Add a testcase for some past-the-end address subtleties.

llvm-svn: 174210

diff --git a/llvm/test/Transforms/InstSimplify/past-the-end.ll b/llvm/test/Transforms/InstSimplify/past-the-end.ll
new file mode 100644 (file)
index 0000000..075da4a
--- /dev/null
+++ b/llvm/test/Transforms/InstSimplify/past-the-end.ll
@@ -0,0 +1,77 @@
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+target datalayout = "p:32:32"
+
+; Check some past-the-end subtleties.
+
+@opte_a = global i32 0
+@opte_b = global i32 0
+
+; Comparing base addresses of two distinct globals. Never equal.
+
+define zeroext i1 @no_offsets() {
+  %t = icmp eq i32* @opte_a, @opte_b
+  ret i1 %t
+  ; CHECK: no_offsets(
+  ; CHECK: ret i1 false
+}
+
+; Comparing past-the-end addresses of two distinct globals. Never equal.
+
+define zeroext i1 @both_past_the_end() {
+  %x = getelementptr i32* @opte_a, i32 1
+  %y = getelementptr i32* @opte_b, i32 1
+  %t = icmp eq i32* %x, %y
+  ret i1 %t
+  ; CHECK: both_past_the_end(
+  ; CHECK-NOT: ret i1 true
+  ; TODO: refine this
+}
+
+; Comparing past-the-end addresses of one global to the base address
+; of another. Can't fold this.
+
+define zeroext i1 @just_one_past_the_end() {
+  %x = getelementptr i32* @opte_a, i32 1
+  %t = icmp eq i32* %x, @opte_b
+  ret i1 %t
+  ; CHECK: just_one_past_the_end(
+  ; CHECK: ret i1 icmp eq (i32* getelementptr inbounds (i32* @opte_a, i32 1), i32* @opte_b)
+}
+
+; Comparing base addresses of two distinct allocas. Never equal.
+
+define zeroext i1 @no_alloca_offsets() {
+  %m = alloca i32
+  %n = alloca i32
+  %t = icmp eq i32* %m, %n
+  ret i1 %t
+  ; CHECK: no_alloca_offsets(
+  ; CHECK: ret i1 false
+}
+
+; Comparing past-the-end addresses of two distinct allocas. Never equal.
+
+define zeroext i1 @both_past_the_end_alloca() {
+  %m = alloca i32
+  %n = alloca i32
+  %x = getelementptr i32* %m, i32 1
+  %y = getelementptr i32* %n, i32 1
+  %t = icmp eq i32* %x, %y
+  ret i1 %t
+  ; CHECK: both_past_the_end_alloca(
+  ; CHECK-NOT: ret i1 true
+  ; TODO: refine this
+}
+
+; Comparing past-the-end addresses of one alloca to the base address
+; of another. Can't fold this.
+
+define zeroext i1 @just_one_past_the_end_alloca() {
+  %m = alloca i32
+  %n = alloca i32
+  %x = getelementptr i32* %m, i32 1
+  %t = icmp eq i32* %x, %n
+  ret i1 %t
+  ; CHECK: just_one_past_the_end_alloca(
+  ; CHECK: ret i1 %t
+}