bifrost: Add support for nir_op_iabs

Signed-off-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6098>

src/panfrost/bifrost/bi_pack.c

@@ -1434,6 +1434,9 @@ bi_pack_add_special(bi_instruction *ins, bi_registers *regs)
         } else if (ins->op.special == BI_SPECIAL_EXP2_LOW) {
                 assert(!fp16);
                 op = BIFROST_ADD_OP_FEXP2_FAST;
+        } else if (ins->op.special == BI_SPECIAL_IABS) {
+                assert(ins->src_types[0] == nir_type_int32);
+                op = BIFROST_ADD_OP_IABS_32;
         } else {
                 unreachable("Unknown special op");
         }

src/panfrost/bifrost/bifrost.h

@@ -164,6 +164,7 @@ struct bifrost_fma_mscale {
 #define BIFROST_ADD_OP_FRSQ_FAST_F16_Y (0x0ce70)
 #define BIFROST_ADD_OP_LOG2_HELP  (0x0cc68)
 #define BIFROST_ADD_OP_FEXP2_FAST (0x0cd58)
+#define BIFROST_ADD_OP_IABS_32 (0x07bd4)
 
 struct bifrost_add_inst {
         unsigned src0 : 3;

src/panfrost/bifrost/bifrost_compile.c

@@ -600,6 +600,7 @@ bi_class_for_nir_alu(nir_op op)
 
         case nir_op_frcp:
         case nir_op_frsq:
+        case nir_op_iabs:
                 return BI_SPECIAL;
 
         default:
@@ -808,6 +809,9 @@ emit_alu(bi_context *ctx, nir_alu_instr *instr)
         case nir_op_isub:
                 alu.op.imath = BI_IMATH_SUB;
                 break;
+        case nir_op_iabs:
+                alu.op.special = BI_SPECIAL_IABS;
+                break;
         case nir_op_inot:
                 /* no dedicated bitwise not, but we can invert sources. convert to ~a | 0 */
                 alu.op.bitwise = BI_BITWISE_OR;

src/panfrost/bifrost/compiler.h

@@ -204,6 +204,7 @@ enum bi_special_op {
          * exp2() in GL. In the first argument, it takes f2i_rte(x * 2^24). In
          * the second, it takes x itself. */
         BI_SPECIAL_EXP2_LOW,
+        BI_SPECIAL_IABS,
 };
 
 enum bi_tex_op {

src/panfrost/bifrost/disassemble.c

@@ -1013,6 +1013,7 @@ static const struct add_op_info add_op_infos[] = {
         { 0x07ba5, "FSQRT_FREXPE", ADD_ONE_SRC },
         { 0x07bad, "FRSQ_FREXPE", ADD_ONE_SRC },
         { 0x07bc5, "FLOG_FREXPE", ADD_ONE_SRC },
+        { 0x07bd4, "IABS.i32", ADD_ONE_SRC },
         { 0x07d42, "CEIL.v2f16", ADD_ONE_SRC },
         { 0x07d45, "CEIL.f32", ADD_ONE_SRC },
         { 0x07d82, "FLOOR.v2f16", ADD_ONE_SRC },