[SCCP] Add test where dereferenceable ptr is replaced with un-dereferenceable one

diff --git a/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll b/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll
new file mode 100644 (file)
index 0000000..5857ce2
--- /dev/null
+++ b/llvm/test/Transforms/SCCP/replace-dereferenceable-ptr-with-undereferenceable.ll
@@ -0,0 +1,86 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -ipsccp -S %s | FileCheck %s
+
+@y = common global [1 x i32] zeroinitializer, align 4
+@x = common global [1 x i32] zeroinitializer, align 4
+
+define i32 @eq_undereferenceable(i32* %p) {
+; CHECK-LABEL: @eq_undereferenceable(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    store i32 1, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32* [[P:%.*]], getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1)
+; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i32 2, i32* getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1), align 4
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4
+; CHECK-NEXT:    ret i32 [[TMP0]]
+;
+entry:
+  store i32 1, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4
+  %cmp = icmp eq i32* %p, getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1)
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  store i32 2, i32* %p, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  %0 = load i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4
+  ret i32 %0
+}
+
+
+define i32 @eq_dereferenceable(i32* %p) {
+; CHECK-LABEL: @eq_dereferenceable(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    store i32 1, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32* [[P:%.*]], getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0)
+; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i32 2, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), align 4
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4
+; CHECK-NEXT:    ret i32 [[TMP0]]
+;
+entry:
+  store i32 1, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4
+  %cmp = icmp eq i32* %p, getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 0)
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  store i32 2, i32* %p, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  %0 = load i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0), align 4
+  ret i32 %0
+}
+
+define i1 @eq_undereferenceable_cmp_simp(i32* %p) {
+; CHECK-LABEL: @eq_undereferenceable_cmp_simp(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP_0:%.*]] = icmp eq i32* [[P:%.*]], getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1)
+; CHECK-NEXT:    br i1 [[CMP_0]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i32 2, i32* getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1), align 4
+; CHECK-NEXT:    ret i1 true
+; CHECK:       if.end:
+; CHECK-NEXT:    [[CMP_2:%.*]] = icmp eq i32* [[P]], getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1)
+; CHECK-NEXT:    ret i1 [[CMP_2]]
+;
+entry:
+  %cmp.0 = icmp eq i32* %p, getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1)
+  br i1 %cmp.0, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  store i32 2, i32* %p, align 4
+  %cmp.1 = icmp eq i32* %p, getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1)
+  ret i1 %cmp.1
+
+if.end:                                           ; preds = %if.then, %entry
+  %cmp.2 = icmp eq i32* %p, getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1)
+  ret i1 %cmp.2
+}