GC poses hazards to the inliner. Consider:

    define void @f() {
            ...
            call i32 @g()
            ...
    }

    define void @g() {
            ...
    }

The hazards are:

  - @f and @g have GC, but they differ GC. Inlining is invalid. This
    may never occur.
  - @f has no GC, but @g does. g's GC must be propagated to @f.

The other scenarios are safe:

  - @f and @g have the same GC.
  - @f and @g have no GC.
  - @g has no GC.

This patch adds inliner checks for the former two scenarios.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45351 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 47 insertions, 0 deletions

diff --git a/test/CodeGen/Generic/GC/inline.ll b/test/CodeGen/Generic/GC/inline.ll
new file mode 100644
index 0000000000..157e19d2d9
--- /dev/null
+++ b/test/CodeGen/Generic/GC/inline.ll
@@ -0,0 +1,23 @@
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep example
+
+	%IntArray = type { i32, [0 x i32*] }
+
+declare void @llvm.gcroot(i8**, i8*) nounwind 
+
+define i32 @f() {
+	%x = call i32 @g( )		; <i32> [#uses=1]
+	ret i32 %x
+}
+
+define internal i32 @g() gc "example" {
+	%root = alloca i8*		; <i8**> [#uses=2]
+	call void @llvm.gcroot( i8** %root, i8* null )
+	%obj = call %IntArray* @h( )		; <%IntArray*> [#uses=2]
+	%obj.2 = bitcast %IntArray* %obj to i8*		; <i8*> [#uses=1]
+	store i8* %obj.2, i8** %root
+	%Length.ptr = getelementptr %IntArray* %obj, i32 0, i32 0		; <i32*> [#uses=1]
+	%Length = load i32* %Length.ptr		; <i32> [#uses=1]
+	ret i32 %Length
+}
+
+declare %IntArray* @h()
diff --git a/test/CodeGen/Generic/GC/inline2.ll b/test/CodeGen/Generic/GC/inline2.ll
new file mode 100644
index 0000000000..b45ef7c47f
--- /dev/null
+++ b/test/CodeGen/Generic/GC/inline2.ll
@@ -0,0 +1,24 @@
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep sample
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep example
+
+	%IntArray = type { i32, [0 x i32*] }
+
+declare void @llvm.gcroot(i8**, i8*) nounwind 
+
+define i32 @f() gc "sample" {
+	%x = call i32 @g( )		; <i32> [#uses=1]
+	ret i32 %x
+}
+
+define internal i32 @g() gc "example" {
+	%root = alloca i8*		; <i8**> [#uses=2]
+	call void @llvm.gcroot( i8** %root, i8* null )
+	%obj = call %IntArray* @h( )		; <%IntArray*> [#uses=2]
+	%obj.2 = bitcast %IntArray* %obj to i8*		; <i8*> [#uses=1]
+	store i8* %obj.2, i8** %root
+	%Length.ptr = getelementptr %IntArray* %obj, i32 0, i32 0		; <i32*> [#uses=1]
+	%Length = load i32* %Length.ptr		; <i32> [#uses=1]
+	ret i32 %Length
+}
+
+declare %IntArray* @h()