From ba89c34e94a82f0a6904dcc62caa6aa7bb14c12c Mon Sep 17 00:00:00 2001
From: Tijana Jakovljevic <tijana.jakovljevic@imgtec.com>
Date: Fri, 10 Mar 2017 13:36:08 +0100
Subject: MIPS64: Improve storing of constants in fields and array elements

Test: booted MIPS64 in QEMU
Test: mma test-art-target-run-test
Test: mma test-art-host-gtest-assembler_mips64_test

Change-Id: I8e0002166174eebea1309358eb9d96f34eee3225
---
 compiler/utils/mips64/assembler_mips64.h | 80 ++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

(limited to 'compiler/utils/mips64/assembler_mips64.h')

diff --git a/compiler/utils/mips64/assembler_mips64.h b/compiler/utils/mips64/assembler_mips64.h
index 8bbe862d19..b98db65fbd 100644
--- a/compiler/utils/mips64/assembler_mips64.h
+++ b/compiler/utils/mips64/assembler_mips64.h
@@ -781,6 +781,86 @@ class Mips64Assembler FINAL : public Assembler, public JNIMacroAssembler<Pointer
   };
 
  public:
+  template <typename ImplicitNullChecker = NoImplicitNullChecker>
+  void StoreConstToOffset(StoreOperandType type,
+                          int64_t value,
+                          GpuRegister base,
+                          int32_t offset,
+                          GpuRegister temp,
+                          ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
+    // We permit `base` and `temp` to coincide (however, we check that neither is AT),
+    // in which case the `base` register may be overwritten in the process.
+    CHECK_NE(temp, AT);  // Must not use AT as temp, so as not to overwrite the adjusted base.
+    if (!IsInt<16>(offset) ||
+        (type == kStoreDoubleword && !IsAligned<kMips64DoublewordSize>(offset) &&
+         !IsInt<16>(static_cast<int32_t>(offset + kMips64WordSize)))) {
+      LoadConst32(AT, offset & ~(kMips64DoublewordSize - 1));
+      Daddu(AT, AT, base);
+      base = AT;
+      offset &= (kMips64DoublewordSize - 1);
+    }
+    GpuRegister reg;
+    // If the adjustment left `base` unchanged and equal to `temp`, we can't use `temp`
+    // to load and hold the value but we can use AT instead as AT hasn't been used yet.
+    // Otherwise, `temp` can be used for the value. And if `temp` is the same as the
+    // original `base` (that is, `base` prior to the adjustment), the original `base`
+    // register will be overwritten.
+    if (base == temp) {
+      temp = AT;
+    }
+
+    if (type == kStoreDoubleword && IsAligned<kMips64DoublewordSize>(offset)) {
+      if (value == 0) {
+        reg = ZERO;
+      } else {
+        reg = temp;
+        LoadConst64(reg, value);
+      }
+      Sd(reg, base, offset);
+      null_checker();
+    } else {
+      uint32_t low = Low32Bits(value);
+      uint32_t high = High32Bits(value);
+      if (low == 0) {
+        reg = ZERO;
+      } else {
+        reg = temp;
+        LoadConst32(reg, low);
+      }
+      switch (type) {
+        case kStoreByte:
+          Sb(reg, base, offset);
+          break;
+        case kStoreHalfword:
+          Sh(reg, base, offset);
+          break;
+        case kStoreWord:
+          Sw(reg, base, offset);
+          break;
+        case kStoreDoubleword:
+          // not aligned to kMips64DoublewordSize
+          CHECK_ALIGNED(offset, kMips64WordSize);
+          Sw(reg, base, offset);
+          null_checker();
+          if (high == 0) {
+            reg = ZERO;
+          } else {
+            reg = temp;
+            if (high != low) {
+              LoadConst32(reg, high);
+            }
+          }
+          Sw(reg, base, offset + kMips64WordSize);
+          break;
+        default:
+          LOG(FATAL) << "UNREACHABLE";
+      }
+      if (type != kStoreDoubleword) {
+        null_checker();
+      }
+    }
+  }
+
   template <typename ImplicitNullChecker = NoImplicitNullChecker>
   void LoadFromOffset(LoadOperandType type,
                       GpuRegister reg,
-- 
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