diff options
| author | Matt Turner <[email protected]> | 2016-01-21 09:09:48 -0800 |
|---|---|---|
| committer | Matt Turner <[email protected]> | 2016-03-04 11:52:34 -0800 |
| commit | 76289fbfa84a06ef4db8ad44ea0eb88ad0be8d5c (patch) | |
| tree | f717a958caa3d752ff62fde104ea7ecccdde8f8b | |
| parent | 01e92e7010aebee111e70bdc18081b483511cac0 (diff) | |
nir: Recognize open-coded extract_u8.
Two shaders that appear in Unigine benchmarks (Heaven and Valley) unpack
three bytes from an integer and convert each into a float:
float((val >> 16u) & 0xffu)
float((val >> 8u) & 0xffu)
float((val >> 0u) & 0xffu)
Instead of shifting, masking, and type converting like this:
shr(8) g15<1>UD g25<8,8,1>UD 0x00000010UD
and(8) g16<1>UD g15<8,8,1>UD 0x000000ffUD
mov(8) g17<1>F g16<8,8,1>UD
shr(8) g18<1>UD g25<8,8,1>UD 0x00000008UD
and(8) g19<1>UD g18<8,8,1>UD 0x000000ffUD
mov(8) g20<1>F g19<8,8,1>UD
and(8) g21<1>UD g25<8,8,1>UD 0x000000ffUD
mov(8) g22<1>F g21<8,8,1>UD
i965 can simply extract a byte and convert to float in a single
instruction:
mov(8) g17<1>F g25.2<32,8,4>UB
mov(8) g20<1>F g25.1<32,8,4>UB
mov(8) g22<1>F g25.0<32,8,4>UB
This patch implements the first step: recognizing byte extraction. A
later patch will optimize out the conversion to float.
instructions in affected programs: 28568 -> 27450 (-3.91%)
helped: 7
cycles in affected programs: 210076 -> 203144 (-3.30%)
helped: 7
This patch decreases the number of instructions in the two Unigine
programs by:
#1721: 4520 -> 4374 instructions (-3.23%)
#1706: 3752 -> 3582 instructions (-4.53%)
Reviewed-by: Kenneth Graunke <[email protected]>
Reviewed-by: Iago Toral Quiroga <[email protected]>
| -rw-r--r-- | src/compiler/nir/nir_opt_algebraic.py | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index cc2c2299ab9..dd26805e1a8 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -162,6 +162,7 @@ optimizations = [ (('ishr', a, 0), a), (('ushr', 0, a), 0), (('ushr', a, 0), a), + (('iand', 0xff, ('ushr', a, 24)), ('ushr', a, 24)), # Exponential/logarithmic identities (('fexp2', ('flog2', a)), a), # 2^lg2(a) = a (('flog2', ('fexp2', a)), a), # lg2(2^a) = a @@ -213,6 +214,12 @@ optimizations = [ (('f2i', ('ftrunc', a)), ('f2i', a)), (('f2u', ('ftrunc', a)), ('f2u', a)), + # Byte extraction + (('ushr', a, 24), ('extract_u8', a, 3), '!options->lower_extract_byte'), + (('iand', 0xff, ('ushr', a, 16)), ('extract_u8', a, 2), '!options->lower_extract_byte'), + (('iand', 0xff, ('ushr', a, 8)), ('extract_u8', a, 1), '!options->lower_extract_byte'), + (('iand', 0xff, a), ('extract_u8', a, 0), '!options->lower_extract_byte'), + # Subtracts (('fsub', a, ('fsub', 0.0, b)), ('fadd', a, b)), (('isub', a, ('isub', 0, b)), ('iadd', a, b)), |