Revert the addition of hasNoPointerOverflow to GEPOperator.

Getelementptrs that are defined to wrap are virtually useless to
optimization, and getelementptrs that are undefined on any kind
of overflow are too restrictive -- it's difficult to ensure that
all intermediate addresses are within bounds. I'm going to take
a different approach.

Remove a few optimizations that depended on this flag.

llvm-svn: 76437

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/add3.ll b/llvm/test/Transforms/InstCombine/add3.ll
new file mode 100644
index 00000000000..55e7ec7a1db
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/add3.ll
@@ -0,0 +1,21 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep inttoptr | count 2
+
+;; Target triple for gep raising case below.
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i686-apple-darwin8"
+
+; PR1795
+define void @test2(i32 %.val24) {
+EntryBlock:
+        add i32 %.val24, -12
+        inttoptr i32 %0 to i32*
+        store i32 1, i32* %1
+        add i32 %.val24, -16
+        inttoptr i32 %2 to i32*
+        getelementptr i32* %3, i32 1
+        load i32* %4
+        tail call i32 @callee( i32 %5 )
+        ret void
+}
+
+declare i32 @callee(i32)