Regression test for the Instruction Combining optimizization.

This test helps to see if the optimization correctly handles variables that
are declared constant and external.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7215 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/InstCombine/2003-07-21-ExternalConstant.ll

@@ -0,0 +1,46 @@
+;
+; Test: ExternalConstant
+;
+; Description:
+;	This regression test helps check whether the instruction combining
+;	optimization pass correctly handles global variables which are marked
+;	as external and constant.
+;
+;	If a problem occurs, we should die on an assert().  Otherwise, we
+;	should pass through the optimizer without failure.
+;
+; Extra code:
+; RUN: as < %s | opt -instcombine
+;
+
+target endian = little
+target pointersize = 32
+%silly = external constant int		; <int*> [#uses=1]
+
+implementation   ; Functions:
+
+declare void %bzero(sbyte*, uint)
+
+declare void %bcopy(sbyte*, sbyte*, uint)
+
+declare int %bcmp(sbyte*, sbyte*, uint)
+
+declare int %fputs(sbyte*, sbyte*)
+
+declare int %fputs_unlocked(sbyte*, sbyte*)
+
+int %function(int %a.1) {
+entry:		; No predecessors!
+	%a.0 = alloca int		; <int*> [#uses=2]
+	%result = alloca int		; <int*> [#uses=2]
+	store int %a.1, int* %a.0
+	%tmp.0 = load int* %a.0		; <int> [#uses=1]
+	%tmp.1 = load int* %silly		; <int> [#uses=1]
+	%tmp.2 = add int %tmp.0, %tmp.1		; <int> [#uses=1]
+	store int %tmp.2, int* %result
+	br label %return
+
+return:		; preds = %entry
+	%tmp.3 = load int* %result		; <int> [#uses=1]
+	ret int %tmp.3
+}