From 351eca365c0ba488000c3826d5093de6170381e4 Mon Sep 17 00:00:00 2001 From: Keith Whitwell Date: Mon, 26 May 2008 11:03:00 +0100 Subject: [PATCH] draw: extend precision in RSQ opcode --- src/gallium/auxiliary/draw/draw_vs_aos.c | 48 +++++++++++++----------- src/gallium/auxiliary/draw/draw_vs_aos.h | 1 + 2 files changed, 28 insertions(+), 21 deletions(-) diff --git a/src/gallium/auxiliary/draw/draw_vs_aos.c b/src/gallium/auxiliary/draw/draw_vs_aos.c index 916203c66b8..1622358ae1f 100644 --- a/src/gallium/auxiliary/draw/draw_vs_aos.c +++ b/src/gallium/auxiliary/draw/draw_vs_aos.c @@ -140,7 +140,8 @@ static void init_internals( struct aos_machine *machine ) ASSIGN_4V(machine->internal[IMM_NEGS], -1.0f, -1.0f, -1.0f, -1.0f); ASSIGN_4V(machine->internal[IMM_IDENTITY], 0.0f, 0.0f, 0.0f, 1.0f); ASSIGN_4V(machine->internal[IMM_INV_255], inv, inv, inv, inv); - ASSIGN_4V(machine->internal[IMM_255], f255, f255, f255, f255); + ASSIGN_4V(machine->internal[IMM_255], f255, f255, f255, f255); + ASSIGN_4V(machine->internal[IMM_RSQ], -.5f, 1.5f, 0.0f, 0.0f); machine->fpu_rnd_nearest = (X87_CW_EXCEPTION_INV_OP | @@ -1561,35 +1562,40 @@ static boolean emit_RCP( struct aos_compilation *cp, const struct tgsi_full_inst * * x1 = 2 * rcpps(a) - a * rcpps(a) * rcpps(a) * x1 = 0.5 * rsqrtps(a) * [3.0 - (a * rsqrtps(a))* rsqrtps(a)] + * or: + * x1 = rsqrtps(a) * [1.5 - .5 * a * rsqrtps(a) * rsqrtps(a)] + * * * See: http://softwarecommunity.intel.com/articles/eng/1818.htm */ static boolean emit_RSQ( struct aos_compilation *cp, const struct tgsi_full_instruction *op ) { - struct x86_reg arg0 = fetch_src(cp, &op->FullSrcRegisters[0]); - struct x86_reg dst = aos_get_xmm_reg(cp); - if (1) { - sse_rsqrtss(cp->func, dst, arg0); + if (0) { + struct x86_reg arg0 = fetch_src(cp, &op->FullSrcRegisters[0]); + struct x86_reg r = aos_get_xmm_reg(cp); + sse_rsqrtss(cp->func, r, arg0); + store_scalar_dest(cp, &op->FullDstRegisters[0], r); + return TRUE; } else { -#if 0 - /* Extend precision here... - */ - 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_rsqrtss( func, tmp1, src ); /* rsqrtss(a) */ - sse_mulss( func, src, tmp1 ); /* a * rsqrtss(a) */ - sse_mulss( func, dst, tmp1 ); /* .5 * rsqrtss(a) */ - sse_mulss( func, src, tmp1 ); /* a * rsqrtss(a) * rsqrtss(a) */ - sse_subss( func, tmp0, src ); /* 3.0 - (a * rsqrtss(a) * rsqrtss(a)) */ - sse_mulss( func, dst, tmp0 ); /* .5 * r * (3.0 - (a * r * r)) */ -#endif - } + struct x86_reg arg0 = fetch_src(cp, &op->FullSrcRegisters[0]); + struct x86_reg r = aos_get_xmm_reg(cp); - store_scalar_dest(cp, &op->FullDstRegisters[0], dst); - return TRUE; + struct x86_reg neg_half = get_reg_ptr( cp, AOS_FILE_INTERNAL, IMM_RSQ ); + struct x86_reg one_point_five = x86_make_disp( neg_half, 4 ); + struct x86_reg src = get_xmm_writable( cp, arg0 ); + + sse_rsqrtss( cp->func, r, src ); /* rsqrtss(a) */ + sse_mulss( cp->func, src, neg_half ); /* -.5 * a */ + sse_mulss( cp->func, src, r ); /* -.5 * a * r */ + sse_mulss( cp->func, src, r ); /* -.5 * a * r * r */ + sse_addss( cp->func, src, one_point_five ); /* 1.5 - .5 * a * r * r */ + sse_mulss( cp->func, r, src ); /* r * (1.5 - .5 * a * r * r) */ + + store_scalar_dest(cp, &op->FullDstRegisters[0], r); + return TRUE; + } } diff --git a/src/gallium/auxiliary/draw/draw_vs_aos.h b/src/gallium/auxiliary/draw/draw_vs_aos.h index c08c73d4bc0..fffe2e4658c 100644 --- a/src/gallium/auxiliary/draw/draw_vs_aos.h +++ b/src/gallium/auxiliary/draw/draw_vs_aos.h @@ -175,6 +175,7 @@ boolean aos_emit_outputs( struct aos_compilation *cp ); #define IMM_INV_255 3 /* 1/255, 1/255, 1/255, 1/255 */ #define IMM_255 4 /* 255, 255, 255, 255 */ #define IMM_NEGS 5 /* -1,-1,-1,-1 */ +#define IMM_RSQ 6 /* -.5,1.5,_,_ */ struct x86_reg aos_get_internal( struct aos_compilation *cp, unsigned imm ); -- 2.30.2