[CFLAA] Add AttrEscaped, remove bit twiddling functions.

This patch does a few things:

- Unifies AttrAll and AttrUnknown (since they were used for more or less
  the same purpose anyway).

- Introduces AttrEscaped, an attribute that notes that a value escapes
  our analysis for a given set, but not that an unknown value flows into
  said set.

- Removes functions that take bit indices, since we also had functions
  that took bitsets, and the use of both (with similar names) was
  unclear and bug-prone.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21000

llvm-svn: 272040

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/test/Analysis/CFLAliasAnalysis/attr-escape.ll b/llvm/test/Analysis/CFLAliasAnalysis/attr-escape.ll
new file mode 100644
index 00000000000..6e366d5560f
--- /dev/null
+++ b/llvm/test/Analysis/CFLAliasAnalysis/attr-escape.ll
@@ -0,0 +1,18 @@
+; This testcase ensures that CFL AA handles escaped values no more conservative than it should
+
+; RUN: opt < %s -disable-basicaa -cfl-aa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s
+; RUN: opt < %s -aa-pipeline=cfl-aa -passes=aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s
+
+; CHECK: Function: escape_ptrtoint
+; CHECK: NoAlias: i32* %a, i32* %x
+; CHECK: NoAlias: i32* %b, i32* %x
+; CHECK: NoAlias: i32* %a, i32* %b
+; CHECK: MayAlias: i32* %a, i32* %aAlias
+; CHECK: NoAlias: i32* %aAlias, i32* %b
+define void @escape_ptrtoint(i32* %x) {
+	%a = alloca i32, align 4
+	%b = alloca i32, align 4
+	%aint = ptrtoint i32* %a to i64
+	%aAlias = inttoptr i64 %aint to i32*
+	ret void
+}