[Mesa-dev] [PATCH] r600: fix texture gradients instruction emission (v2)

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

The piglit tests were failing, and it appeared to be SB
optimising out things, but Glenn pointed out the gradients
are meant to be clause local, so we should emit the texture
instructions in the same clause. This moves things around
to always copy to a temp and then emit the texture clauses
for H/V.

v2: Glenn pointed out we could get another ALU fetch in
the wrong place, so load the src gpr earlier as well.

Fixes at least:
./bin/tex-miplevel-selection textureGrad 2D

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 src/gallium/drivers/r600/r600_shader.c | 59 ++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 28 deletions(-)

diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index 76daf2c..41caac3 100644
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -5110,11 +5110,37 @@ static int tgsi_tex(struct r600_shader_ctx *ctx)
 	}
 
 	if (inst->Instruction.Opcode == TGSI_OPCODE_TXD) {
+		int temp_h, temp_v;
 		/* TGSI moves the sampler to src reg 3 for TXD */
 		sampler_src_reg = 3;
 
 		sampler_index_mode = inst->Src[sampler_src_reg].Indirect.Index == 2 ? 2 : 0; // CF_INDEX_1 : CF_INDEX_NONE
 
+		src_loaded = TRUE;
+		for (i = 0; i < 3; i++) {
+			int treg = r600_get_temp(ctx);
+
+			if (i == 0)
+				src_gpr = treg;
+			else if (i == 1)
+				temp_h = treg;
+			else
+				temp_v = treg;
+
+			for (j = 0; j < 4; j++) {
+				memset(&alu, 0, sizeof(struct r600_bytecode_alu));
+				alu.op = ALU_OP1_MOV;
+                                r600_bytecode_src(&alu.src[0], &ctx->src[i], j);
+                                alu.dst.sel = treg;
+                                alu.dst.chan = j;
+                                if (j == 3)
+                                   alu.last = 1;
+                                alu.dst.write = 1;
+                                r = r600_bytecode_add_alu(ctx->bc, &alu);
+                                if (r)
+                                    return r;
+			}
+		}
 		for (i = 1; i < 3; i++) {
 			/* set gradients h/v */
 			memset(&tex, 0, sizeof(struct r600_bytecode_tex));
@@ -5125,35 +5151,12 @@ static int tgsi_tex(struct r600_shader_ctx *ctx)
 			tex.resource_id = tex.sampler_id + R600_MAX_CONST_BUFFERS;
 			tex.resource_index_mode = sampler_index_mode;
 
-			if (tgsi_tex_src_requires_loading(ctx, i)) {
-				tex.src_gpr = r600_get_temp(ctx);
-				tex.src_sel_x = 0;
-				tex.src_sel_y = 1;
-				tex.src_sel_z = 2;
-				tex.src_sel_w = 3;
+			tex.src_gpr = (i == 1) ? temp_h : temp_v;
+			tex.src_sel_x = 0;
+			tex.src_sel_y = 1;
+			tex.src_sel_z = 2;
+			tex.src_sel_w = 3;
 
-				for (j = 0; j < 4; j++) {
-					memset(&alu, 0, sizeof(struct r600_bytecode_alu));
-					alu.op = ALU_OP1_MOV;
-                                        r600_bytecode_src(&alu.src[0], &ctx->src[i], j);
-                                        alu.dst.sel = tex.src_gpr;
-                                        alu.dst.chan = j;
-                                        if (j == 3)
-                                                alu.last = 1;
-                                        alu.dst.write = 1;
-                                        r = r600_bytecode_add_alu(ctx->bc, &alu);
-                                        if (r)
-                                                return r;
-				}
-
-			} else {
-				tex.src_gpr = tgsi_tex_get_src_gpr(ctx, i);
-				tex.src_sel_x = ctx->src[i].swizzle[0];
-				tex.src_sel_y = ctx->src[i].swizzle[1];
-				tex.src_sel_z = ctx->src[i].swizzle[2];
-				tex.src_sel_w = ctx->src[i].swizzle[3];
-				tex.src_rel = ctx->src[i].rel;
-			}
 			tex.dst_gpr = ctx->temp_reg; /* just to avoid confusing the asm scheduler */
 			tex.dst_sel_x = tex.dst_sel_y = tex.dst_sel_z = tex.dst_sel_w = 7;
 			if (inst->Texture.Texture != TGSI_TEXTURE_RECT) {
-- 
1.9.3