pan/bi: Add the control flow graph

We're starting to build up the IR data structures in preparation to get
everything piped through.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4061>

src/panfrost/bifrost/compiler.h

@@ -27,8 +27,60 @@
 #ifndef __BIFROST_COMPILER_H
 #define __BIFROST_COMPILER_H
 
+/* Bifrost opcodes are tricky -- the same op may exist on both FMA and
+ * ADD with two completely different opcodes, and opcodes can be varying
+ * length in some cases. Then we have different opcodes for int vs float
+ * and then sometimes even for different typesizes. Further, virtually
+ * every op has a number of flags which depend on the op. In constrast
+ * to Midgard where you have a strict ALU/LDST/TEX division and within
+ * ALU you have strict int/float and that's it... here it's a *lot* more
+ * involved. As such, we use something much higher level for our IR,
+ * encoding "classes" of operations, letting the opcode details get
+ * sorted out at emit time.
+ *
+ * Please keep this list alphabetized. Please use a dictionary if you
+ * don't know how to do that.
+ */
+
+enum bi_class {
+        BI_ADD,
+        BI_ATEST,
+        BI_BRANCH,
+        BI_CMP,
+        BI_BLEND,
+        BI_BITWISE,
+        BI_CONVERT,
+        BI_CSEL,
+        BI_DISCARD,
+        BI_FMA,
+        BI_FREXP,
+        BI_LOAD,
+        BI_LOAD_ATTR,
+        BI_LOAD_VAR,
+        BI_LOAD_VAR_ADDRESS,
+        BI_MINMAX,
+        BI_MOV,
+        BI_SHIFT,
+        BI_STORE,
+        BI_STORE_VAR,
+        BI_SPECIAL, /* _FAST, _TABLE on supported GPUs */
+        BI_TEX,
+        BI_ROUND,
+};
+
+typedef struct {
+        struct list_head link; /* Must be first */
+        enum bi_class type;
+} bi_instruction;
+
+typedef struct {
+        struct list_head link; /* must be first */
+        struct list_head instructions; /* list of bi_instructions */
+} bi_block;
+
 typedef struct {
        nir_shader *nir;
+       struct list_head blocks; /* list of bi_block */
 } bi_context; 
 
 #endif