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MIPS: bitops: Allow immediates in test_and_{set,clear,change}_bit 

The logical operations or & xor used in the test_and_set_bit_lock(),
test_and_clear_bit() & test_and_change_bit() functions currently force
the value 1<<bit to be placed in a register. If the bit is compile-time
constant & fits within the immediate field of an or/xor instruction (ie.
16 bits) then we can make use of the ori/xori instruction variants &
avoid the use of an extra register. Add the extra "i" constraints in
order to allow use of these immediate encodings.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-kernel@vger.kernel.org
This commit is contained in:
Paul Burton 2019-10-01 21:53:31 +00:00
parent 6bbe043bd3
commit a2e66b862c
No known key found for this signature in database
GPG Key ID: 3EA79FACB57500DD
1 changed files with 6 additions and 6 deletions
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12
arch/mips/include/asm/bitops.h
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@ -261,7 +261,7 @@ static inline int test_and_set_bit_lock(unsigned long nr,
" and %2, %0, %3 \n"
" .set pop \n"
: "=&r" (temp), "+m" (*m), "=&r" (res)
: "r" (1UL << bit)
: "ir" (1UL << bit)
: __LLSC_CLOBBER);
} else {
loongson_llsc_mb();
@ -274,7 +274,7 @@ static inline int test_and_set_bit_lock(unsigned long nr,
" " __SC "%2, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "r" (1UL << bit)
: "ir" (1UL << bit)
: __LLSC_CLOBBER);
} while (unlikely(!res));
@ -332,7 +332,7 @@ static inline int test_and_clear_bit(unsigned long nr,
" and %2, %0, %3 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "r" (1UL << bit)
: "ir" (1UL << bit)
: __LLSC_CLOBBER);
} else if ((MIPS_ISA_REV >= 2) && __builtin_constant_p(nr)) {
loongson_llsc_mb();
@ -358,7 +358,7 @@ static inline int test_and_clear_bit(unsigned long nr,
" " __SC "%2, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "r" (1UL << bit)
: "ir" (1UL << bit)
: __LLSC_CLOBBER);
} while (unlikely(!res));
@ -400,7 +400,7 @@ static inline int test_and_change_bit(unsigned long nr,
" and %2, %0, %3 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "r" (1UL << bit)
: "ir" (1UL << bit)
: __LLSC_CLOBBER);
} else {
loongson_llsc_mb();
@ -413,7 +413,7 @@ static inline int test_and_change_bit(unsigned long nr,
" " __SC "\t%2, %1 \n"
" .set pop \n"
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (*m), "=&r" (res)
: "r" (1UL << bit)
: "ir" (1UL << bit)
: __LLSC_CLOBBER);
} while (unlikely(!res));