llvm/unittests/Target/AArch64/DecomposeStackOffsetTest.cpp

   1 //===- TestStackOffset.cpp - StackOffset unit tests------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/Support/TypeSize.h"
  10 #include "AArch64InstrInfo.h"
  11 #include "gtest/gtest.h"
  12
  13 using namespace llvm;
  14
  15 TEST(StackOffset, decomposeStackOffsetForFrameOffsets) {
  16   StackOffset A = StackOffset::getFixed(8);
  17   StackOffset B = StackOffset::getFixed(4);
  18   StackOffset C = StackOffset::getScalable(16);
  19
  20   // If all offsets can be materialized with only ADDVL,
  21   // make sure PLSized is 0.
  22   int64_t ByteSized, VLSized, PLSized;
  23   AArch64InstrInfo::decomposeStackOffsetForFrameOffsets(A + B + C, ByteSized, PLSized,
  24                                             VLSized);
  25   EXPECT_EQ(12, ByteSized);
  26   EXPECT_EQ(1, VLSized);
  27   EXPECT_EQ(0, PLSized);
  28
  29   // If we need an ADDPL to materialize the offset, and the number of scalable
  30   // bytes fits the ADDPL immediate, fold the scalable bytes to fit in PLSized.
  31   StackOffset D = StackOffset::getScalable(2);
  32   AArch64InstrInfo::decomposeStackOffsetForFrameOffsets(C + D, ByteSized, PLSized, VLSized);
  33   EXPECT_EQ(0, ByteSized);
  34   EXPECT_EQ(0, VLSized);
  35   EXPECT_EQ(9, PLSized);
  36
  37   StackOffset E = StackOffset::getScalable(64);
  38   StackOffset F = StackOffset::getScalable(2);
  39   AArch64InstrInfo::decomposeStackOffsetForFrameOffsets(E + F, ByteSized, PLSized, VLSized);
  40   EXPECT_EQ(0, ByteSized);
  41   EXPECT_EQ(0, VLSized);
  42   EXPECT_EQ(33, PLSized);
  43
  44   // If the offset requires an ADDPL instruction to materialize, and would
  45   // require more than two instructions, decompose it into both
  46   // ADDVL (n x 16 bytes) and ADDPL (n x 2 bytes) instructions.
  47   StackOffset G = StackOffset::getScalable(128);
  48   StackOffset H = StackOffset::getScalable(2);
  49   AArch64InstrInfo::decomposeStackOffsetForFrameOffsets(G + H, ByteSized, PLSized, VLSized);
  50   EXPECT_EQ(0, ByteSized);
  51   EXPECT_EQ(8, VLSized);
  52   EXPECT_EQ(1, PLSized);
  53 }