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AVR: Speed up __umulhisi3 for small devices with MUL.

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__umulhisi3 had an "rcall 1f" to save 6 bytes, which is an unreasonable
size gain vs. cycle cost.  Just use the same code on all devices with MUL,
irrespective of program memory size.

libgcc/
	* config/avr/lib1funcs.S (__umulhisi3) [Have MUL]: Reduce call
	depth by 1.
This commit is contained in:
Georg-Johann Lay 2025-04-04 22:01:43 +02:00
parent 7d56182052
commit 6753df43a0
1 changed files with 1 additions and 8 deletions
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9
libgcc/config/avr/lib1funcs.S
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@ -581,19 +581,12 @@ DEFUN __umulhisi3
mul A1, B1
movw C2, r0
mul A0, B1
#ifdef __AVR_HAVE_JMP_CALL__
;; This function is used by many other routines, often multiple times.
;; Therefore, if the flash size is not too limited, avoid the RCALL
;; and inverst 6 Bytes to speed things up.
add C1, r0
adc C2, r1
clr __zero_reg__
adc C3, __zero_reg__
#else
rcall 1f
#endif
mul A1, B0
1: add C1, r0
add C1, r0
adc C2, r1
clr __zero_reg__
adc C3, __zero_reg__