[LoopIdiom] Added testcase for double memset (fixed in LLVM 12); NFC

diff --git a/llvm/test/Transforms/LoopIdiom/memset.ll b/llvm/test/Transforms/LoopIdiom/memset.ll
new file mode 100644 (file)
index 0000000..ccf55c2
--- /dev/null
+++ b/llvm/test/Transforms/LoopIdiom/memset.ll
@@ -0,0 +1,48 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -basic-aa -loop-idiom < %s -S | FileCheck %s
+
+
+define dso_local void @double_memset(i8* nocapture %p, i8* noalias nocapture %q, i32 %n) {
+; CHECK-LABEL: @double_memset(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP4:%.*]] = icmp sgt i32 [[N:%.*]], 0
+; CHECK-NEXT:    br i1 [[CMP4]], label [[FOR_BODY_PREHEADER:%.*]], label [[FOR_COND_CLEANUP:%.*]]
+; CHECK:       for.body.preheader:
+; CHECK-NEXT:    [[TMP0:%.*]] = zext i32 [[N]] to i64
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i64(i8* align 1 [[Q:%.*]], i8 0, i64 [[TMP0]], i1 false)
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i32 [[N]] to i64
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i64(i8* align 1 [[P:%.*]], i8 0, i64 [[TMP1]], i1 false)
+; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
+; CHECK:       for.cond.cleanup.loopexit:
+; CHECK-NEXT:    br label [[FOR_COND_CLEANUP]]
+; CHECK:       for.cond.cleanup:
+; CHECK-NEXT:    ret void
+; CHECK:       for.body:
+; CHECK-NEXT:    [[I_07:%.*]] = phi i32 [ [[INC:%.*]], [[FOR_BODY]] ], [ 0, [[FOR_BODY_PREHEADER]] ]
+; CHECK-NEXT:    [[P_ADDR_06:%.*]] = phi i8* [ [[INCDEC_PTR1:%.*]], [[FOR_BODY]] ], [ [[P]], [[FOR_BODY_PREHEADER]] ]
+; CHECK-NEXT:    [[Q_ADDR_05:%.*]] = phi i8* [ [[INCDEC_PTR:%.*]], [[FOR_BODY]] ], [ [[Q]], [[FOR_BODY_PREHEADER]] ]
+; CHECK-NEXT:    [[INCDEC_PTR]] = getelementptr inbounds i8, i8* [[Q_ADDR_05]], i64 1
+; CHECK-NEXT:    [[INCDEC_PTR1]] = getelementptr inbounds i8, i8* [[P_ADDR_06]], i64 1
+; CHECK-NEXT:    [[INC]] = add nuw nsw i32 [[I_07]], 1
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i32 [[INC]], [[N]]
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP_LOOPEXIT:%.*]], label [[FOR_BODY]]
+;
+entry:
+  %cmp4 = icmp sgt i32 %n, 0
+  br i1 %cmp4, label %for.body, label %for.cond.cleanup
+
+for.cond.cleanup:
+  ret void
+
+for.body:
+  %i.07 = phi i32 [ %inc, %for.body ], [ 0, %entry ]
+  %p.addr.06 = phi i8* [ %incdec.ptr1, %for.body ], [ %p, %entry ]
+  %q.addr.05 = phi i8* [ %incdec.ptr, %for.body ], [ %q, %entry ]
+  %incdec.ptr = getelementptr inbounds i8, i8* %q.addr.05, i64 1
+  store i8 0, i8* %q.addr.05, align 1
+  %incdec.ptr1 = getelementptr inbounds i8, i8* %p.addr.06, i64 1
+  store i8 0, i8* %p.addr.06, align 1
+  %inc = add nuw nsw i32 %i.07, 1
+  %exitcond.not = icmp eq i32 %inc, %n
+  br i1 %exitcond.not, label %for.cond.cleanup, label %for.body
+}