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| author | Wolfgang Hospital <Wolfgang.Hospital@arcor.de> | 2024-05-07 16:24:39 +0200 |
|---|---|---|
| committer | Georg-Johann Lay <avr@gjlay.de> | 2024-05-07 16:32:07 +0200 |
| commit | 8d2c93fcfe1afc5291bbbe162c3b7ad5764f6d8d (patch) | |
| tree | e40a2309a046c0a556a80a4c5a9bbfd4a787bf81 | |
| parent | 3f04f3939ea0ac8fdd766a60655d29de2ffb44e5 (diff) | |
| download | gcc-8d2c93fcfe1afc5291bbbe162c3b7ad5764f6d8d.zip gcc-8d2c93fcfe1afc5291bbbe162c3b7ad5764f6d8d.tar.gz gcc-8d2c93fcfe1afc5291bbbe162c3b7ad5764f6d8d.tar.bz2 | |
AVR: target/114835 - Tweak popcountqi2
libgcc/
PR target/114835
* config/avr/lib1funcs.S (__popcountqi2): Use code that
is one instruction shorter / faster.
| -rw-r--r-- | libgcc/config/avr/lib1funcs.S | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/libgcc/config/avr/lib1funcs.S b/libgcc/config/avr/lib1funcs.S index af4d7d9..4ac31fa 100644 --- a/libgcc/config/avr/lib1funcs.S +++ b/libgcc/config/avr/lib1funcs.S @@ -3050,21 +3050,21 @@ ENDF __popcountdi2 ;; r24 = popcount8 (r24) ;; clobbers: __tmp_reg__ DEFUN __popcountqi2 - mov __tmp_reg__, r24 - andi r24, 1 - lsr __tmp_reg__ - lsr __tmp_reg__ - adc r24, __zero_reg__ - lsr __tmp_reg__ - adc r24, __zero_reg__ - lsr __tmp_reg__ - adc r24, __zero_reg__ - lsr __tmp_reg__ - adc r24, __zero_reg__ - lsr __tmp_reg__ - adc r24, __zero_reg__ - lsr __tmp_reg__ - adc r24, __tmp_reg__ + mov __tmp_reg__, r24 ; oeoeoeoe + andi r24, 0xAA ; o0o0o0o0 + lsr r24 ; 0o0o0o0o + ;; Four values 0, 1 or 2: # bits set o+e + sub __tmp_reg__, r24 ; 44332211 + mov r24, __tmp_reg__ ; 44332211 + andi r24, 0x33 ; 00330011 + eor __tmp_reg__, r24 ; 44002200 + lsr __tmp_reg__ ; 04400220 + lsr __tmp_reg__ ; 00440022 + add r24, __tmp_reg__ ; 04210421 + mov __tmp_reg__, r24 ; h421l421 + swap __tmp_reg__ ; l421h421 + add r24, __tmp_reg__ ; 84218421 + andi r24, 0xf ; 00008421 /17 ret ENDF __popcountqi2 #endif /* defined (L_popcountqi2) */ |