Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 217 insertions, 0 deletions

diff --git a/js/src/jit/riscv64/AssemblerMatInt.cpp b/js/src/jit/riscv64/AssemblerMatInt.cpp
new file mode 100644
index 0000000000..81c7fa7c40
--- /dev/null
+++ b/js/src/jit/riscv64/AssemblerMatInt.cpp
@@ -0,0 +1,217 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+//===- RISCVMatInt.cpp - Immediate materialisation -------------*- C++
+//-*--===//
+//
+//  Part of the LLVM Project, under the Apache License v2.0 with LLVM
+//  Exceptions. See https://llvm.org/LICENSE.txt for license information.
+//  SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/Maybe.h"
+
+#include "gc/Marking.h"
+#include "jit/AutoWritableJitCode.h"
+#include "jit/ExecutableAllocator.h"
+#include "jit/riscv64/Assembler-riscv64.h"
+#include "jit/riscv64/disasm/Disasm-riscv64.h"
+#include "vm/Realm.h"
+namespace js {
+namespace jit {
+void Assembler::RecursiveLi(Register rd, int64_t val) {
+  if (val > 0 && RecursiveLiImplCount(val) > 2) {
+    unsigned LeadingZeros = mozilla::CountLeadingZeroes64((uint64_t)val);
+    uint64_t ShiftedVal = (uint64_t)val << LeadingZeros;
+    int countFillZero = RecursiveLiImplCount(ShiftedVal) + 1;
+    if (countFillZero < RecursiveLiImplCount(val)) {
+      RecursiveLiImpl(rd, ShiftedVal);
+      srli(rd, rd, LeadingZeros);
+      return;
+    }
+  }
+  RecursiveLiImpl(rd, val);
+}
+
+int Assembler::RecursiveLiCount(int64_t val) {
+  if (val > 0 && RecursiveLiImplCount(val) > 2) {
+    unsigned LeadingZeros = mozilla::CountLeadingZeroes64((uint64_t)val);
+    uint64_t ShiftedVal = (uint64_t)val << LeadingZeros;
+    // Fill in the bits that will be shifted out with 1s. An example where
+    // this helps is trailing one masks with 32 or more ones. This will
+    // generate ADDI -1 and an SRLI.
+    int countFillZero = RecursiveLiImplCount(ShiftedVal) + 1;
+    if (countFillZero < RecursiveLiImplCount(val)) {
+      return countFillZero;
+    }
+  }
+  return RecursiveLiImplCount(val);
+}
+
+inline int64_t signExtend(uint64_t V, int N) {
+  return int64_t(V << (64 - N)) >> (64 - N);
+}
+
+void Assembler::RecursiveLiImpl(Register rd, int64_t Val) {
+  if (is_int32(Val)) {
+    // Depending on the active bits in the immediate Value v, the following
+    // instruction sequences are emitted:
+    //
+    // v == 0                        : ADDI
+    // v[0,12) != 0 && v[12,32) == 0 : ADDI
+    // v[0,12) == 0 && v[12,32) != 0 : LUI
+    // v[0,32) != 0                  : LUI+ADDI(W)
+    int64_t Hi20 = ((Val + 0x800) >> 12) & 0xFFFFF;
+    int64_t Lo12 = Val << 52 >> 52;
+
+    if (Hi20) {
+      lui(rd, (int32_t)Hi20);
+    }
+
+    if (Lo12 || Hi20 == 0) {
+      if (Hi20) {
+        addiw(rd, rd, Lo12);
+      } else {
+        addi(rd, zero_reg, Lo12);
+      }
+    }
+    return;
+  }
+
+  // In the worst case, for a full 64-bit constant, a sequence of 8
+  // instructions (i.e., LUI+ADDIW+SLLI+ADDI+SLLI+ADDI+SLLI+ADDI) has to be
+  // emitted. Note that the first two instructions (LUI+ADDIW) can contribute
+  // up to 32 bits while the following ADDI instructions contribute up to 12
+  // bits each.
+  //
+  // On the first glance, implementing this seems to be possible by simply
+  // emitting the most significant 32 bits (LUI+ADDIW) followed by as many
+  // left shift (SLLI) and immediate additions (ADDI) as needed. However, due
+  // to the fact that ADDI performs a sign extended addition, doing it like
+  // that would only be possible when at most 11 bits of the ADDI instructions
+  // are used. Using all 12 bits of the ADDI instructions, like done by GAS,
+  // actually requires that the constant is processed starting with the least
+  // significant bit.
+  //
+  // In the following, constants are processed from LSB to MSB but instruction
+  // emission is performed from MSB to LSB by recursively calling
+  // generateInstSeq. In each recursion, first the lowest 12 bits are removed
+  // from the constant and the optimal shift amount, which can be greater than
+  // 12 bits if the constant is sparse, is determined. Then, the shifted
+  // remaining constant is processed recursively and gets emitted as soon as
+  // it fits into 32 bits. The emission of the shifts and additions is
+  // subsequently performed when the recursion returns.
+
+  int64_t Lo12 = Val << 52 >> 52;
+  int64_t Hi52 = ((uint64_t)Val + 0x800ull) >> 12;
+  int ShiftAmount = 12 + mozilla::CountTrailingZeroes64((uint64_t)Hi52);
+  Hi52 = signExtend(Hi52 >> (ShiftAmount - 12), 64 - ShiftAmount);
+
+  // If the remaining bits don't fit in 12 bits, we might be able to reduce
+  // the shift amount in order to use LUI which will zero the lower 12 bits.
+  bool Unsigned = false;
+  if (ShiftAmount > 12 && !is_int12(Hi52)) {
+    if (is_int32((uint64_t)Hi52 << 12)) {
+      // Reduce the shift amount and add zeros to the LSBs so it will match
+      // LUI.
+      ShiftAmount -= 12;
+      Hi52 = (uint64_t)Hi52 << 12;
+    }
+  }
+  RecursiveLi(rd, Hi52);
+
+  if (Unsigned) {
+  } else {
+    slli(rd, rd, ShiftAmount);
+  }
+  if (Lo12) {
+    addi(rd, rd, Lo12);
+  }
+}
+
+int Assembler::RecursiveLiImplCount(int64_t Val) {
+  int count = 0;
+  if (is_int32(Val)) {
+    // Depending on the active bits in the immediate Value v, the following
+    // instruction sequences are emitted:
+    //
+    // v == 0                        : ADDI
+    // v[0,12) != 0 && v[12,32) == 0 : ADDI
+    // v[0,12) == 0 && v[12,32) != 0 : LUI
+    // v[0,32) != 0                  : LUI+ADDI(W)
+    int64_t Hi20 = ((Val + 0x800) >> 12) & 0xFFFFF;
+    int64_t Lo12 = Val << 52 >> 52;
+
+    if (Hi20) {
+      // lui(rd, (int32_t)Hi20);
+      count++;
+    }
+
+    if (Lo12 || Hi20 == 0) {
+      //   unsigned AddiOpc = (IsRV64 && Hi20) ? RISCV::ADDIW : RISCV::ADDI;
+      //   Res.push_back(RISCVMatInt::Inst(AddiOpc, Lo12));
+      count++;
+    }
+    return count;
+  }
+
+  // In the worst case, for a full 64-bit constant, a sequence of 8
+  // instructions (i.e., LUI+ADDIW+SLLI+ADDI+SLLI+ADDI+SLLI+ADDI) has to be
+  // emitted. Note that the first two instructions (LUI+ADDIW) can contribute
+  // up to 32 bits while the following ADDI instructions contribute up to 12
+  // bits each.
+  //
+  // On the first glance, implementing this seems to be possible by simply
+  // emitting the most significant 32 bits (LUI+ADDIW) followed by as many
+  // left shift (SLLI) and immediate additions (ADDI) as needed. However, due
+  // to the fact that ADDI performs a sign extended addition, doing it like
+  // that would only be possible when at most 11 bits of the ADDI instructions
+  // are used. Using all 12 bits of the ADDI instructions, like done by GAS,
+  // actually requires that the constant is processed starting with the least
+  // significant bit.
+  //
+  // In the following, constants are processed from LSB to MSB but instruction
+  // emission is performed from MSB to LSB by recursively calling
+  // generateInstSeq. In each recursion, first the lowest 12 bits are removed
+  // from the constant and the optimal shift amount, which can be greater than
+  // 12 bits if the constant is sparse, is determined. Then, the shifted
+  // remaining constant is processed recursively and gets emitted as soon as
+  // it fits into 32 bits. The emission of the shifts and additions is
+  // subsequently performed when the recursion returns.
+
+  int64_t Lo12 = Val << 52 >> 52;
+  int64_t Hi52 = ((uint64_t)Val + 0x800ull) >> 12;
+  int ShiftAmount = 12 + mozilla::CountTrailingZeroes64((uint64_t)Hi52);
+  Hi52 = signExtend(Hi52 >> (ShiftAmount - 12), 64 - ShiftAmount);
+
+  // If the remaining bits don't fit in 12 bits, we might be able to reduce
+  // the shift amount in order to use LUI which will zero the lower 12 bits.
+  bool Unsigned = false;
+  if (ShiftAmount > 12 && !is_int12(Hi52)) {
+    if (is_int32((uint64_t)Hi52 << 12)) {
+      // Reduce the shift amount and add zeros to the LSBs so it will match
+      // LUI.
+      ShiftAmount -= 12;
+      Hi52 = (uint64_t)Hi52 << 12;
+    }
+  }
+
+  count += RecursiveLiImplCount(Hi52);
+
+  if (Unsigned) {
+  } else {
+    // slli(rd, rd, ShiftAmount);
+    count++;
+  }
+  if (Lo12) {
+    // addi(rd, rd, Lo12);
+    count++;
+  }
+  return count;
+}
+
+}  // namespace jit
+}  // namespace js