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More SPU patterns #15211

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More SPU patterns #15211

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RipleyTom
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  • Simplified re_accurate pattern and fixed an edge case in the intrinsic
  • Fixed and simplified sqrt pattern(still need to test accuracy)
  • Added an alternative re_accurate pattern used by GOW3 that should give the same result

@Megamouse Megamouse added CPU LLVM Related to LLVM instruction decoders labels Feb 15, 2024
@Ordinary205
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This PR breaks NFS Most Wanted audio on Approximate XFloat. This doesnt happen on the latest build.
RPCS3.log.gz

const auto bitcast_float = bitcast<u32[4]>(cursed_float);
set_vr(op.rt4, select(bitcast_float == splat<u32[4]>(0x3F800000) | bitcast_float == splat<u32[4]>(0x3F800001), fsqrt(fabs(x)), fma(fnms(spu_rsqrte(x), c, cursed_float), fm(fsplat<f32[4]>(0.5f), fm(x, spu_rsqrte(x))), fm(x, spu_rsqrte(x)))));
const auto bitcast_float = bitcast<u32[4]>(fnms_float);
set_vr(op.rt4, select(fcmp_uno(fm_float == fsplat<f32[4]>(0.5f)) & (bitcast_float == splat<u32[4]>(0x3F800000) | bitcast_float == splat<u32[4]>(0x3F800001)), fsqrt(fabs(x)), fma(fnms(spu_rsqrte(x), c, fnms_float), fm(fm_float, fm(x, spu_rsqrte(x))), fm(x, spu_rsqrte(x)))));
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select evaluates all its arguments, its why it exists (so it would be branch-less)
So this would perform worse.
You can use conditional jumps

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4 participants