Reviewers: ulan,
Message:
Could you have a look?
Description:
Fix arm64 deoptimization from double registers (reverts r20613).
This reverts "ARM64: Use pair memory access in deoptimizer entry", r20613.
It
does not really make sense to micro-optimize the deoptimizer as it is the
ultra-slow path. Moreover, the original code was easier to read (in
addition to
being correct).
BUG=391313
LOG=N
Please review this at https://codereview.chromium.org/389583003/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+57, -41 lines):
M src/arm64/deoptimizer-arm64.cc
A test/mjsunit/regress/regress-381313.js
Index: src/arm64/deoptimizer-arm64.cc
diff --git a/src/arm64/deoptimizer-arm64.cc b/src/arm64/deoptimizer-arm64.cc
index
3451ef3c47306bad3ff4b84341612a1f95338ad2..712881d9db08f381145a6a9ef9912571eba6bb57
100644
--- a/src/arm64/deoptimizer-arm64.cc
+++ b/src/arm64/deoptimizer-arm64.cc
@@ -110,42 +110,6 @@ void
Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
}
-#define __ masm->
-
-static void CopyRegisterDumpToFrame(MacroAssembler* masm,
- Register frame,
- CPURegList reg_list,
- Register scratch1,
- Register scratch2,
- int src_offset,
- int dst_offset) {
- int offset0, offset1;
- CPURegList copy_to_input = reg_list;
- int reg_count = reg_list.Count();
- int reg_size = reg_list.RegisterSizeInBytes();
- for (int i = 0; i < (reg_count / 2); i++) {
- __ PeekPair(scratch1, scratch2, src_offset + (i * reg_size * 2));
-
- offset0 = (copy_to_input.PopLowestIndex().code() * reg_size) +
dst_offset;
- offset1 = (copy_to_input.PopLowestIndex().code() * reg_size) +
dst_offset;
-
- if ((offset0 + reg_size) == offset1) {
- // Registers are adjacent: store in pairs.
- __ Stp(scratch1, scratch2, MemOperand(frame, offset0));
- } else {
- // Registers are not adjacent: store individually.
- __ Str(scratch1, MemOperand(frame, offset0));
- __ Str(scratch2, MemOperand(frame, offset1));
- }
- }
- if ((reg_count & 1) != 0) {
- __ Peek(scratch1, src_offset + (reg_count - 1) * reg_size);
- offset0 = (copy_to_input.PopLowestIndex().code() * reg_size) +
dst_offset;
- __ Str(scratch1, MemOperand(frame, offset0));
- }
-}
-
-#undef __
#define __ masm()->
@@ -209,13 +173,23 @@ void Deoptimizer::EntryGenerator::Generate() {
__ Ldr(x1, MemOperand(deoptimizer, Deoptimizer::input_offset()));
// Copy core registers into the input frame.
- CopyRegisterDumpToFrame(masm(), x1, saved_registers, x2, x4, 0,
- FrameDescription::registers_offset());
+ CPURegList copy_to_input = saved_registers;
+ for (int i = 0; i < saved_registers.Count(); i++) {
+ __ Peek(x2, i * kPointerSize);
+ CPURegister current_reg = copy_to_input.PopLowestIndex();
+ int offset = (current_reg.code() * kPointerSize) +
+ FrameDescription::registers_offset();
+ __ Str(x2, MemOperand(x1, offset));
+ }
// Copy FP registers to the input frame.
- CopyRegisterDumpToFrame(masm(), x1, saved_fp_registers, x2, x4,
- kFPRegistersOffset,
- FrameDescription::double_registers_offset());
+ for (int i = 0; i < saved_fp_registers.Count(); i++) {
+ int dst_offset = FrameDescription::double_registers_offset() +
+ (i * kDoubleSize);
+ int src_offset = kFPRegistersOffset + (i * kDoubleSize);
+ __ Peek(x2, src_offset);
+ __ Str(x2, MemOperand(x1, dst_offset));
+ }
// Remove the bailout id and the saved registers from the stack.
__ Drop(1 + (kSavedRegistersAreaSize / kXRegSize));
Index: test/mjsunit/regress/regress-381313.js
diff --git a/test/mjsunit/regress/regress-381313.js
b/test/mjsunit/regress/regress-381313.js
new file mode 100644
index
0000000000000000000000000000000000000000..d2b9d7c11d3c12e77ce45169e3b271d402c3ad7e
--- /dev/null
+++ b/test/mjsunit/regress/regress-381313.js
@@ -0,0 +1,42 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+var g = 0;
+
+function f(x, deopt) {
+ var a0 = x;
+ var a1 = 2 * x;
+ var a2 = 3 * x;
+ var a3 = 4 * x;
+ var a4 = 5 * x;
+ var a5 = 6 * x;
+ var a6 = 7 * x;
+ var a7 = 8 * x;
+ var a8 = 9 * x;
+ var a9 = 10 * x;
+ var a10 = 11 * x;
+ var a11 = 12 * x;
+ var a12 = 13 * x;
+ var a13 = 14 * x;
+ var a14 = 15 * x;
+ var a15 = 16 * x;
+ var a16 = 17 * x;
+ var a17 = 18 * x;
+ var a18 = 19 * x;
+ var a19 = 20 * x;
+
+ g = 1;
+
+ deopt + 0;
+
+ return a0 + a1 + a2 + a3 + a4 + a5 + a6 + a7 + a8 + a9 +
+ a10 + a11 + a12 + a13 + a14 + a15 + a16 + a17 + a18 + a19;
+}
+
+f(0.5, 0);
+f(0.5, 0);
+%OptimizeFunctionOnNextCall(f);
+print(f(0.5, ""));
--
--
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