From 44365353a415d37daae9df53fbf6a91677ed90d3 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Mon, 31 Dec 2012 19:51:10 +0000
Subject: [PATCH] Revert "add support for PHI nodes to ObjectSizeOffsetVisitor"

This reverts r171298. Breaks clang selfhost.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171318 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/MemoryBuiltins.cpp        | 17 ++------
 test/Transforms/InstCombine/objsize.ll | 54 --------------------------
 2 files changed, 3 insertions(+), 68 deletions(-)

diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
index a565617f21b..14815801d1e 100644
--- a/lib/Analysis/MemoryBuiltins.cpp
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -543,20 +543,9 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitLoadInst(LoadInst&) {
   return unknown();
 }
 
-SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode &PHI) {
-  if (PHI.getNumIncomingValues() == 0)
-    return unknown();
-
-  SizeOffsetType Ret = compute(PHI.getIncomingValue(0));
-  if (!bothKnown(Ret))
-    return unknown();
-
-  // verify that all PHI incoming pointers have the same size and offset
-  for (unsigned i = 1, e = PHI.getNumIncomingValues(); i != e; ++i) {
-    if (compute(PHI.getIncomingValue(i)) != Ret)
-      return unknown();
-  }
-  return Ret;
+SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode&) {
+  // too complex to analyze statically.
+  return unknown();
 }
 
 SizeOffsetType ObjectSizeOffsetVisitor::visitSelectInst(SelectInst &I) {
diff --git a/test/Transforms/InstCombine/objsize.ll b/test/Transforms/InstCombine/objsize.ll
index de8ac97b6f5..31a3cb46e45 100644
--- a/test/Transforms/InstCombine/objsize.ll
+++ b/test/Transforms/InstCombine/objsize.ll
@@ -256,57 +256,3 @@ xpto:
 return:
   ret i32 7
 }
-
-declare noalias i8* @valloc(i32) nounwind
-
-; CHECK: @test14
-; CHECK: ret i32 6
-define i32 @test14(i32 %a) nounwind {
-  switch i32 %a, label %sw.default [
-    i32 1, label %sw.bb
-    i32 2, label %sw.bb1
-  ]
-
-sw.bb:
-  %call = tail call noalias i8* @malloc(i32 6) nounwind
-  br label %sw.epilog
-
-sw.bb1:
-  %call2 = tail call noalias i8* @calloc(i32 3, i32 2) nounwind
-  br label %sw.epilog
-
-sw.default:
-  %call3 = tail call noalias i8* @valloc(i32 6) nounwind
-  br label %sw.epilog
-
-sw.epilog:
-  %b.0 = phi i8* [ %call3, %sw.default ], [ %call2, %sw.bb1 ], [ %call, %sw.bb ]
-  %1 = tail call i32 @llvm.objectsize.i32(i8* %b.0, i1 false)
-  ret i32 %1
-}
-
-; CHECK: @test15
-; CHECK: llvm.objectsize
-define i32 @test15(i32 %a) nounwind {
-  switch i32 %a, label %sw.default [
-    i32 1, label %sw.bb
-    i32 2, label %sw.bb1
-  ]
-
-sw.bb:
-  %call = tail call noalias i8* @malloc(i32 3) nounwind
-  br label %sw.epilog
-
-sw.bb1:
-  %call2 = tail call noalias i8* @calloc(i32 2, i32 1) nounwind
-  br label %sw.epilog
-
-sw.default:
-  %call3 = tail call noalias i8* @valloc(i32 3) nounwind
-  br label %sw.epilog
-
-sw.epilog:
-  %b.0 = phi i8* [ %call3, %sw.default ], [ %call2, %sw.bb1 ], [ %call, %sw.bb ]
-  %1 = tail call i32 @llvm.objectsize.i32(i8* %b.0, i1 false)
-  ret i32 %1
-}