mulMat3x4 / mulMat3x4InPlace: translation row had A*B operands swapped.
Original computes A_translation * B_rotation + B_translation, but our
code was doing A_rotation * B_translation + A_translation. Verified by
tracing x87 disassembly: first element loads A[9]*B[col] pattern.
Fixed in both silicon_sse.zig and silicon.zig.
packParticleColor: x87 rounds 127.5 to 128 (round-to-nearest), but SSE
@intFromFloat truncates to 127. Added @round() before @intFromFloat.
42/42 benchmarks now pass correctness. 0 MISMATCHes.
Extracted via Ghidra from WoW.exe for the 22 silicon SSE functions that
don't overlap with ssemaths addresses. These cover frustum culling,
bounding volume transforms, quaternion slerp, matrix operations, and
various geometry functions. Ready for benchmarking.
Inlined benchmarks use x87 inline asm vs direct Zig @Vector code with
no CALL/RET on either side. Shows the true instruction-level comparison
that in-place patching would achieve:
dotProduct: x87=3 SSE=1 -> 3.0x (was 0.3x when called)
evalPoly: x87=4 SSE=1 -> 4.0x (was 0.7x when called)
vec3MulScal: x87=3 SSE=2 -> 1.5x (was 0.8x when called)
Every "loser" from the called benchmarks flips to a winner when inlined.
The entire performance gap was function call overhead (~5 cycles), not
instruction quality. Confirms in-place patching as the right strategy.
Also added RADV_TEX_ANISO env var exploration item to release notes and
updated math polyfill section with full benchmark breakdown.
In-place functions (vec3MulAssign, scaleByVec, etc.) were showing fake
speedups (121x, 10x) because repeated application on the same data
caused values to overflow to Inf/NaN. x87 FPU traps on denormals while
SSE handles them in hardware, making the comparison meaningless.
Now each iteration resets from a template copy. Real results show these
functions are ~1.0x (neutral), not 100x wins. The actual winners are
rotMat3x3/4x4 at 2.1x, and several functions where our scalar-through-
pointers approach is slower than the original x87 pipeline (dotProduct
0.3x, evaluatePolynomial 0.4x) — candidates for real SIMD optimization.
Extracts original x87 FPU bytes from WoW.exe via Ghidra, mmaps them
executable, and benchmarks against our SSE replacements. Covers all 17
UnitXP polyfill functions with correctness validation and cycle counts.
Maps a page at 0x7ff000 for the float 1.0 constant referenced by
rotMat3x3/rotMat4x4/planeNormal via absolute address 0x7ff9d8.
Build: zig build bench / zig build run-bench
MarcelineVQ