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libgcc CRIS: Define TARGET_HAS_NO_HW_DIVIDE

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With this, execution time for e.g. __moddi3 go from 59 to 40 cycles in
the "fast" case or from 290 to 200 cycles in the "slow" case (when the
!TARGET_HAS_NO_HW_DIVIDE variant calls division and modulus functions
for 32-bit SImode), as exposed by gcc.c-torture/execute/arith-rand-ll.c
compiled for -march=v10.

Unfortunately, it just puts a performance improvement "dent" of 0.07%
in a arith-rand-ll.c-based performance test - where all loops are also
reduced to 1/10.

The size of every affected libgcc function is reduced to less than
half and they are all now leaf functions.

	* config/cris/t-cris (HOST_LIBGCC2_CFLAGS): Add
	-DTARGET_HAS_NO_HW_DIVIDE.
This commit is contained in:
Hans-Peter Nilsson 2023-04-27 02:00:33 +02:00 committed by Hans-Peter Nilsson
parent 2a26872984
commit d7f0bc0594
1 changed files with 3 additions and 0 deletions
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3
libgcc/config/cris/t-cris
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@ -8,3 +8,6 @@ $(LIB2ADD): $(srcdir)/config/cris/arit.c
echo "#define L$$name" > tmp-$@ \
&& echo '#include "$<"' >> tmp-$@ \
&& mv -f tmp-$@ $@
# Use an appropriate implementation when implementing DImode division.
HOST_LIBGCC2_CFLAGS += -DTARGET_HAS_NO_HW_DIVIDE