nouveau: add result scaling to shader backend, use it in RSQ emul for NV40.

src/mesa/drivers/dri/nouveau/nouveau_shader.c

@@ -179,7 +179,7 @@ nvsBuildTextShader(GLcontext *ctx, GLenum target, const char *text)
 				     strlen(text),
 				     &nvs->mesa.vp);
    } else if (target == GL_FRAGMENT_PROGRAM_ARB) {
-      _mesa_init_fragment_program(ctx, &nvs->mesa.fp, GL_VERTEX_PROGRAM_ARB, 0);
+      _mesa_init_fragment_program(ctx, &nvs->mesa.fp, GL_FRAGMENT_PROGRAM_ARB, 0);
       _mesa_parse_arb_fragment_program(ctx,
 	    			       GL_FRAGMENT_PROGRAM_ARB,
 				       text,

src/mesa/drivers/dri/nouveau/nouveau_shader.h

@@ -194,6 +194,16 @@ typedef enum {
    NVS_TEX_TARGET_UNKNOWN = 0
 } nvsTexTarget;
 
+typedef enum {
+	NVS_SCALE_1X	 = 0,
+	NVS_SCALE_2X	 = 1,
+	NVS_SCALE_4X	 = 2,
+	NVS_SCALE_8X	 = 3,
+	NVS_SCALE_INV_2X = 5,
+	NVS_SCALE_INV_4X = 6,
+	NVS_SCALE_INV_8X = 7,
+} nvsScale;
+
 /* Arith/TEX instructions */
 typedef struct nvs_instruction {
    nvsFragmentHeader header;
@@ -203,6 +213,7 @@ typedef struct nvs_instruction {
 
    nvsRegister	dest;
    unsigned int	mask;
+   nvsScale	dest_scale;
 
    nvsRegister	src[3];
 
@@ -307,6 +318,7 @@ struct _nvsFunc {
 
    void		(*InitInstruction)	(nvsFunc *);
    int		(*SupportsOpcode)	(nvsFunc *, nvsOpcode);
+   int		(*SupportsResultScale)	(nvsFunc *, nvsScale);
    void		(*SetOpcode)		(nvsFunc *, unsigned int opcode,
 	 				 int slot);
    void		(*SetCCUpdate)		(nvsFunc *);
@@ -314,6 +326,7 @@ struct _nvsFunc {
 	 				 nvsSwzComp *swizzle);
    void		(*SetResult)		(nvsFunc *, nvsRegister *,
 	 				 unsigned int mask, int slot);
+   void		(*SetResultScale)	(nvsFunc *, nvsScale);
    void		(*SetSource)		(nvsFunc *, nvsRegister *, int pos);
    void		(*SetTexImageUnit)	(nvsFunc *, int unit);
    void		(*SetSaturate)		(nvsFunc *);

src/mesa/drivers/dri/nouveau/nouveau_shader_0.c

@@ -402,6 +402,7 @@ pass0_emit(nouveauShader *nvs, nvsFragmentHeader *parent, int fpos,
 	sif->saturate	= saturate;
 	sif->dest	= dst;
 	sif->mask	= mask;
+	sif->dest_scale	= NVS_SCALE_1X;
 	sif->src[0]	= src0;
 	sif->src[1]	= src1;
 	sif->src[2]	= src2;
@@ -667,25 +668,13 @@ pass0_emulate_instruction(nouveauShader *nvs,
 		}
 		break;
 	case OPCODE_RSQ:
-		if (rec->const_half.file != NVS_FILE_CONST) {
-			GLfloat const_half[4] = { 0.5, 0.0, 0.0, 0.0 };
-			pass0_make_reg(nvs, &rec->const_half, NVS_FILE_CONST,
-					_mesa_add_unnamed_constant(
-						nvs->mesa.vp.Base.Parameters,
-						const_half, 4));
-			COPY_4V(nvs->params[rec->const_half.index].val,
-				const_half);
-		}
 		pass0_make_reg(nvs, &temp, NVS_FILE_TEMP, -1);
 		ARITHu(NVS_OP_LG2, temp, SMASK_X, 0,
 				 nvsAbs(nvsSwizzle(src[0], X, X, X, X)),
 				 nvr_unused, nvr_unused);
-		ARITHu(NVS_OP_MUL, temp, SMASK_X, 0,
-				 nvsSwizzle(temp, X, X, X, X),
-				 nvsNegate(rec->const_half),
-				 nvr_unused);
+		nvsinst->dest_scale = NVS_SCALE_INV_2X;
 		ARITH (NVS_OP_EX2, dest, mask, sat,
-				 nvsSwizzle(temp, X, X, X, X),
+				 nvsNegate(nvsSwizzle(temp, X, X, X, X)),
 				 nvr_unused, nvr_unused);
 		break;
 	case OPCODE_SCS:

src/mesa/drivers/dri/nouveau/nouveau_shader_2.c

@@ -135,6 +135,10 @@ pass2_add_instruction(nvsPtr nvs, nvsInstruction *inst,
 
 	reg = pass2_mangle_reg(nvs, inst, inst->dest);
 	shader->SetResult(shader, &reg, inst->mask, slot);
+
+	if (inst->dest_scale != NVS_SCALE_1X) {
+		shader->SetResultScale(shader, inst->dest_scale);
+	}
 }
 
 static int

src/mesa/drivers/dri/nouveau/nv40_fragprog.c

@@ -11,6 +11,30 @@ struct _op_xlat NVFP_TX_BOP[64];
  * 	- These extend the NV30 routines, which are almost identical.  NV40
  * 	  just has branching hacked into the instruction set.
  */
+static int
+NV40FPSupportsResultScale(nvsFunc *shader, nvsScale scale)
+{
+	switch (scale) {
+	case NVS_SCALE_1X:
+	case NVS_SCALE_2X:
+	case NVS_SCALE_4X:
+	case NVS_SCALE_8X:
+	case NVS_SCALE_INV_2X:
+	case NVS_SCALE_INV_4X:
+	case NVS_SCALE_INV_8X:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static void
+NV40FPSetResultScale(nvsFunc *shader, nvsScale scale)
+{
+	shader->inst[2] &= ~NV40_FP_OP_DST_SCALE_MASK;
+	shader->inst[2] |= ((unsigned int)scale << NV40_FP_OP_DST_SCALE_SHIFT);
+}
+
 static void
 NV40FPSetBranchTarget(nvsFunc *shader, int addr)
 {
@@ -179,6 +203,9 @@ NV40FPInitShaderFuncs(nvsFunc * shader)
    MOD_OPCODE(NVFP_TX_BOP, NV40_FP_OP_BRA_OPCODE_REP , NVS_OP_REP , -1, -1, -1);
    MOD_OPCODE(NVFP_TX_BOP, NV40_FP_OP_BRA_OPCODE_RET , NVS_OP_RET , -1, -1, -1);
 
+   shader->SupportsResultScale	= NV40FPSupportsResultScale;
+   shader->SetResultScale	= NV40FPSetResultScale;
+
    /* fragment.facing */
    shader->GetSourceID		= NV40FPGetSourceID;
 

src/mesa/drivers/dri/nouveau/nv40_shader.h

@@ -399,8 +399,8 @@
 
 /* high order bits of SRC1 */
 #define NV40_FP_OP_OPCODE_IS_BRANCH                                      (1<<31)
-#define NV40_FP_OP_SRC_SCALE_SHIFT                                            28
-#define NV40_FP_OP_SRC_SCALE_MASK                                      (3 << 28)
+#define NV40_FP_OP_DST_SCALE_SHIFT                                            28
+#define NV40_FP_OP_DST_SCALE_MASK                                      (3 << 28)
 
 /* SRC1 LOOP */
 #define NV40_FP_OP_LOOP_INCR_SHIFT                                            19