Rename AddReadAttrs to FunctionAttrs, and teach it how

to work out (in a very simplistic way) which function
arguments (pointer arguments only) are only dereferenced
and so do not escape.  Mark such arguments 'nocapture'.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61525 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 102 insertions, 0 deletions

diff --git a/test/Transforms/FunctionAttrs/2008-09-03-Mutual.ll b/test/Transforms/FunctionAttrs/2008-09-03-Mutual.ll
new file mode 100644
index 0000000..5261ac4
--- /dev/null
+++ b/test/Transforms/FunctionAttrs/2008-09-03-Mutual.ll
@@ -0,0 +1,11 @@
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | grep readnone
+
+define i32 @a() {
+	%tmp = call i32 @b( )		; <i32> [#uses=1]
+	ret i32 %tmp
+}
+
+define i32 @b() {
+	%tmp = call i32 @a( )		; <i32> [#uses=1]
+	ret i32 %tmp
+}
diff --git a/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll b/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll
new file mode 100644
index 0000000..a17d381
--- /dev/null
+++ b/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll
@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | grep readnone | count 4
+@x = global i32 0
+
+declare i32 @e() readnone
+
+define i32 @f() {
+	%tmp = call i32 @e( )		; <i32> [#uses=1]
+	ret i32 %tmp
+}
+
+define i32 @g() readonly {
+	ret i32 0
+}
+
+define i32 @h() readnone {
+	%tmp = load i32* @x		; <i32> [#uses=1]
+	ret i32 %tmp
+}
diff --git a/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll b/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
new file mode 100644
index 0000000..cebfdac
--- /dev/null
+++ b/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
@@ -0,0 +1,9 @@
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | grep readonly | count 2
+
+define i32 @f() {
+entry:
+	%tmp = call i32 @e( )		; <i32> [#uses=1]
+	ret i32 %tmp
+}
+
+declare i32 @e() readonly
diff --git a/test/Transforms/FunctionAttrs/2008-09-13-VolatileRead.ll b/test/Transforms/FunctionAttrs/2008-09-13-VolatileRead.ll
new file mode 100644
index 0000000..b6077fd
--- /dev/null
+++ b/test/Transforms/FunctionAttrs/2008-09-13-VolatileRead.ll
@@ -0,0 +1,9 @@
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | not grep read
+; PR2792
+
+@g = global i32 0		; <i32*> [#uses=1]
+
+define i32 @f() {
+	%t = volatile load i32* @g		; <i32> [#uses=1]
+	ret i32 %t
+}
diff --git a/test/Transforms/FunctionAttrs/2008-10-04-LocalMemory.ll b/test/Transforms/FunctionAttrs/2008-10-04-LocalMemory.ll
new file mode 100644
index 0000000..50ca641
--- /dev/null
+++ b/test/Transforms/FunctionAttrs/2008-10-04-LocalMemory.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | grep readnone | count 2
+
+declare i32 @g(i32*) readnone
+
+define i32 @f() {
+	%x = alloca i32		; <i32*> [#uses=2]
+	store i32 0, i32* %x
+	%y = call i32 @g(i32* %x)		; <i32> [#uses=1]
+	ret i32 %y
+}
diff --git a/test/Transforms/FunctionAttrs/2008-12-29-Constant.ll b/test/Transforms/FunctionAttrs/2008-12-29-Constant.ll
new file mode 100644
index 0000000..d9c0117
--- /dev/null
+++ b/test/Transforms/FunctionAttrs/2008-12-29-Constant.ll
@@ -0,0 +1,8 @@
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | grep readnone
+
+@s = external constant i8		; <i8*> [#uses=1]
+
+define i8 @f() {
+	%tmp = load i8* @s		; <i8> [#uses=1]
+	ret i8 %tmp
+}
diff --git a/test/Transforms/FunctionAttrs/2008-12-31-NoCapture.ll b/test/Transforms/FunctionAttrs/2008-12-31-NoCapture.ll
new file mode 100644
index 0000000..6d2ca1e
--- /dev/null
+++ b/test/Transforms/FunctionAttrs/2008-12-31-NoCapture.ll
@@ -0,0 +1,34 @@
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | not grep {@c.*nocapture}
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | grep nocapture | count 3
+@g = global i32* null		; <i32**> [#uses=1]
+
+define i32* @c1(i32* %p) {
+	ret i32* %p
+}
+
+define void @c2(i32* %p) {
+	store i32* %p, i32** @g
+	ret void
+}
+
+define void @c3(i32* %p) {
+	call void @c2(i32* %p)
+	ret void
+}
+
+define i32 @nc1(i32* %p) {
+	%tmp = bitcast i32* %p to i32*		; <i32*> [#uses=2]
+	%val = load i32* %tmp		; <i32> [#uses=1]
+	store i32 0, i32* %tmp
+	ret i32 %val
+}
+
+define void @nc2(i32* %p) {
+	%1 = call i32 @nc1(i32* %p)		; <i32> [#uses=0]
+	ret void
+}
+
+define void @nc3(void ()* %f) {
+	call void %f()
+	ret void
+}
diff --git a/test/Transforms/FunctionAttrs/dg.exp b/test/Transforms/FunctionAttrs/dg.exp
new file mode 100644
index 0000000..f200589
--- /dev/null
+++ b/test/Transforms/FunctionAttrs/dg.exp
@@ -0,0 +1,3 @@
+load_lib llvm.exp
+
+RunLLVMTests [lsort [glob -nocomplain $srcdir/$subdir/*.{ll,c,cpp}]]