llvm-6502/test/Analysis/BasicAA/2006-03-03-BadArraySubscript.ll
Arnold Schwaighofer 3036182e99 BasicAA: Use reachabilty instead of dominance for checking value equality in phi
cycles

This allows the value equality check to work even if we don't have a dominator
tree. Also add some more comments.

I was worried about compile time impacts and did not implement reachability but
used the dominance check in the initial patch. The trade-off was that the
dominator tree was required.
The llvm utility function isPotentiallyReachable cuts off the recursive search
after 32 visits. Testing did not show any compile time regressions showing my
worries unjustfied.

No compile time or performance regressions at O3 -flto -mavx on test-suite +
externals.

Addresses review comments from r198290.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198400 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-03 05:47:03 +00:00

34 lines
1.4 KiB
LLVM

; RUN: opt < %s -basicaa -aa-eval -disable-output 2>&1 | FileCheck %s
; TEST that A[1][0] may alias A[0][i].
target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
; CHECK: 2 no alias responses
define void @test(i32 %N) {
entry:
%X = alloca [3 x [3 x i32]] ; <[3 x [3 x i32]]*> [#uses=4]
%tmp.24 = icmp sgt i32 %N, 0 ; <i1> [#uses=1]
br i1 %tmp.24, label %no_exit, label %loopexit
no_exit: ; preds = %no_exit, %entry
%i.0.0 = phi i32 [ 0, %entry ], [ %inc, %no_exit ] ; <i32> [#uses=2]
%tmp.6 = getelementptr [3 x [3 x i32]]* %X, i32 0, i32 0, i32 %i.0.0 ; <i32*> [#uses=1]
store i32 1, i32* %tmp.6
%tmp.8 = getelementptr [3 x [3 x i32]]* %X, i32 0, i32 0, i32 0 ; <i32*> [#uses=1]
%tmp.9 = load i32* %tmp.8 ; <i32> [#uses=1]
%tmp.11 = getelementptr [3 x [3 x i32]]* %X, i32 0, i32 1, i32 0 ; <i32*> [#uses=1]
%tmp.12 = load i32* %tmp.11 ; <i32> [#uses=1]
%tmp.13 = add i32 %tmp.12, %tmp.9 ; <i32> [#uses=1]
%inc = add i32 %i.0.0, 1 ; <i32> [#uses=2]
%tmp.2 = icmp slt i32 %inc, %N ; <i1> [#uses=1]
br i1 %tmp.2, label %no_exit, label %loopexit
loopexit: ; preds = %no_exit, %entry
%Y.0.1 = phi i32 [ 0, %entry ], [ %tmp.13, %no_exit ] ; <i32> [#uses=1]
%tmp.4 = getelementptr [3 x [3 x i32]]* %X, i32 0, i32 0 ; <[3 x i32]*> [#uses=1]
%tmp.15 = call i32 (...)* @foo( [3 x i32]* %tmp.4, i32 %Y.0.1 ) ; <i32> [#uses=0]
ret void
}
declare i32 @foo(...)