freedreno/ir3: Add workaround for VS samgq

This instruction needs a workaround when used from vertex shaders.

Fixes:

  dEQP-GLES3.functional.shaders.texture_functions.texturegradoffset.sampler2dshadow_vertex
  dEQP-GLES3.functional.shaders.texture_functions.texturegradoffset.sampler3d_fixed_vertex
  dEQP-GLES3.functional.shaders.texture_functions.texturegradoffset.sampler3d_float_vertex
  dEQP-GLES3.functional.shaders.texture_functions.textureprojgradoffset.sampler2dshadow_vertex
  dEQP-GLES3.functional.shaders.texture_functions.textureprojgradoffset.sampler3d_fixed_vertex
  dEQP-GLES3.functional.shaders.texture_functions.textureprojgradoffset.sampler3d_float_vertex
  dEQP-GLES3.functional.shaders.texture_functions.textureprojgrad.sampler2dshadow_vertex

Signed-off-by: Kristian H. Kristensen <hoegsberg@chromium.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>

src/freedreno/ir3/ir3.c

@@ -46,11 +46,12 @@ void * ir3_alloc(struct ir3 *shader, int sz)
 }
 
 struct ir3 * ir3_create(struct ir3_compiler *compiler,
-		unsigned nin, unsigned nout)
+		gl_shader_stage type, unsigned nin, unsigned nout)
 {
 	struct ir3 *shader = rzalloc(compiler, struct ir3);
 
 	shader->compiler = compiler;
+	shader->type = type;
 	shader->ninputs = nin;
 	shader->inputs = ir3_alloc(shader, sizeof(shader->inputs[0]) * nin);
 

src/freedreno/ir3/ir3.h

@@ -408,6 +408,7 @@ static inline int ir3_neighbor_count(struct ir3_instruction *instr)
 
 struct ir3 {
 	struct ir3_compiler *compiler;
+	gl_shader_stage type;
 
 	unsigned ninputs, noutputs;
 	struct ir3_instruction **inputs;
@@ -523,7 +524,7 @@ block_id(struct ir3_block *block)
 }
 
 struct ir3 * ir3_create(struct ir3_compiler *compiler,
-		unsigned nin, unsigned nout);
+		gl_shader_stage type, unsigned nin, unsigned nout);
 void ir3_destroy(struct ir3 *shader);
 void * ir3_assemble(struct ir3 *shader,
 		struct ir3_info *info, uint32_t gpu_id);

src/freedreno/ir3/ir3_compiler.c

@@ -52,6 +52,10 @@ struct ir3_compiler * ir3_compiler_create(struct fd_device *dev, uint32_t gpu_id
 	compiler->gpu_id = gpu_id;
 	compiler->set = ir3_ra_alloc_reg_set(compiler);
 
+	if (compiler->gpu_id >= 600) {
+		compiler->samgq_workaround = true;
+	}
+
 	if (compiler->gpu_id >= 400) {
 		/* need special handling for "flat" */
 		compiler->flat_bypass = true;

src/freedreno/ir3/ir3_compiler.h

@@ -63,6 +63,10 @@ struct ir3_compiler {
 	 * index coordinate:
 	 */
 	bool array_index_add_half;
+
+	/* on a6xx, rewrite samgp to sequence of samgq0-3 in vertex shaders:
+	 */
+	bool samgq_workaround;
 };
 
 struct ir3_compiler * ir3_compiler_create(struct fd_device *dev, uint32_t gpu_id);

src/freedreno/ir3/ir3_compiler_nir.c

@@ -2438,7 +2438,7 @@ emit_instructions(struct ir3_context *ctx)
 	 */
 	ninputs += max_sysvals[ctx->so->type];
 
-	ctx->ir = ir3_create(ctx->compiler, ninputs, noutputs);
+	ctx->ir = ir3_create(ctx->compiler, ctx->so->type, ninputs, noutputs);
 
 	/* Create inputs in first block: */
 	ctx->block = get_block(ctx, nir_start_block(fxn));

src/freedreno/ir3/ir3_legalize.c

@@ -41,6 +41,7 @@
 
 struct ir3_legalize_ctx {
 	struct ir3_compiler *compiler;
+	gl_shader_stage type;
 	bool has_ssbo;
 	bool need_pixlod;
 	int max_bary;
@@ -212,7 +213,20 @@ legalize_block(struct ir3_legalize_ctx *ctx, struct ir3_block *block)
 			}
 		}
 
-		list_addtail(&n->node, &block->instr_list);
+		if (ctx->compiler->samgq_workaround &&
+			ctx->type == MESA_SHADER_VERTEX && n->opc == OPC_SAMGQ) {
+			struct ir3_instruction *samgp;
+
+			for (i = 0; i < 4; i++) {
+				samgp = ir3_instr_clone(n);
+				samgp->opc = OPC_SAMGP0 + i;
+				if (i > 1)
+					samgp->flags |= IR3_INSTR_SY;
+			}
+			list_delinit(&n->node);
+		} else {
+			list_addtail(&n->node, &block->instr_list);
+		}
 
 		if (is_sfu(n))
 			regmask_set(&state->needs_ss, n->regs[0]);
@@ -480,6 +494,7 @@ ir3_legalize(struct ir3 *ir, bool *has_ssbo, bool *need_pixlod, int *max_bary)
 
 	ctx->max_bary = -1;
 	ctx->compiler = ir->compiler;
+	ctx->type = ir->type;
 
 	/* allocate per-block data: */
 	list_for_each_entry (struct ir3_block, block, &ir->block_list, node) {