2 files changed, 43 insertions, 1 deletions
diff --git a/test/CodeGen/X86/inline-asm-sp-clobber-memcpy.ll b/test/CodeGen/X86/inline-asm-sp-clobber-memcpy.ll
new file mode 100644
index 0000000000..b55571bcba
--- /dev/null
+++ b/test/CodeGen/X86/inline-asm-sp-clobber-memcpy.ll
@@ -0,0 +1,17 @@
+; RUN: llc < %s -force-align-stack -mtriple i386-apple-darwin -mcpu=i486 | FileCheck %s
+
+%struct.foo = type { [88 x i8] }
+
+declare void @bar(i8* nocapture, %struct.foo* align 4 byval) nounwind
+
+; PR19012
+; Don't clobber %esi if we have inline asm that clobbers %esp.
+define void @test1(%struct.foo* nocapture %x, i32 %y, i8* %z) nounwind {
+  call void @bar(i8* %z, %struct.foo* align 4 byval %x)
+  call void asm sideeffect inteldialect "xor esp, esp", "=*m,~{flags},~{esp},~{esp},~{dirflag},~{fpsr},~{flags}"(i8* %z)
+  ret void
+
+; CHECK-LABEL: test1:
+; CHECK: movl %esp, %esi
+; CHECK-NOT: rep;movsl
+}
diff --git a/test/CodeGen/X86/stack-align-memcpy.ll b/test/CodeGen/X86/stack-align-memcpy.ll
index 87bb85fad8..0cc3aa8488 100644
--- a/test/CodeGen/X86/stack-align-memcpy.ll
+++ b/test/CodeGen/X86/stack-align-memcpy.ll
@@ -2,6 +2,9 @@
 
 %struct.foo = type { [88 x i8] }
 
+declare void @bar(i8* nocapture, %struct.foo* align 4 byval) nounwind
+declare void @baz(i8*) nounwind
+
 ; PR15249
 ; We can't use rep;movsl here because it clobbers the base pointer in %esi.
 define void @test1(%struct.foo* nocapture %x, i32 %y) nounwind {
@@ -15,4 +18,26 @@ define void @test1(%struct.foo* nocapture %x, i32 %y) nounwind {
 ; CHECK-NOT: rep;movsl
 }
 
-declare void @bar(i8* nocapture, %struct.foo* align 4 byval) nounwind
+; PR19012
+; Also don't clobber %esi if the dynamic alloca comes after the memcpy.
+define void @test2(%struct.foo* nocapture %x, i32 %y, i8* %z) nounwind {
+  call void @bar(i8* %z, %struct.foo* align 4 byval %x)
+  %dynalloc = alloca i8, i32 %y, align 1
+  call void @baz(i8* %dynalloc)
+  ret void
+
+; CHECK-LABEL: test2:
+; CHECK: movl %esp, %esi
+; CHECK-NOT: rep;movsl
+}
+
+; Check that we do use rep movs if we make the alloca static.
+define void @test3(%struct.foo* nocapture %x, i32 %y, i8* %z) nounwind {
+  call void @bar(i8* %z, %struct.foo* align 4 byval %x)
+  %statalloc = alloca i8, i32 8, align 1
+  call void @baz(i8* %statalloc)
+  ret void
+
+; CHECK-LABEL: test3:
+; CHECK: rep;movsl
+}