agx: Use AGX extr for tex lowering

Replaces a number of bit operations by a single extr instruction,
optimizing the extraction of the width from the packed value.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20628>

diff --git a/src/asahi/compiler/agx_nir_lower_texture.c b/src/asahi/compiler/agx_nir_lower_texture.c
index 873b00b..6fe5abe 100644 (file)
--- a/src/asahi/compiler/agx_nir_lower_texture.c
+++ b/src/asahi/compiler/agx_nir_lower_texture.c
@@ -78,8 +78,8 @@ agx_txs(nir_builder *b, nir_tex_instr *tex)
 
    /* Width minus 1: bits [28, 42) */
    nir_ssa_def *width_m1 =
-      nir_ior(b, nir_ushr_imm(b, w0, 28),
-              nir_ishl_imm(b, nir_iand_imm(b, w1, BITFIELD_MASK(14 - 4)), 4));
+      nir_extr_agx(b, w0, w1, nir_imm_int(b, 28), nir_imm_int(b, 14));
+
    /* Height minus 1: bits [42, 56) */
    nir_ssa_def *height_m1 =
       nir_iand_imm(b, nir_ushr_imm(b, w1, 42 - 32), BITFIELD_MASK(14));