[Mesa-dev] [PATCH 13/78] i965/nir/vec4: Implement conditional statements (nir_cf_node_if)

[Eduardo Lima Mitev]

From: Iago Toral Quiroga <itoral at igalia.com>

The same we do in the FS NIR backend, only that here we need to consider
the number of components in the condition and adjust the swizzle
accordingly.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89580
---
 src/mesa/drivers/dri/i965/brw_vec4_nir.cpp | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
index 1ec75ee..d81b6a7 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
@@ -314,7 +314,28 @@ vec4_visitor::nir_emit_cf_list(exec_list *list)
 void
 vec4_visitor::nir_emit_if(nir_if *if_stmt)
 {
-   /* @TODO: Not yet implemented */
+   /* First, put the condition in f0 */
+   src_reg condition = get_nir_src(if_stmt->condition, BRW_REGISTER_TYPE_D);
+
+   int num_components = if_stmt->condition.is_ssa ?
+      if_stmt->condition.ssa->num_components :
+      if_stmt->condition.reg.reg->num_components;
+
+   condition.swizzle = brw_swizzle_for_size(num_components);
+
+   vec4_instruction *inst = emit(MOV(dst_null_d(), condition));
+   inst->conditional_mod = BRW_CONDITIONAL_NZ;
+
+   emit(IF(BRW_PREDICATE_NORMAL));
+
+   nir_emit_cf_list(&if_stmt->then_list);
+
+   /* note: if the else is empty, dead CF elimination will remove it */
+   emit(BRW_OPCODE_ELSE);
+
+   nir_emit_cf_list(&if_stmt->else_list);
+
+   emit(BRW_OPCODE_ENDIF);
 }
 
 void
-- 
2.1.4