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| author | Takayuki 'January June' Suwa <jjsuwa_sys3175@yahoo.co.jp> | 2022-07-22 20:15:50 +0900 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2022-07-22 12:25:38 -0700 |
| commit | 64cb87b2381aceaa37230bae7f43c7b9f978d3e3 (patch) | |
| tree | cecb4747879ad3afa80f418cee67b3c3738da96c /gcc/value-range.h | |
| parent | cf1725610526fe347d2530455b32affc033fd7fc (diff) | |
| download | gcc-64cb87b2381aceaa37230bae7f43c7b9f978d3e3.zip gcc-64cb87b2381aceaa37230bae7f43c7b9f978d3e3.tar.gz gcc-64cb87b2381aceaa37230bae7f43c7b9f978d3e3.tar.bz2 | |
xtensa: Optimize "bitwise AND NOT with imm" followed by "branch if (not) equal to zero"
The RTL combiner will transform "if ((x & C) == C) goto label;"
into "if ((~x & C) == 0) goto label;" and will try to match it with
the insn patterns.
/* example */
void test_0(int a) {
if ((char)a == 255)
foo();
}
void test_1(int a) {
if ((unsigned short)a == 0xFFFF)
foo();
}
void test_2(int a) {
if ((a & 0x00003F80) != 0x00003F80)
foo();
}
;; before
test_0:
extui a2, a2, 0, 8
movi a3, 0xff
bne a2, a3, .L1
j.l foo, a9
.L1:
ret.n
test_1:
movi.n a3, -1
extui a2, a2, 0, 16
extui a3, a3, 16, 16
bne a2, a3, .L3
j.l foo, a9
.L3:
ret.n
test_2:
movi a3, 0x80
extui a2, a2, 7, 7
addmi a3, a3, 0x3f00
slli a2, a2, 7
beq a2, a3, .L5
j.l foo, a9
.L5:
ret.n
;; after
test_0:
movi a3, 0xff
bnall a2, a3, .L1
j.l foo, a9
.L1:
ret.n
test_1:
movi.n a3, -1
extui a3, a3, 16, 16
bnall a2, a3, .L3
j.l foo, a9
.L3:
ret.n
test_2:
movi a3, 0x80
addmi a3, a3, 0x3f00
ball a2, a3, .L5
j.l foo, a9
.L5:
ret.n
gcc/ChangeLog:
* config/xtensa/xtensa.md (*masktrue_const_bitcmpl):
Add a new insn_and_split pattern, and a few split patterns for
spacial cases.
Diffstat (limited to 'gcc/value-range.h')
0 files changed, 0 insertions, 0 deletions