From 8d2c93fcfe1afc5291bbbe162c3b7ad5764f6d8d Mon Sep 17 00:00:00 2001 From: Wolfgang Hospital Date: Tue, 7 May 2024 16:24:39 +0200 Subject: [PATCH] AVR: target/114835 - Tweak popcountqi2 libgcc/ PR target/114835 * config/avr/lib1funcs.S (__popcountqi2): Use code that is one instruction shorter / faster. --- libgcc/config/avr/lib1funcs.S | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/libgcc/config/avr/lib1funcs.S b/libgcc/config/avr/lib1funcs.S index af4d7d97016..4ac31fa104e 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) */