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author | Mans Rullgard <mans@mansr.com> | 2011-05-31 21:04:01 +0100 |
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committer | Mans Rullgard <mans@mansr.com> | 2011-05-31 22:21:00 +0100 |
commit | c51695dbf6e05b397ad8ef8e89d27723db5cb9f1 (patch) | |
tree | f5b35ff28446f2f4b39723bc6e4466f186ee666c /libavcodec/arm | |
parent | 5ac4952a5808cc8cfe01031ca9d4df7d072f453c (diff) | |
download | ffmpeg-streaming-c51695dbf6e05b397ad8ef8e89d27723db5cb9f1.zip ffmpeg-streaming-c51695dbf6e05b397ad8ef8e89d27723db5cb9f1.tar.gz |
ARM: fix MUL64 inline asm for pre-armv6
Prior to ARMv6, the destination registers of the SMULL instruction
must be distinct from the first source register. Marking the
output early-clobber ensures it is allocated unique registers.
This restriction is dropped in ARMv6 and later, so allowing overlap
between input and output registers there might give better code.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Diffstat (limited to 'libavcodec/arm')
-rw-r--r-- | libavcodec/arm/mathops.h | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/libavcodec/arm/mathops.h b/libavcodec/arm/mathops.h index dfa9411..7c2acca 100644 --- a/libavcodec/arm/mathops.h +++ b/libavcodec/arm/mathops.h @@ -41,6 +41,8 @@ static inline av_const int MULL(int a, int b, unsigned shift) } #define MULH MULH +#define MUL64 MUL64 + #if HAVE_ARMV6 static inline av_const int MULH(int a, int b) { @@ -48,6 +50,13 @@ static inline av_const int MULH(int a, int b) __asm__ ("smmul %0, %1, %2" : "=r"(r) : "r"(a), "r"(b)); return r; } + +static inline av_const int64_t MUL64(int a, int b) +{ + int64_t x; + __asm__ ("smull %Q0, %R0, %1, %2" : "=r"(x) : "r"(a), "r"(b)); + return x; +} #else static inline av_const int MULH(int a, int b) { @@ -55,15 +64,14 @@ static inline av_const int MULH(int a, int b) __asm__ ("smull %0, %1, %2, %3" : "=&r"(lo), "=&r"(hi) : "r"(b), "r"(a)); return hi; } -#endif static inline av_const int64_t MUL64(int a, int b) { int64_t x; - __asm__ ("smull %Q0, %R0, %1, %2" : "=r"(x) : "r"(a), "r"(b)); + __asm__ ("smull %Q0, %R0, %1, %2" : "=&r"(x) : "r"(a), "r"(b)); return x; } -#define MUL64 MUL64 +#endif static inline av_const int64_t MAC64(int64_t d, int a, int b) { |