Difference between revisions of "Tests of a SIMD version of DVector3"
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| − | * SIMD (Single-Instruction Multiple-Data) instructions provide means of doing multiple calculations or manipulations of several pieces of data with a single operation | + | * SIMD (Single-Instruction Multiple-Data) instructions provide means of doing multiple calculations with or manipulations of several pieces of data with a single operation |
** Size of special registers is 128 bits: can do 4 single-precision floating point calculations (SSE) or 2 double-precision floating point calculations (SSE2) at the same time | ** Size of special registers is 128 bits: can do 4 single-precision floating point calculations (SSE) or 2 double-precision floating point calculations (SSE2) at the same time | ||
** Basic arithmetic and logical operations are supported, as are square roots and reciprocal square roots | ** Basic arithmetic and logical operations are supported, as are square roots and reciprocal square roots | ||
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** Three pairs of coordinates: ''xy'',''yz'',''zx'' | ** Three pairs of coordinates: ''xy'',''yz'',''zx'' | ||
** gcc compiler flags: -msse2 -mfpmath=sse -O2 | ** gcc compiler flags: -msse2 -mfpmath=sse -O2 | ||
| − | * Compare to TVector3 on ifarml6: | + | * Compare to TVector3 on ifarml6: 10 million events with randomly generated vectors |
| + | <pre> | ||
| + | Operation DVector3 time (s) TVector3 time (s) T3/D3 | ||
| + | ----------------------------------------------------------------- | ||
| + | v2=-v1 0.054 0.171 3.17 | ||
| + | v3=v1+v2 0.092 0.191 2.08 | ||
| + | v3+=v1 0.056 0.048 0.86 <- | ||
| + | v3=v1-v2 0.092 0.194 2.11 | ||
| + | v2=k v1 0.054 0.174 3.24 | ||
| + | v2*=k 0.030 0.018 0.60 <- | ||
| + | SetMag 0.198 0.198 1.00 | ||
| + | SetXYZ 0.007 0.008 1.14 | ||
| + | SetMagThetaPhi 0.680 0.890 1.31 Expensive! | ||
| + | Rotate(a,v) 0.625 1.528 2.44 " | ||
| + | RotateZ(a) 0.353 0.402 1.14 | ||
| + | make orthogonal v 0.142 0.273 1.92 | ||
| + | v3 = v1 x v2 0.107 0.193 1.80 | ||
| + | </pre> | ||
Revision as of 08:05, 4 May 2010
- SIMD (Single-Instruction Multiple-Data) instructions provide means of doing multiple calculations with or manipulations of several pieces of data with a single operation
- Size of special registers is 128 bits: can do 4 single-precision floating point calculations (SSE) or 2 double-precision floating point calculations (SSE2) at the same time
- Basic arithmetic and logical operations are supported, as are square roots and reciprocal square roots
- Implemented DVector3 with SSE2 instructions
- Three pairs of coordinates: xy,yz,zx
- gcc compiler flags: -msse2 -mfpmath=sse -O2
- Compare to TVector3 on ifarml6: 10 million events with randomly generated vectors
Operation DVector3 time (s) TVector3 time (s) T3/D3 ----------------------------------------------------------------- v2=-v1 0.054 0.171 3.17 v3=v1+v2 0.092 0.191 2.08 v3+=v1 0.056 0.048 0.86 <- v3=v1-v2 0.092 0.194 2.11 v2=k v1 0.054 0.174 3.24 v2*=k 0.030 0.018 0.60 <- SetMag 0.198 0.198 1.00 SetXYZ 0.007 0.008 1.14 SetMagThetaPhi 0.680 0.890 1.31 Expensive! Rotate(a,v) 0.625 1.528 2.44 " RotateZ(a) 0.353 0.402 1.14 make orthogonal v 0.142 0.273 1.92 v3 = v1 x v2 0.107 0.193 1.80
