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qemu/bitops.h: Limit rotate amounts
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Rotates have been fixed up to only allow for reasonable rotate amounts
(ie, no rotates >7 on an 8b value etc.)  This fixes a problem with riscv
vector rotate instructions.

Signed-off-by: Dickon Hood <dickon.hood@codethink.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230428144757.57530-9-lawrence.hunter@codethink.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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dickonthree authored and rth7680 committed May 1, 2023
1 parent 5827422 commit 25cb258
Showing 1 changed file with 16 additions and 8 deletions.
24 changes: 16 additions & 8 deletions include/qemu/bitops.h
Original file line number Diff line number Diff line change
Expand Up @@ -218,7 +218,8 @@ static inline unsigned long find_first_zero_bit(const unsigned long *addr,
*/
static inline uint8_t rol8(uint8_t word, unsigned int shift)
{
return (word << shift) | (word >> ((8 - shift) & 7));
shift &= 7;
return (word << shift) | (word >> (8 - shift));
}

/**
Expand All @@ -228,7 +229,8 @@ static inline uint8_t rol8(uint8_t word, unsigned int shift)
*/
static inline uint8_t ror8(uint8_t word, unsigned int shift)
{
return (word >> shift) | (word << ((8 - shift) & 7));
shift &= 7;
return (word >> shift) | (word << (8 - shift));
}

/**
Expand All @@ -238,7 +240,8 @@ static inline uint8_t ror8(uint8_t word, unsigned int shift)
*/
static inline uint16_t rol16(uint16_t word, unsigned int shift)
{
return (word << shift) | (word >> ((16 - shift) & 15));
shift &= 15;
return (word << shift) | (word >> (16 - shift));
}

/**
Expand All @@ -248,7 +251,8 @@ static inline uint16_t rol16(uint16_t word, unsigned int shift)
*/
static inline uint16_t ror16(uint16_t word, unsigned int shift)
{
return (word >> shift) | (word << ((16 - shift) & 15));
shift &= 15;
return (word >> shift) | (word << (16 - shift));
}

/**
Expand All @@ -258,7 +262,8 @@ static inline uint16_t ror16(uint16_t word, unsigned int shift)
*/
static inline uint32_t rol32(uint32_t word, unsigned int shift)
{
return (word << shift) | (word >> ((32 - shift) & 31));
shift &= 31;
return (word << shift) | (word >> (32 - shift));
}

/**
Expand All @@ -268,7 +273,8 @@ static inline uint32_t rol32(uint32_t word, unsigned int shift)
*/
static inline uint32_t ror32(uint32_t word, unsigned int shift)
{
return (word >> shift) | (word << ((32 - shift) & 31));
shift &= 31;
return (word >> shift) | (word << (32 - shift));
}

/**
Expand All @@ -278,7 +284,8 @@ static inline uint32_t ror32(uint32_t word, unsigned int shift)
*/
static inline uint64_t rol64(uint64_t word, unsigned int shift)
{
return (word << shift) | (word >> ((64 - shift) & 63));
shift &= 63;
return (word << shift) | (word >> (64 - shift));
}

/**
Expand All @@ -288,7 +295,8 @@ static inline uint64_t rol64(uint64_t word, unsigned int shift)
*/
static inline uint64_t ror64(uint64_t word, unsigned int shift)
{
return (word >> shift) | (word << ((64 - shift) & 63));
shift &= 63;
return (word >> shift) | (word << (64 - shift));
}

/**
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