forked from minhngoc25a/freetype2
Add assembler code for TT_MulFix14 and TT_DotFix14.
This patch provides slightly optimized versions for ARM, x86, and x86_64 CPUs if built with GCC. Also remove some dead code. * src/truetype/ttinterp.c (TT_MulFix14_arm, TT_MulFix14_long_long, TT_DotFix14_long_long): New functions.
This commit is contained in:
David Turner
Werner Lemberg
parent
b28908860d
commit
f66d48e923
12
ChangeLog
12
ChangeLog
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@ -1,3 +1,15 @@
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2013-07-16 David Turner <digit@google.com>
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[truetype] Add assembler code for TT_MulFix14 and TT_DotFix14.
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This patch provides slightly optimized versions for ARM, x86, and
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x86_64 CPUs if built with GCC.
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Also remove some dead code.
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* src/truetype/ttinterp.c (TT_MulFix14_arm, TT_MulFix14_long_long,
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TT_DotFix14_long_long): New functions.
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2013-07-16 David Turner <digit@google.com>
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Optimize FT_MulFix for x86_64 GCC builds.
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@ -1437,8 +1437,99 @@
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#undef PACK
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#if 1
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#ifndef FT_CONFIG_OPTION_NO_ASSEMBLER
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#if defined( __arm__ ) && \
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( defined( __thumb2__ ) || !defined( __thumb__ ) )
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#define TT_MulFix14 TT_MulFix14_arm
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static FT_Int32
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TT_MulFix14_arm( FT_Int32 a,
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FT_Int b )
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{
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register FT_Int32 t, t2;
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#if defined( __CC_ARM ) || defined( __ARMCC__ )
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__asm
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{
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smull t2, t, b, a /* (lo=t2,hi=t) = a*b */
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mov a, t, asr #31 /* a = (hi >> 31) */
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add a, a, #0x2000 /* a += 0x2000 */
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adds t2, t2, a /* t2 += a */
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adc t, t, #0 /* t += carry */
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mov a, t2, lsr #14 /* a = t2 >> 14 */
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orr a, a, t, lsl #18 /* a |= t << 18 */
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}
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#elif defined( __GNUC__ )
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__asm__ __volatile__ (
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"smull %1, %2, %4, %3\n\t" /* (lo=%1,hi=%2) = a*b */
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"mov %0, %2, asr #31\n\t" /* %0 = (hi >> 31) */
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"add %0, %0, #0x2000\n\t" /* %0 += 0x2000 */
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"adds %1, %1, %0\n\t" /* %1 += %0 */
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"adc %2, %2, #0\n\t" /* %2 += carry */
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"mov %0, %1, lsr #14\n\t" /* %0 = %1 >> 16 */
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"orr %0, %0, %2, lsl #18\n\t" /* %0 |= %2 << 16 */
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: "=r"(a), "=&r"(t2), "=&r"(t)
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: "r"(a), "r"(b)
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: "cc" );
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#endif
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return a;
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}
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#endif /* __arm__ && ( __thumb2__ || !__thumb__ ) */
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#endif /* !FT_CONFIG_OPTION_NO_ASSEMBLER */
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#if defined( __GNUC__ ) && \
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( defined( __i386__ ) || defined( __x86_64__ ) )
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#define TT_MulFix14 TT_MulFix14_long_long
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/* This is declared `noinline' because inlining the function results */
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/* in slower code. The `pure' attribute indicates that the result */
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/* only depends on the parameters. */
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static __attribute__(( noinline ))
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__attribute__(( pure )) FT_Int32
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TT_MulFix14_long_long( FT_Int32 a,
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FT_Int b )
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{
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/* Temporarily disable the warning that C90 doesn't support */
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/* `long long'. */
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#pragma GCC diagnostic push
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#pragma GCC diagnostic ignored "-Wlong-long"
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long long ret = (long long)a * b;
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/* The following line assumes that right shifting of signed values */
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/* will actually preserve the sign bit. The exact behaviour is */
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/* undefined, but this is true on x86 and x86_64. */
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long long tmp = ret >> 63;
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ret += 0x2000 + tmp;
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return (FT_Int32)( ret >> 14 );
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#pragma GCC diagnostic pop
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}
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#endif /* __GNUC__ && ( __i386__ || __x86_64__ ) */
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#ifndef TT_MulFix14
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/* Compute (a*b)/2^14 with maximum accuracy and rounding. */
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/* This is optimized to be faster than calling FT_MulFix() */
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/* for platforms where sizeof(int) == 2. */
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static FT_Int32
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TT_MulFix14( FT_Int32 a,
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FT_Int b )
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@ -1470,37 +1561,44 @@
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return sign >= 0 ? (FT_Int32)mid : -(FT_Int32)mid;
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}
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#else
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#endif /* !TT_MulFix14 */
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/* compute (a*b)/2^14 with maximum accuracy and rounding */
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static FT_Int32
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TT_MulFix14( FT_Int32 a,
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FT_Int b )
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#if defined( __GNUC__ ) && \
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( defined( __i386__ ) || \
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defined( __x86_64__ ) || \
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defined( __arm__ ) )
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#define TT_DotFix14 TT_DotFix14_long_long
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static __attribute__(( pure )) FT_Int32
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TT_DotFix14_long_long( FT_Int32 ax,
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FT_Int32 ay,
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FT_Int bx,
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FT_Int by )
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{
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FT_Int32 m, s, hi;
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FT_UInt32 l, lo;
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/* Temporarily disable the warning that C90 doesn't support */
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/* `long long'. */
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#pragma GCC diagnostic push
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#pragma GCC diagnostic ignored "-Wlong-long"
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long long temp1 = (long long)ax * bx;
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long long temp2 = (long long)ay * by;
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/* compute ax*bx as 64-bit value */
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l = (FT_UInt32)( ( a & 0xFFFFU ) * b );
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m = ( a >> 16 ) * b;
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temp1 += temp2;
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temp2 = temp1 >> 63;
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temp1 += 0x2000 + temp2;
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lo = l + ( (FT_UInt32)m << 16 );
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hi = ( m >> 16 ) + ( (FT_Int32)l >> 31 ) + ( lo < l );
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return (FT_Int32)( temp1 >> 14 );
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/* divide the result by 2^14 with rounding */
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s = hi >> 31;
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l = lo + (FT_UInt32)s;
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hi += s + ( l < lo );
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lo = l;
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l = lo + 0x2000U;
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hi += l < lo;
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return (FT_Int32)( ( (FT_UInt32)hi << 18 ) | ( l >> 14 ) );
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#pragma GCC diagnostic pop
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}
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#endif
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#endif /* __GNUC__ && (__arm__ || __i386__ || __x86_64__) */
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#ifndef TT_DotFix14
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/* compute (ax*bx+ay*by)/2^14 with maximum accuracy and rounding */
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static FT_Int32
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@ -1543,6 +1641,8 @@
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return (FT_Int32)( ( (FT_UInt32)hi << 18 ) | ( l >> 14 ) );
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}
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#endif /* TT_DotFix14 */
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/*************************************************************************/
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/* */
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