Replace EquivalenceClasses with a custom-built data structure. Many common

operations (like findProperties) should be faster, at the expense of
unionSets being slower in cases that are rare in practise.

Don't erase a dead Instruction. This fixes a memory corruption issue.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30235 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/PredicateSimplifier/2006-08-07-LeaderOffByOne.ll

@@ -0,0 +1,28 @@
+; RUN: llvm-as < %s | opt -predsimplify -disable-output
+
+void %safe_strcpy(uint %size1) {
+entry:
+	%tmp = seteq uint %size1, 0		; <bool> [#uses=1]
+	br bool %tmp, label %return, label %strlen.exit
+
+strlen.exit:		; preds = %entry
+	%tmp = cast ulong 0 to uint		; <uint> [#uses=2]
+	%tmp6 = setlt uint %tmp, %size1		; <bool> [#uses=1]
+	br bool %tmp6, label %cond_true7, label %cond_false19
+
+cond_true7:		; preds = %strlen.exit
+	%tmp9 = seteq uint %tmp, 0		; <bool> [#uses=1]
+	br bool %tmp9, label %cond_next15, label %cond_true10
+
+cond_true10:		; preds = %cond_true7
+	ret void
+
+cond_next15:		; preds = %cond_true7
+	ret void
+
+cond_false19:		; preds = %strlen.exit
+	ret void
+
+return:		; preds = %entry
+	ret void
+}