llvm-6502/test/Analysis/CFLAliasAnalysis/const-expr-gep.ll
Hal Finkel bf301d5670 Add a CFL Alias Analysis implementation
This provides an implementation of CFL alias analysis (including some
supporting data structures). Currently, we don't have any extremely fancy
features, sans some interprocedural analysis (i.e. no field sensitivity, etc.),
and we do best sitting behind BasicAA + TBAA. In such a configuration, we take
~0.6-0.8% of total compile time, and give ~7-8% NoAlias responses to queries
TBAA and BasicAA couldn't answer when bootstrapping LLVM. In testing this on
other projects, we've seen up to 10.5% of queries dropped by BasicAA+TBAA
answered with NoAlias by this algorithm.

Patch by George Burgess IV (with minor modifications by me -- mostly adapting
some BasicAA tests), thanks!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216970 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 21:43:13 +00:00

22 lines
673 B
LLVM

; This testcase consists of alias relations which should be completely
; resolvable by cfl-aa, but require analysis of getelementptr constant exprs.
; Derived from BasicAA/2003-12-11-ConstExprGEP.ll
; RUN: opt < %s -cfl-aa -aa-eval -print-may-aliases -disable-output 2>&1 | FileCheck %s
%T = type { i32, [10 x i8] }
@G = external global %T
; CHECK: Function: test
; CHECK-NOT: May:
define void @test() {
%D = getelementptr %T* @G, i64 0, i32 0
%E = getelementptr %T* @G, i64 0, i32 1, i64 5
%F = getelementptr i32* getelementptr (%T* @G, i64 0, i32 0), i64 0
%X = getelementptr [10 x i8]* getelementptr (%T* @G, i64 0, i32 1), i64 0, i64 5
ret void
}