From d363ae52995059906d99f7588f47bf891e7db485 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Thu, 31 Jan 2013 00:01:45 +0000 Subject: Fix ConstantFold's folding of icmp instructions to recognize that, for example, a one-past-the-end pointer from one global variable may be equal to the base pointer of another global variable. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173995 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/Assembler/ConstantExprNoFold.ll | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 test/Assembler/ConstantExprNoFold.ll (limited to 'test/Assembler') diff --git a/test/Assembler/ConstantExprNoFold.ll b/test/Assembler/ConstantExprNoFold.ll new file mode 100644 index 0000000..83e8909 --- /dev/null +++ b/test/Assembler/ConstantExprNoFold.ll @@ -0,0 +1,23 @@ +; This test checks to make sure that constant exprs don't fold in some simple +; situations + +; RUN: llvm-as < %s | llvm-dis | FileCheck %s + +; Even give it a datalayout, to tempt folding as much as possible. +target datalayout = "p:32:32" + +@A = global i64 0 +@B = global i64 0 + +; Don't fold this. @A might really be allocated next to @B, in which case the +; icmp should return true. It's not valid to *dereference* in @B from a pointer +; based on @A, but icmp isn't a dereference. + +; CHECK: @C = global i1 icmp eq (i64* getelementptr inbounds (i64* @A, i64 1), i64* @B) +@C = global i1 icmp eq (i64* getelementptr inbounds (i64* @A, i64 1), i64* @B) + +; Don't fold this completely away either. In theory this could be simplified +; to only use a gep on one side of the icmp though. + +; CHECK: @D = global i1 icmp eq (i64* getelementptr inbounds (i64* @A, i64 1), i64* getelementptr inbounds (i64* @B, i64 2)) +@D = global i1 icmp eq (i64* getelementptr inbounds (i64* @A, i64 1), i64* getelementptr inbounds (i64* @B, i64 2)) -- cgit v1.1