Modestas Valauskas
0bef837817
Stacks on top of the int.{trailingZeroBitCount,oneBitCount} API CL
(commit 754239b077). Both getters route through OTHER_RECOGNIZED_LIST
when a hardware fast path is available; otherwise the newly added
Dart bodies inline at call sites via vm:prefer-inline. The C++
natives are removed.
Backend codegen
---------------
ARM64: NEON CNT + UADDLV (popcount); RBIT + CLZ (ctz).
ARM: NEON CNT + VPADDL chain (popcount); RBIT + CLZ on the
register pair (ctz).
x64: popcntq when TargetCPUFeatures::popcnt_supported();
LoadImmediate(64) + rep_bsfq for ctz (decodes as tzcnt
on BMI1+, preserves dest on zero otherwise).
RISC-V 64: cpop / ctz when RV_baseline includes Zbb.
Per-arch availability is encapsulated in
UnaryInt64OpInstr::IsSupported(Token::Kind).
Apple M-series ARM64, AOT (us/iter, lower is better):
cardinality.swar 371
cardinality.accelerated 154 (2.4x)
forEachSetBit.swar 19031
forEachSetBit.accelerated 4988 (3.8x)
select.swar 199
select.accelerated 77 (2.6x)
complementCardinality.swar 399
complementCardinality.accel 152 (2.6x)
Work towards https://github.com/dart-lang/sdk/issues/6486 (popcount
and ctz intrinsification).
Work towards https://github.com/dart-lang/sdk/issues/1053 (efficient
BitSet implementation).
Fixes https://github.com/dart-lang/sdk/issues/52673
Fixes https://github.com/dart-lang/sdk/issues/38346
Issue https://github.com/dart-lang/sdk/issues/10212
Issue https://github.com/dart-lang/sdk/issues/5798
TEST=tests/corelib/int_bit_count_test
Cq-Include-Trybots: luci.dart.try:vm-aot-linux-release-simarm_x64-try,vm-aot-linux-debug-simarm_x64-try,dart-sdk-linux-riscv64-try
Change-Id: I9c2c4225fd63d54e190398a0fb6649366317dd17
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/504221
Commit-Queue: Slava Egorov <vegorov@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Auto-Submit: Modestas Valauskas <valauskasmodestas@gmail.com>
Dart VM Compilation Pipeline
This folder contains Dart VM compilation pipeline.
Compilation pipeline is mainly responsible for converting AST or Kernel AST into IL flow graphs and then generating native code from IL.
It has the following structure:
| Directory | What goes there |
|---|---|
assembler/ |
Assemblers and disassemblers |
backend/ |
IL based compilation backend: optimization passes and architecture specific code generation rules |
frontend/ |
Frontends responsible for converting AST into IL |
jit/ |
JIT specific passes and compilation pipeline entry points |
aot/ |
AOT specific passes and compilation pipeline entry points |
. |
Shared code or code without clear designation. |
Currently there are no layering restrictions and components from different subfolders can reference each other.