pan/bi: Add op for ADD_FREXPM

Used in log2. Needs a new class as well due to scheduling silliness.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4615>

src/panfrost/bifrost/bi_print.c

@@ -272,6 +272,15 @@ bi_special_op_name(enum bi_special_op op)
         }
 }
 
+const char *
+bi_reduce_op_name(enum bi_reduce_op op)
+{
+        switch (op) {
+        case BI_REDUCE_ADD_FREXPM: return "add_frexpm";
+        default: return "invalid";
+        }
+}
+
 static void
 bi_print_load_vary(struct bi_load_vary *load, FILE *fp)
 {
@@ -339,6 +348,8 @@ bi_print_instruction(bi_instruction *ins, FILE *fp)
                 fprintf(fp, "%s", bi_special_op_name(ins->op.special));
         else if (ins->type == BI_TABLE)
                 fprintf(fp, "%s", bi_table_op_name(ins->op.table));
+        else if (ins->type == BI_REDUCE_FMA)
+                fprintf(fp, "%s", bi_reduce_op_name(ins->op.reduce));
         else if (ins->type == BI_CMP)
                 fprintf(fp, "%s", bi_cond_name(ins->op.compare));
         else

src/panfrost/bifrost/bi_print.h

@@ -42,6 +42,7 @@ const char * bi_class_name(enum bi_class cl);
 const char * bi_cond_name(enum bi_cond cond);
 const char * bi_special_op_name(enum bi_special_op op);
 const char * bi_table_op_name(enum bi_table_op op);
+const char * bi_reduce_op_name(enum bi_reduce_op op);
 
 void bi_print_instruction(bi_instruction *ins, FILE *fp);
 void bi_print_bundle(bi_bundle *bundle, FILE *fp);

src/panfrost/bifrost/bi_tables.c

@@ -48,6 +48,7 @@ unsigned bi_class_props[BI_NUM_CLASSES] = {
         [BI_MINMAX] 		= BI_GENERIC | BI_SCHED_ADD | BI_NO_ABS_ABS_FP16_FMA | BI_MODS, /* | FMA on some? */
         [BI_MOV] 		= BI_SCHED_ALL,
         [BI_FMOV]               = BI_MODS | BI_SCHED_ALL,
+        [BI_REDUCE_FMA]         = BI_SCHED_FMA,
         [BI_SHIFT] 		= BI_SCHED_ALL,
         [BI_STORE] 		= BI_SCHED_HI_LATENCY | BI_SCHED_ADD | BI_VECTOR | BI_DATA_REG_SRC,
         [BI_STORE_VAR] 		= BI_SCHED_HI_LATENCY | BI_SCHED_ADD | BI_VECTOR | BI_DATA_REG_SRC,

src/panfrost/bifrost/compiler.h

@@ -68,6 +68,7 @@ enum bi_class {
         BI_LOAD_VAR_ADDRESS,
         BI_MINMAX,
         BI_MOV,
+        BI_REDUCE_FMA,
         BI_SHIFT,
         BI_STORE,
         BI_STORE_VAR,
@@ -192,6 +193,13 @@ enum bi_table_op {
         BI_TABLE_LOG2_U_OVER_U_1_LOW,
 };
 
+enum bi_reduce_op {
+        /* Takes two fp32 arguments and returns x + frexp(y). Used in
+         * low-precision log2 argument reduction on newer models. */
+
+        BI_REDUCE_ADD_FREXPM,
+};
+
 enum bi_special_op {
         BI_SPECIAL_FRCP,
         BI_SPECIAL_FRSQ,
@@ -259,6 +267,7 @@ typedef struct {
                 enum bi_bitwise_op bitwise;
                 enum bi_round_op round;
                 enum bi_special_op special;
+                enum bi_reduce_op reduce;
                 enum bi_table_op table;
                 enum bi_cond compare;
         } op;

src/panfrost/bifrost/disassemble.c

@@ -553,6 +553,7 @@ static const struct fma_op_info FMAOpInfos[] = {
         { true,  0x01e08, "SEL.YX.i16", FMA_TWO_SRC },
         { true,  0x01e10, "SEL.XY.i16", FMA_TWO_SRC },
         { true,  0x01e18, "SEL.YY.i16", FMA_TWO_SRC },
+        { true,  0x01e80, "ADD_FREXPM.f32", FMA_TWO_SRC },
         { true,  0x00800, "IMAD", FMA_THREE_SRC },
         { true,  0x078db, "POPCNT", FMA_ONE_SRC },
 };