diff options
| author | Christophe Leroy <[email protected]> | 2021-09-21 17:09:48 +0200 |
|---|---|---|
| committer | Michael Ellerman <[email protected]> | 2021-11-30 11:45:57 +1100 |
| commit | 41d65207de9fbff58acd8937a7c3f8940c186a87 (patch) | |
| tree | 26ecaba917e5a2af4390ba7ae07feab1a1233586 /tools/perf/scripts/python/event_analyzing_sample.py | |
| parent | fb350784d8d17952afa93383bb47aaa6b715c459 (diff) | |
powerpc/atomics: Use immediate operand when possible
Today we get the following code generation for atomic operations:
c001bb2c: 39 20 00 01 li r9,1
c001bb30: 7d 40 18 28 lwarx r10,0,r3
c001bb34: 7d 09 50 50 subf r8,r9,r10
c001bb38: 7d 00 19 2d stwcx. r8,0,r3
c001c7a8: 39 40 00 01 li r10,1
c001c7ac: 7d 00 18 28 lwarx r8,0,r3
c001c7b0: 7c ea 42 14 add r7,r10,r8
c001c7b4: 7c e0 19 2d stwcx. r7,0,r3
By allowing GCC to choose between immediate or regular operation,
we get:
c001bb2c: 7d 20 18 28 lwarx r9,0,r3
c001bb30: 39 49 ff ff addi r10,r9,-1
c001bb34: 7d 40 19 2d stwcx. r10,0,r3
--
c001c7a4: 7d 40 18 28 lwarx r10,0,r3
c001c7a8: 39 0a 00 01 addi r8,r10,1
c001c7ac: 7d 00 19 2d stwcx. r8,0,r3
For "and", the dot form has to be used because "andi" doesn't exist.
For logical operations we use unsigned 16 bits immediate.
For arithmetic operations we use signed 16 bits immediate.
On pmac32_defconfig, it reduces the text by approx another 8 kbytes.
Signed-off-by: Christophe Leroy <[email protected]>
Acked-by: Segher Boessenkool <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/2ec558d44db8045752fe9dbd29c9ba84bab6030b.1632236981.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'tools/perf/scripts/python/event_analyzing_sample.py')
0 files changed, 0 insertions, 0 deletions