On 4/2/21 3:04 PM, Matteo Bruni wrote:
On Wed, Mar 31, 2021 at 12:04 AM Zebediah Figura zfigura@codeweavers.com wrote:
Signed-off-by: Zebediah Figura zfigura@codeweavers.com
libs/vkd3d-shader/hlsl.c | 4 +- libs/vkd3d-shader/hlsl.h | 9 ++ libs/vkd3d-shader/hlsl_codegen.c | 184 +++++++++++++++++++++++++++++++ 3 files changed, 195 insertions(+), 2 deletions(-)
This code feels strangely familiar ;)
I have some nitpicks, as usual.
diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c index dbd591af..420e720f 100644 --- a/libs/vkd3d-shader/hlsl_codegen.c +++ b/libs/vkd3d-shader/hlsl_codegen.c @@ -612,6 +612,188 @@ static void compute_liveness(struct hlsl_ctx *ctx, struct hlsl_ir_function_decl compute_liveness_recurse(entry_func->body, 0, 0); }
+struct liveness +{
- size_t size;
- struct
- {
/* 0 if not live yet. */unsigned int last_read;- } *regs;
+};
+static unsigned char get_available_writemask(struct liveness *liveness,
unsigned int first_write, unsigned int index, unsigned int components)+{
- unsigned char i, writemask = 0, count = 0;
- for (i = 0; i < 4; ++i)
- {
if (liveness->regs[index + i].last_read <= first_write){writemask |= 1 << i;if (++count == components)return writemask;}- }
- return 0;
+}
+static bool resize_liveness(struct liveness *liveness, size_t new_count) +{
- size_t old_capacity = liveness->size;
- if (!vkd3d_array_reserve((void **)&liveness->regs, &liveness->size, new_count, sizeof(*liveness->regs)))
return false;- if (liveness->size > old_capacity)
memset(liveness->regs + old_capacity, 0, (liveness->size - old_capacity) * sizeof(*liveness->regs));- return true;
+}
+static struct hlsl_reg allocate_register(struct liveness *liveness,
unsigned int first_write, unsigned int last_read, unsigned char components)This is the only instance of "components" (which actually should be "component_count") that isn't unsigned int. I assume there was some back and forth while writing the patch.
Yep...
(Can you tell this patch is very old?)
+{
- struct hlsl_reg ret = {.allocated = true};
- unsigned char writemask, i;
- unsigned int regnum;
No reason to use an unsigned char for writemask or i. "regnum" should probably be "index" (or "base_index", or "base", or something).
- for (regnum = 0; regnum < liveness->size; regnum += 4)
- {
if ((writemask = get_available_writemask(liveness, first_write, regnum, components)))break;- }
- if (regnum == liveness->size)
- {
if (!resize_liveness(liveness, regnum + 4))return ret;writemask = (1 << components) - 1;1u (also elsewhere).
- }
- for (i = 0; i < 4; ++i)
- {
if (writemask & (1 << i))liveness->regs[regnum + i].last_read = last_read;- }
- ret.id = regnum / 4;
- ret.writemask = writemask;
- return ret;
+}
+static bool is_range_available(struct liveness *liveness, unsigned int first_write,
unsigned int index, unsigned int elements)+{
- unsigned int i;
- for (i = 0; i < elements; i += 4)
- {
if (!get_available_writemask(liveness, first_write, index + i, 4))return false;- }
- return true;
+}
+/* "elements" is the total number of consecutive whole registers needed. */
Let's call it register_count or element_count. Or just count.
+static void allocate_variable_temp_register(struct hlsl_ir_var *var, struct liveness *liveness) +{
- if (var->is_input_varying || var->is_output_varying || var->is_uniform)
return;- if (!var->reg.allocated && var->last_read)
- {
if (var->data_type->reg_size > 1)var->reg = allocate_range(liveness, var->first_write,var->last_read, var->data_type->reg_size);elsevar->reg = allocate_register(liveness, var->first_write,var->last_read, var->data_type->dimx);TRACE("Allocated %s to %s (liveness %u-%u).\n", debug_register('r', var->reg, var->data_type),var->name, var->first_write, var->last_read);- }
I guess both work, but it sounds better to me as "Allocated <variable name> to <register>".
+}
+static void allocate_temp_registers_recurse(struct list *instrs, struct liveness *liveness) +{
- struct hlsl_ir_node *instr;
- LIST_FOR_EACH_ENTRY(instr, instrs, struct hlsl_ir_node, entry)
- {
switch (instr->type){case HLSL_IR_ASSIGNMENT:Entirely an aside: ASSIGNMENT looks pretty ugly now that we have LOAD for the symmetric operation and that the IR has been reworked into a somewhat proper load / store architecture. Up to you when (or if) to do a compiler-wide rename, just know that every time I read HLSL_IR_ASSIGNMENT I feel a tiiiiiiny bit of pain :P
Yeah, that was on my list to do 'eventually', but now is a good time :D
{struct hlsl_ir_assignment *assignment = hlsl_ir_assignment(instr);allocate_variable_temp_register(assignment->lhs.var, liveness);break;}case HLSL_IR_IF:{struct hlsl_ir_if *iff = hlsl_ir_if(instr);allocate_temp_registers_recurse(&iff->then_instrs, liveness);allocate_temp_registers_recurse(&iff->else_instrs, liveness);break;}case HLSL_IR_LOAD:{struct hlsl_ir_load *load = hlsl_ir_load(instr);allocate_variable_temp_register(load->src.var, liveness);break;}This one is required because of input arguments and uniforms, I gather. Maybe a comment would be useful? I am not sure, honestly.
Assuming I understand correctly, I don't think it's necessary per se (we may have to assign them to a temp reg for valid DXBC, but 3d22df25fe1 and friends already give us a temp variable for that purpose).
A more salient reason is that the variable itself can be modified in the meantime, which in practice happens with postincrement.