Fix a integer overflow in SimplifyCFG's look up table formation logic.

If the width is very large it gets truncated from uint64_t to uint32_t when
passed to TD->fitsInLegalInteger. The truncated value can fit in a register.
This manifested in massive memory usage or crashes (PR13946).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164784 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Benjamin Kramer
2012-09-27 18:29:58 +00:00
parent 593c0b08e6
commit 465251a7ce
2 changed files with 42 additions and 0 deletions
@@ -231,3 +231,41 @@ lor.end:
; CHECK-NEXT: %lor.ext = zext i1 %1 to i32
; CHECK-NEXT: ret i32 %lor.ext
}
; PR13946
define i32 @overflow(i32 %type) nounwind {
entry:
switch i32 %type, label %sw.default [
i32 -2147483648, label %sw.bb
i32 0, label %sw.bb
i32 1, label %sw.bb1
i32 2, label %sw.bb2
i32 -2147483645, label %sw.bb3
i32 3, label %sw.bb3
]
sw.bb:
br label %if.end
sw.bb1:
br label %if.end
sw.bb2:
br label %if.end
sw.bb3:
br label %if.end
sw.default:
br label %if.end
if.else:
br label %if.end
if.end:
%dirent_type.0 = phi i32 [ 3, %sw.default ], [ 6, %sw.bb3 ], [ 5, %sw.bb2 ], [ 0, %sw.bb1 ], [ 3, %sw.bb ], [ 0, %if.else ]
ret i32 %dirent_type.0
; CHECK: define i32 @overflow
; CHECK: switch
; CHECK: phi
}