diff options
| author | Eric Anholt <[email protected]> | 2018-05-04 13:33:47 -0700 |
|---|---|---|
| committer | Eric Anholt <[email protected]> | 2018-06-06 13:44:28 -0700 |
| commit | d4c7c3c225b7c34669498c15c2d3186cf6a4647e (patch) | |
| tree | 4e8b71ad3e41a486ec8533c95260022df422aca4 | |
| parent | af88acf4c4e2e14161872752fb9fb4683f9c8845 (diff) | |
nir: Add lowering for ifind_msb to ufind_msb.
ufind_msb is easily expressed in terms of clz, and we can reduce ifind_msb
to that.
Reviewed-by: Matt Turner <[email protected]>
Reviewed-by: Ian Romanick <[email protected]>
| -rw-r--r-- | src/compiler/nir/nir.h | 2 | ||||
| -rw-r--r-- | src/compiler/nir/nir_opt_algebraic.py | 4 |
2 files changed, 6 insertions, 0 deletions
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 519c0198879..9fca61f0070 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -1913,6 +1913,8 @@ typedef struct nir_shader_compiler_options { bool lower_bitfield_insert_to_shifts; /** Lowers bfm to shifts and subtracts. */ bool lower_bfm; + /** Lowers ifind_msb to compare and ufind_msb */ + bool lower_ifind_msb; bool lower_uadd_carry; bool lower_usub_borrow; /** lowers fneg and ineg to fsub and isub. */ diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index eaa8b141640..f6685977f3a 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -555,6 +555,10 @@ optimizations = [ ('bfm', 'bits', 0))), 'options->lower_bitfield_extract_to_shifts'), + (('ifind_msb', 'value'), + ('ufind_msb', ('bcsel', ('ilt', 'value', 0), ('inot', 'value'), 'value')), + 'options->lower_ifind_msb'), + (('extract_i8', a, 'b@32'), ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24), 'options->lower_extract_byte'), |