[Mesa-dev] [PATCH 48.1/59 v2] nir: Shift count for shift opcodes is always 32-bits

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

Previously both sources were unsized.  This caused problems when the
thing being shifted was 64-bit but the shift count was 32-bit.  The
expectation in NIR is that all unsized sources (and destination) will
ultimately have the same size.

The changes in nir_opt_algebraic.py are to prevent errors like:

 Failed to parse transformation:
03:12:25   (('extract_i8', 'a', 'b'), ('ishr', ('ishl', 'a', ('imul', ('isub', 3, 'b'), 8)), 24), 'options->lower_extract_byte')
03:12:25 Traceback (most recent call last):
03:12:25   File "/home/jenkins/workspace/Leeroy_2/repos/mesa/src/compiler/nir/nir_algebraic.py", line 610, in __init__
03:12:25     xform = SearchAndReplace(xform)
03:12:25   File "/home/jenkins/workspace/Leeroy_2/repos/mesa/src/compiler/nir/nir_algebraic.py", line 495, in __init__
03:12:25     BitSizeValidator(varset).validate(self.search, self.replace)
03:12:25   File "/home/jenkins/workspace/Leeroy_2/repos/mesa/src/compiler/nir/nir_algebraic.py", line 311, in validate
03:12:25     validate_dst_class = self._validate_bit_class_up(replace)
03:12:25   File "/home/jenkins/workspace/Leeroy_2/repos/mesa/src/compiler/nir/nir_algebraic.py", line 414, in _validate_bit_class_up
03:12:25     src_class = self._validate_bit_class_up(val.sources[i])
03:12:25   File "/home/jenkins/workspace/Leeroy_2/repos/mesa/src/compiler/nir/nir_algebraic.py", line 420, in _validate_bit_class_up
03:12:25     assert src_class == src_type_bits
03:12:25 AssertionError

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Suggested-by: Connor Abbott <cwabbott0 at gmail.com>
Cc: Connor Abbott <cwabbott0 at gmail.com>
Cc: Jason Ekstrand <jason at jlekstrand.net>
---

I will blame the cold medicine, but when I read Connor's statement,
"legal for one input to be explicitly sized while the other is unsized"
I parsed it more like "legal for one input to be one size while the
other is another sized".  The latter is quite a bit more general than
the former.  Oops.

 src/compiler/nir/nir_opcodes.py       | 6 +++---
 src/compiler/nir/nir_opt_algebraic.py | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/compiler/nir/nir_opcodes.py b/src/compiler/nir/nir_opcodes.py
index 1825dc3..2af146a 100644
--- a/src/compiler/nir/nir_opcodes.py
+++ b/src/compiler/nir/nir_opcodes.py
@@ -497,9 +497,9 @@ binop("seq", tfloat32, commutative, "(src0 == src1) ? 1.0f : 0.0f") # Set on Equ
 binop("sne", tfloat32, commutative, "(src0 != src1) ? 1.0f : 0.0f") # Set on Not Equal
 
 
-binop("ishl", tint, "", "src0 << src1")
-binop("ishr", tint, "", "src0 >> src1")
-binop("ushr", tuint, "", "src0 >> src1")
+opcode("ishl", 0, tint, [0, 0], [tint, tuint32], "", "src0 << src1")
+opcode("ishr", 0, tint, [0, 0], [tint, tuint32], "", "src0 >> src1")
+opcode("ushr", 0, tuint, [0, 0], [tuint, tuint32], "", "src0 >> src1")
 
 # bitwise logic operators
 #
diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index 82d92f4..5e384d9 100644
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -341,19 +341,19 @@ optimizations = [
               ('ubfe', 'value', 'offset', 'bits')),
     'options->lower_bitfield_extract'),
 
-   (('extract_i8', a, b),
+   (('extract_i8', a, 'b at 32'),
     ('ishr', ('ishl', a, ('imul', ('isub', 3, b), 8)), 24),
     'options->lower_extract_byte'),
 
-   (('extract_u8', a, b),
+   (('extract_u8', a, 'b at 32'),
     ('iand', ('ushr', a, ('imul', b, 8)), 0xff),
     'options->lower_extract_byte'),
 
-   (('extract_i16', a, b),
+   (('extract_i16', a, 'b at 32'),
     ('ishr', ('ishl', a, ('imul', ('isub', 1, b), 16)), 16),
     'options->lower_extract_word'),
 
-   (('extract_u16', a, b),
+   (('extract_u16', a, 'b at 32'),
     ('iand', ('ushr', a, ('imul', b, 16)), 0xffff),
     'options->lower_extract_word'),
 
-- 
2.5.5