A float inline constant (240-248) read by a 64-bit operand is the f64 bit
pattern for integer B64 opcodes too: AMD's compilers emit
v_lshrrev_b64 v[4:5], v0, 1.0 for 0x3ff0000000000000 >> lane. ReadU32Pair
returned {f32 bits, 0}, so only F64-typed reads had the right value.
Based on TheCruZ's 284deab28 (closed#1219).
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
V_PK_MIN_F16 and V_PK_MAX_F16 return the quieted NaN for a signaling NaN
operand and the other operand for a quiet one (per half, as V_MIN_F16 and
V_MAX_F16 do). The signaling test masked the half with 0x7c00 and checked
for a nonzero payload, so a quiet NaN with payload bits such as 0x7e01 was
taken as signaling and returned. Mask with 0x7e00 so the quiet bit must be
clear.
Two more vectors in PackedMinMaxF16NanAndSignedZeroEdges cover it.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
The 16-bit encodings of the float inline constants are fixed: the exact
halves of 0.5, 1.0, 2.0 and 4.0 and their negations, and 0x3118 for
1/(2*pi). Read16LaneBits converted the 32-bit value at run time instead,
through PackHalf2x16, which the AMD driver rounds toward zero, so
1/(2*pi) became 0x3117. Use the encodings directly.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
* shader: support DS_CMPST_RTN_B32
Assassin's Creed Valhalla (PPSA01490, #281) stops on DS opcode 0x30 in a
compute shader. DS compares DATA and stores DATA2, the opposite of
BUFFER_ATOMIC_CMPSWAP, so the 32-bit atomic path swaps the two for this
opcode, as the 64-bit form does.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* shader: reject unsupported GDS compare-store variant
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: nmzik <Nmzik@mail.ru>
Performance changes from #1495:
- Sync changed BDA ranges instead of scanning all mappings.
- Let VMA suballocate BDA buffers.
- Remove the renderer lock from presentation.
- Keep compatible pipeline caches across builds.
- Fold masked shifts that always produce zero.
* shader: pack v_cvt_pkrtz_f16_f32 with the native half conversion
The round-toward-zero pack was emulated with integer operations: about 20 to 30 operations
per half. GTA V uses it in 613 of its 656 pixel shaders, about 16 times in each G-buffer
pixel shader.
The pair is now packed with PackHalf2x16, unpacked again, and each half whose magnitude
exceeds its input's takes one unit off. Half signs and magnitudes are separate, so that is
the next value toward zero, whatever rounding the native conversion uses as long as it
returns one of the two neighbours. Same bits as before for every finite input and infinity;
a NaN stays a NaN. Checked against the old code on 2 million values on the CPU, and on an
Apple M5 GPU through Metal (400 000 values, subnormals included, safe and fast math).
GTA V on an Apple M5 (MoltenVK), 1080p, fixed script camera, three places, A B B A between
launches: -1.7 to -2.8 ms per frame (+4 to +6 %).
Scope: generic
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* shader: remove half-pack commentary and unused shift helper
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: nmzik <Nmzik@mail.ru>
nmzik