1 files changed, 35 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/cast3.ll b/test/Transforms/InstCombine/cast3.ll
new file mode 100644
index 0000000..bc60f55
--- /dev/null
+++ b/test/Transforms/InstCombine/cast3.ll
@@ -0,0 +1,35 @@
+; RUN: opt < %s -instcombine -S | not grep getelementptr
+; PR2831
+
+; Don't raise arbitrary inttoptr+arithmetic+ptrtoint to getelementptr.
+
+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-f80:32:32"
+
+define i32 @main(i32 %argc, i8** %argv) nounwind {
+entry:
+	%0 = ptrtoint i8** %argv to i32		; <i32> [#uses=1]
+	%1 = add i32 %0, 1		; <i32> [#uses=1]
+	ret i32 %1
+}
+
+; This testcase could theoretically be optimized down to return zero,
+; but for now being conservative with ptrtoint/inttoptr is fine.
+define i32 @a() nounwind {
+entry:
+	%b = alloca i32		; <i32*> [#uses=3]
+	%a = alloca i32		; <i32*> [#uses=2]
+	%"alloca point" = bitcast i32 0 to i32		; <i32> [#uses=0]
+	store i32 1, i32* %b, align 4
+	%a1 = ptrtoint i32* %a to i32		; <i32> [#uses=1]
+	%b4 = ptrtoint i32* %b to i32		; <i32> [#uses=1]
+	%a7 = ptrtoint i32* %a to i32		; <i32> [#uses=1]
+	%0 = sub i32 %b4, %a7		; <i32> [#uses=1]
+	%1 = add i32 %a1, %0		; <i32> [#uses=1]
+	%2 = inttoptr i32 %1 to i32*		; <i32*> [#uses=1]
+	store i32 0, i32* %2, align 4
+	%3 = load i32* %b, align 4		; <i32> [#uses=1]
+	br label %return
+
+return:		; preds = %entry
+	ret i32 %3
+}