[LV] Add coverage for fixing-up scalar resume values (#160492)
Increase coverage of the routine fixScalarResumeValuesFromBypass in the
case where the original scalar resume value is zero.
Co-authored-by: Florian Hahn <flo@fhahn.com>
diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/epilogue-vectorization-fix-scalar-resume-values.ll b/llvm/test/Transforms/LoopVectorize/AArch64/epilogue-vectorization-fix-scalar-resume-values.ll
new file mode 100644
index 0000000..f5e3b55
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/epilogue-vectorization-fix-scalar-resume-values.ll
@@ -0,0 +1,76 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals none --version 6
+; RUN: opt -passes=loop-vectorize -S %s | FileCheck %s
+
+; This tests exercises the out-of-band fixing-up of scalar resume values.
+
+target triple = "aarch64"
+
+define void @epilogue_vectorization_fix_scalar_resume_values(ptr %dst, i64 %n) {
+; CHECK-LABEL: define void @epilogue_vectorization_fix_scalar_resume_values(
+; CHECK-SAME: ptr [[DST:%.*]], i64 [[N:%.*]]) {
+; CHECK-NEXT: [[ITER_CHECK:.*]]:
+; CHECK-NEXT: [[REM:%.*]] = urem i64 [[N]], 3
+; CHECK-NEXT: br i1 true, label %[[VEC_EPILOG_SCALAR_PH:.*]], label %[[VECTOR_MAIN_LOOP_ITER_CHECK:.*]]
+; CHECK: [[VECTOR_MAIN_LOOP_ITER_CHECK]]:
+; CHECK-NEXT: br i1 true, label %[[VEC_EPILOG_PH:.*]], label %[[VECTOR_PH:.*]]
+; CHECK: [[VECTOR_PH]]:
+; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 [[REM]], 32
+; CHECK-NEXT: [[N_VEC:%.*]] = sub i64 [[REM]], [[N_MOD_VF]]
+; CHECK-NEXT: br label %[[VECTOR_BODY:.*]]
+; CHECK: [[VECTOR_BODY]]:
+; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
+; CHECK-NEXT: [[TMP0:%.*]] = getelementptr i8, ptr [[DST]], i64 [[INDEX]]
+; CHECK-NEXT: [[TMP1:%.*]] = getelementptr i8, ptr [[TMP0]], i32 16
+; CHECK-NEXT: store <16 x i8> zeroinitializer, ptr [[TMP0]], align 1
+; CHECK-NEXT: store <16 x i8> zeroinitializer, ptr [[TMP1]], align 1
+; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 32
+; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
+; CHECK-NEXT: br i1 [[TMP2]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK: [[MIDDLE_BLOCK]]:
+; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 [[REM]], [[N_VEC]]
+; CHECK-NEXT: br i1 [[CMP_N]], label %[[EXIT:.*]], label %[[VEC_EPILOG_ITER_CHECK:.*]]
+; CHECK: [[VEC_EPILOG_ITER_CHECK]]:
+; CHECK-NEXT: [[N_VEC_REMAINING:%.*]] = sub i64 [[REM]], [[N_VEC]]
+; CHECK-NEXT: [[MIN_EPILOG_ITERS_CHECK:%.*]] = icmp ult i64 [[N_VEC_REMAINING]], 8
+; CHECK-NEXT: br i1 [[MIN_EPILOG_ITERS_CHECK]], label %[[VEC_EPILOG_SCALAR_PH]], label %[[VEC_EPILOG_PH]], !prof [[PROF3:![0-9]+]]
+; CHECK: [[VEC_EPILOG_PH]]:
+; CHECK-NEXT: [[VEC_EPILOG_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], %[[VEC_EPILOG_ITER_CHECK]] ], [ 0, %[[VECTOR_MAIN_LOOP_ITER_CHECK]] ]
+; CHECK-NEXT: br label %[[VEC_EPILOG_VECTOR_BODY:.*]]
+; CHECK: [[VEC_EPILOG_VECTOR_BODY]]:
+; CHECK-NEXT: [[INDEX1:%.*]] = phi i64 [ [[VEC_EPILOG_RESUME_VAL]], %[[VEC_EPILOG_PH]] ], [ [[INDEX_NEXT2:%.*]], %[[VEC_EPILOG_VECTOR_BODY]] ]
+; CHECK-NEXT: [[TMP3:%.*]] = getelementptr i8, ptr [[DST]], i64 [[INDEX1]]
+; CHECK-NEXT: store <8 x i8> zeroinitializer, ptr [[TMP3]], align 1
+; CHECK-NEXT: [[INDEX_NEXT2]] = add nuw i64 [[INDEX1]], 8
+; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i64 [[INDEX_NEXT2]], 0
+; CHECK-NEXT: br i1 [[TMP4]], label %[[VEC_EPILOG_MIDDLE_BLOCK:.*]], label %[[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP4:![0-9]+]]
+; CHECK: [[VEC_EPILOG_MIDDLE_BLOCK]]:
+; CHECK-NEXT: [[CMP_N3:%.*]] = icmp eq i64 [[REM]], 0
+; CHECK-NEXT: br i1 [[CMP_N3]], label %[[EXIT]], label %[[VEC_EPILOG_SCALAR_PH]]
+; CHECK: [[VEC_EPILOG_SCALAR_PH]]:
+; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 0, %[[VEC_EPILOG_MIDDLE_BLOCK]] ], [ [[N_VEC]], %[[VEC_EPILOG_ITER_CHECK]] ], [ 0, %[[ITER_CHECK]] ]
+; CHECK-NEXT: br label %[[LOOP:.*]]
+; CHECK: [[LOOP]]:
+; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], %[[VEC_EPILOG_SCALAR_PH]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
+; CHECK-NEXT: [[GEP_DST_IV:%.*]] = getelementptr i8, ptr [[DST]], i64 [[IV]]
+; CHECK-NEXT: store i8 0, ptr [[GEP_DST_IV]], align 1
+; CHECK-NEXT: [[IV_NEXT]] = add i64 [[IV]], 1
+; CHECK-NEXT: [[EXIT_COND:%.*]] = icmp eq i64 [[IV_NEXT]], [[REM]]
+; CHECK-NEXT: br i1 [[EXIT_COND]], label %[[EXIT]], label %[[LOOP]], !llvm.loop [[LOOP5:![0-9]+]]
+; CHECK: [[EXIT]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ %rem = urem i64 %n, 3
+ br label %loop
+
+loop:
+ %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+ %gep.dst.iv = getelementptr i8, ptr %dst, i64 %iv
+ store i8 0, ptr %gep.dst.iv, align 1
+ %iv.next = add i64 %iv, 1
+ %exit.cond = icmp eq i64 %iv.next, %rem
+ br i1 %exit.cond, label %exit, label %loop
+
+exit:
+ ret void
+}
