llvm-mirror/test/Transforms/GlobalOpt/2009-01-13-phi-user.ll
Chris Lattner 2461d79aa9 rewrite OptimizeAwayTrappingUsesOfLoads to 1) avoid a temporary
vector and extraneous loop over it, 2) not delete globals used by
phis/selects etc which could actually be useful.  This fixes PR3321.
Many thanks to Duncan for narrowing this down.

llvm-svn: 62201
2009-01-14 00:12:58 +00:00

36 lines
1.3 KiB
LLVM

; RUN: llvm-as < %s | opt -globalopt | llvm-dis | grep {phi.*@head}
; PR3321
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
target triple = "x86_64-unknown-linux-gnu"
%struct.node = type { %struct.node*, i32 }
@head = internal global %struct.node* null ; <%struct.node**> [#uses=2]
@node = internal global %struct.node { %struct.node* null, i32 42 }, align 16 ; <%struct.node*> [#uses=1]
define i32 @f() nounwind {
entry:
store %struct.node* @node, %struct.node** @head, align 8
br label %bb1
bb: ; preds = %bb1
%0 = getelementptr %struct.node* %t.0, i64 0, i32 1 ; <i32*> [#uses=1]
%1 = load i32* %0, align 4 ; <i32> [#uses=1]
%2 = getelementptr %struct.node* %t.0, i64 0, i32 0 ; <%struct.node**> [#uses=1]
br label %bb1
bb1: ; preds = %bb, %entry
%value.0 = phi i32 [ undef, %entry ], [ %1, %bb ] ; <i32> [#uses=1]
%t.0.in = phi %struct.node** [ @head, %entry ], [ %2, %bb ] ; <%struct.node**> [#uses=1]
%t.0 = load %struct.node** %t.0.in ; <%struct.node*> [#uses=3]
%3 = icmp eq %struct.node* %t.0, null ; <i1> [#uses=1]
br i1 %3, label %bb2, label %bb
bb2: ; preds = %bb1
ret i32 %value.0
}
define i32 @main() nounwind {
entry:
%0 = call i32 @f() nounwind ; <i32> [#uses=1]
ret i32 %0
}