%struct.T3* @t3 to i8*), i64 1824, i32 4, i1 false)
+; CHECK-NEXT: ret i8* bitcast (%struct.T1* @t1 to i8*)
+  %ret = call i8* @__memcpy_chk(i8* %dst, i8* %src, i64 1824, i64 2848)
+  ret i8* %ret
 }
 
 ; Check cases where dstlen < len.
 
-define void @test_no_simplify1() {
+define i8* @test_no_simplify1() {
 ; CHECK-LABEL: @test_no_simplify1(
   %dst = bitcast %struct.T3* @t3 to i8*
   %src = bitcast %struct.T1* @t1 to i8*
 
-; CHECK-NEXT: call i8* @__memcpy_chk
-  call i8* @__memcpy_chk(i8* %dst, i8* %src, i64 2848, i64 1824)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__memcpy_chk(i8* bitcast (%struct.T3* @t3 to i8*), i8* bitcast (%struct.T1* @t1 to i8*), i64 2848, i64 1824)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__memcpy_chk(i8* %dst, i8* %src, i64 2848, i64 1824)
+  ret i8* %ret
 }
 
-define void @test_no_simplify2() {
+define i8* @test_no_simplify2() {
 ; CHECK-LABEL: @test_no_simplify2(
   %dst = bitcast %struct.T1* @t1 to i8*
   %src = bitcast %struct.T2* @t2 to i8*
 
-; CHECK-NEXT: call i8* @__memcpy_chk
-  call i8* @__memcpy_chk(i8* %dst, i8* %src, i64 1024, i64 0)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__memcpy_chk(i8* bitcast (%struct.T1* @t1 to i8*), i8* bitcast (%struct.T2* @t2 to i8*), i64 1024, i64 0)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__memcpy_chk(i8* %dst, i8* %src, i64 1024, i64 0)
+  ret i8* %ret
 }
 
 define i8* @test_simplify_return_indcall(i8* ()* %alloc) {
diff --git a/llvm/test/Transforms/InstCombine/memmove_chk-1.ll b/llvm/test/Transforms/InstCombine/memmove_chk-1.ll
index 6d93bbbf959..e4e1f6eedf3 100644
--- a/llvm/test/Transforms/InstCombine/memmove_chk-1.ll
+++ b/llvm/test/Transforms/InstCombine/memmove_chk-1.ll
@@ -15,46 +15,50 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
 
 ; Check cases where dstlen >= len.
 
-define void @test_simplify1() {
+define i8* @test_simplify1() {
 ; CHECK-LABEL: @test_simplify1(
   %dst = bitcast %struct.T1* @t1 to i8*
   %src = bitcast %struct.T2* @t2 to i8*
 
-; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64
-  call i8* @__memmove_chk(i8* %dst, i8* %src, i64 1824, i64 1824)
-  ret void
+; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* bitcast (%struct.T1* @t1 to i8*), i8* bitcast (%struct.T2* @t2 to i8*), i64 1824, i32 4, i1 false)
+; CHECK-NEXT: ret i8* bitcast (%struct.T1* @t1 to i8*)
+  %ret = call i8* @__memmove_chk(i8* %dst, i8* %src, i64 1824, i64 1824)
+  ret i8* %ret
 }
 
-define void @test_simplify2() {
+define i8* @test_simplify2() {
 ; CHECK-LABEL: @test_simplify2(
   %dst = bitcast %struct.T1* @t1 to i8*
   %src = bitcast %struct.T3* @t3 to i8*
 
-; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64
-  call i8* @__memmove_chk(i8* %dst, i8* %src, i64 1824, i64 2848)
-  ret void
+; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* bitcast (%struct.T1* @t1 to i8*), i8* bitcast (%struct.T3* @t3 to i8*), i64 1824, i32 4, i1 false)
+; CHECK-NEXT: ret i8* bitcast (%struct.T1* @t1 to i8*)
+  %ret = call i8* @__memmove_chk(i8* %dst, i8* %src, i64 1824, i64 2848)
+  ret i8* %ret
 }
 
 ; Check cases where dstlen < len.
 
-define void @test_no_simplify1() {
+define i8* @test_no_simplify1() {
 ; CHECK-LABEL: @test_no_simplify1(
   %dst = bitcast %struct.T3* @t3 to i8*
   %src = bitcast %struct.T1* @t1 to i8*
 
-; CHECK-NEXT: call i8* @__memmove_chk
-  call i8* @__memmove_chk(i8* %dst, i8* %src, i64 2848, i64 1824)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__memmove_chk(i8* bitcast (%struct.T3* @t3 to i8*), i8* bitcast (%struct.T1* @t1 to i8*), i64 2848, i64 1824)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__memmove_chk(i8* %dst, i8* %src, i64 2848, i64 1824)
+  ret i8* %ret
 }
 
-define void @test_no_simplify2() {
+define i8* @test_no_simplify2() {
 ; CHECK-LABEL: @test_no_simplify2(
   %dst = bitcast %struct.T1* @t1 to i8*
   %src = bitcast %struct.T2* @t2 to i8*
 
-; CHECK-NEXT: call i8* @__memmove_chk
-  call i8* @__memmove_chk(i8* %dst, i8* %src, i64 1024, i64 0)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__memmove_chk(i8* bitcast (%struct.T1* @t1 to i8*), i8* bitcast (%struct.T2* @t2 to i8*), i64 1024, i64 0)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__memmove_chk(i8* %dst, i8* %src, i64 1024, i64 0)
+  ret i8* %ret
 }
 
 declare i8* @__memmove_chk(i8*, i8*, i64, i64)
diff --git a/llvm/test/Transforms/InstCombine/memset_chk-1.ll b/llvm/test/Transforms/InstCombine/memset_chk-1.ll
index 47cc7db998e..27f7293a6bc 100644
--- a/llvm/test/Transforms/InstCombine/memset_chk-1.ll
+++ b/llvm/test/Transforms/InstCombine/memset_chk-1.ll
@@ -11,51 +11,56 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
 
 ; Check cases where dstlen >= len.
 
-define void @test_simplify1() {
+define i8* @test_simplify1() {
 ; CHECK-LABEL: @test_simplify1(
   %dst = bitcast %struct.T* @t to i8*
 
-; CHECK-NEXT: call void @llvm.memset.p0i8.i64
-  call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 1824)
-  ret void
+; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* bitcast (%struct.T* @t to i8*), i8 0, i64 1824, i32 4, i1 false)
+; CHECK-NEXT: ret i8* bitcast (%struct.T* @t to i8*)
+  %ret = call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 1824)
+  ret i8* %ret
 }
 
-define void @test_simplify2() {
+define i8* @test_simplify2() {
 ; CHECK-LABEL: @test_simplify2(
   %dst = bitcast %struct.T* @t to i8*
 
-; CHECK-NEXT: call void @llvm.memset.p0i8.i64
-  call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 3648)
-  ret void
+; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* bitcast (%struct.T* @t to i8*), i8 0, i64 1824, i32 4, i1 false)
+; CHECK-NEXT: ret i8* bitcast (%struct.T* @t to i8*)
+  %ret = call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 3648)
+  ret i8* %ret
 }
 
-define void @test_simplify3() {
+define i8* @test_simplify3() {
 ; CHECK-LABEL: @test_simplify3(
   %dst = bitcast %struct.T* @t to i8*
 
-; CHECK-NEXT: call void @llvm.memset.p0i8.i64
-  call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 -1)
-  ret void
+; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* bitcast (%struct.T* @t to i8*), i8 0, i64 1824, i32 4, i1 false)
+; CHECK-NEXT: ret i8* bitcast (%struct.T* @t to i8*)
+  %ret = call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 -1)
+  ret i8* %ret
 }
 
 ; Check cases where dstlen < len.
 
-define void @test_no_simplify1() {
+define i8* @test_no_simplify1() {
 ; CHECK-LABEL: @test_no_simplify1(
   %dst = bitcast %struct.T* @t to i8*
 
-; CHECK-NEXT: call i8* @__memset_chk
-  call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 400)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__memset_chk(i8* bitcast (%struct.T* @t to i8*), i32 0, i64 1824, i64 400)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 400)
+  ret i8* %ret
 }
 
-define void @test_no_simplify2() {
+define i8* @test_no_simplify2() {
 ; CHECK-LABEL: @test_no_simplify2(
   %dst = bitcast %struct.T* @t to i8*
 
-; CHECK-NEXT: call i8* @__memset_chk
-  call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 0)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__memset_chk(i8* bitcast (%struct.T* @t to i8*), i32 0, i64 1824, i64 0)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__memset_chk(i8* %dst, i32 0, i64 1824, i64 0)
+  ret i8* %ret
 }
 
 declare i8* @__memset_chk(i8*, i32, i64, i64)
diff --git a/llvm/test/Transforms/InstCombine/stpcpy_chk-1.ll b/llvm/test/Transforms/InstCombine/stpcpy_chk-1.ll
index 8a02529c61c..393c5d96d10 100644
--- a/llvm/test/Transforms/InstCombine/stpcpy_chk-1.ll
+++ b/llvm/test/Transforms/InstCombine/stpcpy_chk-1.ll
@@ -11,46 +11,50 @@ target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f3
 
 ; Check cases where slen >= strlen (src).
 
-define void @test_simplify1() {
+define i8* @test_simplify1() {
 ; CHECK-LABEL: @test_simplify1(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
-  call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 60)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 1, i1 false)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 11)
+  %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 60)
+  ret i8* %ret
 }
 
-define void @test_simplify2() {
+define i8* @test_simplify2() {
 ; CHECK-LABEL: @test_simplify2(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
-  call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 12)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 1, i1 false)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 11)
+  %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 12)
+  ret i8* %ret
 }
 
-define void @test_simplify3() {
+define i8* @test_simplify3() {
 ; CHECK-LABEL: @test_simplify3(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
-  call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 -1)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 1, i1 false)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 11)
+  %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 -1)
+  ret i8* %ret
 }
 
 ; Check cases where there are no string constants.
 
-define void @test_simplify4() {
+define i8* @test_simplify4() {
 ; CHECK-LABEL: @test_simplify4(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
 
-; CHECK-NEXT: call i8* @stpcpy
-  call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 -1)
-  ret void
+; CHECK-NEXT: %stpcpy = call i8* @stpcpy(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([60 x i8]* @b, i32 0, i32 0))
+; CHECK-NEXT: ret i8* %stpcpy
+  %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 -1)
+  ret i8* %ret
 }
 
 ; Check case where the string length is not constant.
@@ -60,10 +64,11 @@ define i8* @test_simplify5() {
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK: @__memcpy_chk
+; CHECK-NEXT: %len = call i32 @llvm.objectsize.i32.p0i8(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i1 false)
+; CHECK-NEXT: %1 = call i8* @__memcpy_chk(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 %len)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 11)
   %len = call i32 @llvm.objectsize.i32.p0i8(i8* %dst, i1 false)
   %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 %len)
-; CHECK: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 11)
   ret i8* %ret
 }
 
@@ -73,8 +78,9 @@ define i8* @test_simplify6() {
 ; CHECK-LABEL: @test_simplify6(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
 
-; CHECK: [[LEN:%[a-z]+]] = call i32 @strlen
-; CHECK-NEXT: getelementptr inbounds [60 x i8]* @a, i32 0, i32 [[LEN]]
+; CHECK-NEXT: %strlen = call i32 @strlen(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0))
+; CHECK-NEXT: %1 = getelementptr inbounds [60 x i8]* @a, i32 0, i32 %strlen
+; CHECK-NEXT: ret i8* %1
   %len = call i32 @llvm.objectsize.i32.p0i8(i8* %dst, i1 false)
   %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %dst, i32 %len)
   ret i8* %ret
@@ -82,14 +88,15 @@ define i8* @test_simplify6() {
 
 ; Check case where slen < strlen (src).
 
-define void @test_no_simplify1() {
+define i8* @test_no_simplify1() {
 ; CHECK-LABEL: @test_no_simplify1(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
 
-; CHECK-NEXT: call i8* @__stpcpy_chk
-  call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 8)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__stpcpy_chk(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([60 x i8]* @b, i32 0, i32 0), i32 8)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__stpcpy_chk(i8* %dst, i8* %src, i32 8)
+  ret i8* %ret
 }
 
 declare i8* @__stpcpy_chk(i8*, i8*, i32) nounwind
diff --git a/llvm/test/Transforms/InstCombine/strcpy_chk-1.ll b/llvm/test/Transforms/InstCombine/strcpy_chk-1.ll
index 8e7fec76ef5..e3f163fd087 100644
--- a/llvm/test/Transforms/InstCombine/strcpy_chk-1.ll
+++ b/llvm/test/Transforms/InstCombine/strcpy_chk-1.ll
@@ -11,59 +11,65 @@ target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f3
 
 ; Check cases where slen >= strlen (src).
 
-define void @test_simplify1() {
+define i8* @test_simplify1() {
 ; CHECK-LABEL: @test_simplify1(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
-  call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 60)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 1, i1 false)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0)
+  %ret = call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 60)
+  ret i8* %ret
 }
 
-define void @test_simplify2() {
+define i8* @test_simplify2() {
 ; CHECK-LABEL: @test_simplify2(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
-  call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 12)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 1, i1 false)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0)
+  %ret = call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 12)
+  ret i8* %ret
 }
 
-define void @test_simplify3() {
+define i8* @test_simplify3() {
 ; CHECK-LABEL: @test_simplify3(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
-  call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 -1)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 1, i1 false)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0)
+  %ret = call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 -1)
+  ret i8* %ret
 }
 
 ; Check cases where there are no string constants.
 
-define void @test_simplify4() {
+define i8* @test_simplify4() {
 ; CHECK-LABEL: @test_simplify4(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
 
-; CHECK-NEXT: call i8* @strcpy
-  call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 -1)
-  ret void
+; CHECK-NEXT: %strcpy = call i8* @strcpy(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([60 x i8]* @b, i32 0, i32 0))
+; CHECK-NEXT: ret i8* %strcpy
+  %ret = call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 -1)
+  ret i8* %ret
 }
 
 ; Check case where the string length is not constant.
 
-define void @test_simplify5() {
+define i8* @test_simplify5() {
 ; CHECK-LABEL: @test_simplify5(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK: @__memcpy_chk
+; CHECK-NEXT: %len = call i32 @llvm.objectsize.i32.p0i8(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i1 false)
+; CHECK-NEXT: %1 = call i8* @__memcpy_chk(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 %len)
+; CHECK-NEXT: ret i8* %1
   %len = call i32 @llvm.objectsize.i32.p0i8(i8* %dst, i1 false)
-  call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 %len)
-  ret void
+  %ret = call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 %len)
+  ret i8* %ret
 }
 
 ; Check case where the source and destination are the same.
@@ -72,7 +78,9 @@ define i8* @test_simplify6() {
 ; CHECK-LABEL: @test_simplify6(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
 
-; CHECK: getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0)
+; CHECK-NEXT: %len = call i32 @llvm.objectsize.i32.p0i8(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i1 false)
+; CHECK-NEXT: %ret = call i8* @__strcpy_chk(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i32 %len)
+; CHECK-NEXT: ret i8* %ret
   %len = call i32 @llvm.objectsize.i32.p0i8(i8* %dst, i1 false)
   %ret = call i8* @__strcpy_chk(i8* %dst, i8* %dst, i32 %len)
   ret i8* %ret
@@ -80,14 +88,15 @@ define i8* @test_simplify6() {
 
 ; Check case where slen < strlen (src).
 
-define void @test_no_simplify1() {
+define i8* @test_no_simplify1() {
 ; CHECK-LABEL: @test_no_simplify1(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
 
-; CHECK-NEXT: call i8* @__strcpy_chk
-  call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 8)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__strcpy_chk(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([60 x i8]* @b, i32 0, i32 0), i32 8)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__strcpy_chk(i8* %dst, i8* %src, i32 8)
+  ret i8* %ret
 }
 
 declare i8* @__strcpy_chk(i8*, i8*, i32) nounwind
diff --git a/llvm/test/Transforms/InstCombine/strncpy_chk-1.ll b/llvm/test/Transforms/InstCombine/strncpy_chk-1.ll
index 90b4173ced7..9242a8acdbb 100644
--- a/llvm/test/Transforms/InstCombine/strncpy_chk-1.ll
+++ b/llvm/test/Transforms/InstCombine/strncpy_chk-1.ll
@@ -11,56 +11,61 @@ target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f3
 
 ; Check cases where dstlen >= len
 
-define void @test_simplify1() {
+define i8* @test_simplify1() {
 ; CHECK-LABEL: @test_simplify1(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
-  call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 60)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 1, i1 false)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0)
+  %ret = call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 60)
+  ret i8* %ret
 }
 
-define void @test_simplify2() {
+define i8* @test_simplify2() {
 ; CHECK-LABEL: @test_simplify2(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
-  call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 12)
-  ret void
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 12, i32 1, i1 false)
+; CHECK-NEXT: ret i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0)
+  %ret = call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 12)
+  ret i8* %ret
 }
 
-define void @test_simplify3() {
+define i8* @test_simplify3() {
 ; CHECK-LABEL: @test_simplify3(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
 
-; CHECK-NEXT: call i8* @strncpy
-  call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 60)
-  ret void
+; CHECK-NEXT: %strncpy = call i8* @strncpy(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([60 x i8]* @b, i32 0, i32 0), i32 12)
+; CHECK-NEXT: ret i8* %strncpy
+  %ret = call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 60)
+  ret i8* %ret
 }
 
 ; Check cases where dstlen < len
 
-define void @test_no_simplify1() {
+define i8* @test_no_simplify1() {
 ; CHECK-LABEL: @test_no_simplify1(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
 
-; CHECK-NEXT: call i8* @__strncpy_chk
-  call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 4)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__strncpy_chk(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i32 8, i32 4)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 4)
+  ret i8* %ret
 }
 
-define void @test_no_simplify2() {
+define i8* @test_no_simplify2() {
 ; CHECK-LABEL: @test_no_simplify2(
   %dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
   %src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
 
-; CHECK-NEXT: call i8* @__strncpy_chk
-  call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 0)
-  ret void
+; CHECK-NEXT: %ret = call i8* @__strncpy_chk(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i8* getelementptr inbounds ([60 x i8]* @b, i32 0, i32 0), i32 8, i32 0)
+; CHECK-NEXT: ret i8* %ret
+  %ret = call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 0)
+  ret i8* %ret
 }
 
 declare i8* @__strncpy_chk(i8*, i8*, i32, i32)