diff options
Diffstat (limited to 'src/gallium/auxiliary/tgsi/exec/tgsi_sse2.c')
| -rwxr-xr-x | src/gallium/auxiliary/tgsi/exec/tgsi_sse2.c | 65 |
1 files changed, 26 insertions, 39 deletions
diff --git a/src/gallium/auxiliary/tgsi/exec/tgsi_sse2.c b/src/gallium/auxiliary/tgsi/exec/tgsi_sse2.c index 2fd76a3072..8018bd7fa4 100755 --- a/src/gallium/auxiliary/tgsi/exec/tgsi_sse2.c +++ b/src/gallium/auxiliary/tgsi/exec/tgsi_sse2.c @@ -36,7 +36,11 @@ #ifdef PIPE_ARCH_X86 -#define HIGH_PRECISION 1 /* for 1/sqrt() */ +/* for 1/sqrt() + * + * This costs about 100fps (close to 10%) in gears: + */ +#define HIGH_PRECISION 1 #define FOR_EACH_CHANNEL( CHAN )\ @@ -757,20 +761,6 @@ emit_rcp ( make_xmm( xmm_src ) ); } -#if HIGH_PRECISION -static void XSTDCALL -rsqrt4f( - float *store ) -{ - const unsigned X = 0; - - store[X + 0] = 1.0F / sqrtf( store[X + 0] ); - store[X + 1] = 1.0F / sqrtf( store[X + 1] ); - store[X + 2] = 1.0F / sqrtf( store[X + 2] ); - store[X + 3] = 1.0F / sqrtf( store[X + 3] ); -} -#endif - static void emit_rsqrt( struct x86_function *func, @@ -778,13 +768,6 @@ emit_rsqrt( unsigned xmm_src ) { #if HIGH_PRECISION -#if 1 - emit_func_call_dst_src( - func, - xmm_dst, - xmm_src, - rsqrt4f ); -#else /* Although rsqrtps() and rcpps() are low precision on some/all SSE * implementations, it is possible to improve its precision at * fairly low cost, using a newton/raphson step, as below: @@ -794,21 +777,25 @@ emit_rsqrt( * * See: http://softwarecommunity.intel.com/articles/eng/1818.htm */ - /* This is some code that woudl do the above for a scalar 'a'. We - * obviously are interested in a vector version: - * - * movss xmm3, a; - * movss xmm1, half; - * movss xmm2, three; - * rsqrtss xmm0, xmm3; - * mulss xmm3, xmm0; - * mulss xmm1, xmm0; - * mulss xmm3, xmm0; - * subss xmm2, xmm3; - * mulss xmm1, xmm2; - * movss x, xmm1; - */ -#endif + { + struct x86_reg dst = make_xmm( xmm_dst ); + struct x86_reg src = make_xmm( xmm_src ); + struct x86_reg tmp0 = make_xmm( 2 ); + struct x86_reg tmp1 = make_xmm( 3 ); + + assert( xmm_dst != xmm_src ); + assert( xmm_dst != 2 && xmm_dst != 3 ); + assert( xmm_src != 2 && xmm_src != 3 ); + + sse_movaps( func, dst, get_temp( TGSI_EXEC_TEMP_HALF_I, TGSI_EXEC_TEMP_HALF_C ) ); + sse_movaps( func, tmp0, get_temp( TGSI_EXEC_TEMP_THREE_I, TGSI_EXEC_TEMP_THREE_C ) ); + sse_rsqrtps( func, tmp1, src ); + sse_mulps( func, src, tmp1 ); + sse_mulps( func, dst, tmp1 ); + sse_mulps( func, src, tmp1 ); + sse_subps( func, tmp0, src ); + sse_mulps( func, dst, tmp0 ); + } #else /* On Intel CPUs at least, this is only accurate to 12 bits -- not * good enough. @@ -1295,9 +1282,9 @@ emit_instruction( case TGSI_OPCODE_RSQ: /* TGSI_OPCODE_RECIPSQRT */ FETCH( func, *inst, 0, 0, CHAN_X ); - emit_rsqrt( func, 0, 0 ); + emit_rsqrt( func, 1, 0 ); FOR_EACH_DST0_ENABLED_CHANNEL( *inst, chan_index ) { - STORE( func, *inst, 0, 0, chan_index ); + STORE( func, *inst, 1, 0, chan_index ); } break; |