Extend basic block without aggressive memory copy #121

qwe661234 · 2023-04-04T15:50:55Z

Due to the significant overhead associated with using aggressive memory copy, we opted to use a pointer to the IR of the basic block we intend to merge, rather than copying the IR to the basic block we wish to extend.

The performance results obtained from running CoreMark using different implementation strategies for EBB are presented below. As we can see, aggressive memory copy substantially degrades performance.

Model: Core i7-8700

Test	aggressive memcpy	Compiler	Iterations / Sec	Speedup
BB		clang-15	971.951
BB		gcc-12	963.336
EBB	O	clang-15	1013.070	+4.2%
EBB	O	gcc-12	1020.391	+6%
EBB	X	clang-15	1160.894	+19.4%
EBB	X	gcc-12	1167.938	+21.2%

src/decode.h

jserv

Improve git commit message. Always mention "IR" in capitalized form. You shall show explicit numbers about memory consumption and potential benefits.

src/emulate.c

src/decode.h

src/emulate.c

src/decode.h

src/emulate.c

Due to the significant overhead associated with using aggressive memory copy, we opted to use a pointer to the begin of IR array of the basic block we intend to merge, rather than copying whole IR array to the basic block we wish to extend. The performance results obtained from running CoreMark using different implementation strategies for EBB are presented below. As we can see, aggressive memory copy substantially degrades performance. |Test| aggressive memcpy|Compiler | Iterations / Sec |Speedup| |----+------------------+---------+------------------+-------| | BB | |clang-15 | 971.951 | | |----+------------------+---------+------------------+-------| | BB | | gcc-12 | 963.336 | | |----+------------------+---------+------------------+-------| | EBB| O |clang-15 | 1013.070 | +4.2% | |----+------------------+---------+------------------+-------| | EBB| O | gcc-12 | 1020.391 | +6% | |----+------------------+---------+------------------+-------| | EBB| X |clang-15 | 1160.894 | +19.4%| |----+------------------+---------+------------------+-------| | EBB| X | gcc-12 | 1167.938 | +21.2%|