freedreno/ir3: add last-baryf shaderdb stat

Sometimes sched changes that are a win in terms of instruction count
and/or register pressure, are worse in real life, due to keeping varying
storage locked for too long.  Add a shader-db stat to give this more
visibility.

Signed-off-by: Rob Clark <robdclark@chromium.org>

src/freedreno/ir3/ir3.c

 			int ret = emit[opc_cat(instr->opc)](instr, dwords, info);
 			if (ret)
 				goto fail;
+
+			if ((instr->opc == OPC_BARY_F) && (instr->regs[0]->flags & IR3_REG_EI))
+				info->last_baryf = info->instrs_count;
+
 			info->instrs_count += 1 + instr->repeat + instr->nop;
 			info->nops_count += instr->nop;
 			if (instr->opc == OPC_NOP)

src/freedreno/ir3/ir3.h

 
 	/* number of sync bits: */
 	uint16_t ss, sy;
+
+	uint16_t last_baryf;     /* instruction # of last varying fetch */
 };
 
 struct ir3_register {

src/gallium/drivers/freedreno/ir3/ir3_gallium.c

 
 	pipe_debug_message(debug, SHADER_INFO,
 			"%s shader: %u inst, %u nops, %u non-nops, %u dwords, "
-			"%u half, %u full, %u constlen, "
+			"%u last-baryf, %u half, %u full, %u constlen, "
 			"%u (ss), %u (sy), %d max_sun, %d loops\n",
 			ir3_shader_stage(v),
 			v->info.instrs_count,
 			v->info.nops_count,
 			v->info.instrs_count - v->info.nops_count,
 			v->info.sizedwords,
+			v->info.last_baryf,
 			v->info.max_half_reg + 1,
 			v->info.max_reg + 1,
 			v->constlen,