llvm-6502/test/Analysis/CFLAliasAnalysis/full-store-partial-alias.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

38 lines
1.4 KiB
LLVM

; RUN: opt -S -tbaa -cfl-aa -gvn < %s | FileCheck -check-prefix=CFLAA %s
; RUN: opt -S -tbaa -gvn < %s | FileCheck %s
; Adapted from the BasicAA full-store-partial-alias.ll test.
; CFL AA should notice that the store stores to the entire %u object,
; so the %tmp5 load is PartialAlias with the store and suppress TBAA.
; Without CFL AA, TBAA should say that %tmp5 is NoAlias with the store.
target datalayout = "e-p:64:64:64"
%union.anon = type { double }
@u = global %union.anon { double -2.500000e-01 }, align 8
@endianness_test = global i64 1, align 8
define i32 @signbit(double %x) nounwind {
; CFLAA: ret i32 %tmp5.lobit
; CHECK: ret i32 0
entry:
%u = alloca %union.anon, align 8
%tmp9 = getelementptr inbounds %union.anon* %u, i64 0, i32 0
store double %x, double* %tmp9, align 8, !tbaa !0
%tmp2 = load i32* bitcast (i64* @endianness_test to i32*), align 8, !tbaa !3
%idxprom = sext i32 %tmp2 to i64
%tmp4 = bitcast %union.anon* %u to [2 x i32]*
%arrayidx = getelementptr inbounds [2 x i32]* %tmp4, i64 0, i64 %idxprom
%tmp5 = load i32* %arrayidx, align 4, !tbaa !3
%tmp5.lobit = lshr i32 %tmp5, 31
ret i32 %tmp5.lobit
}
!0 = metadata !{metadata !4, metadata !4, i64 0}
!1 = metadata !{metadata !"omnipotent char", metadata !2}
!2 = metadata !{metadata !"Simple C/C++ TBAA", null}
!3 = metadata !{metadata !5, metadata !5, i64 0}
!4 = metadata !{metadata !"double", metadata !1}
!5 = metadata !{metadata !"int", metadata !1}