bindings/go: parallelize MSM for N<32.

supranational · Jul 24, 2024 · 1a89355 · 1a89355
1 parent e4be9e6
commit 1a89355
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Showing 4 changed files with 212 additions and 3 deletions.
diff --git a/bindings/go/blst.go b/bindings/go/blst.go
@@ -2112,7 +2112,7 @@ func P1AffinesMult(pointsIf interface{}, scalarsIf interface{}, nbits int) *P1 {
 
 	numThreads := numThreads(0)
 
-	if numThreads < 2 || npoints < 32 {
+	if numThreads < 2 {
 		sz := int(C.blst_p1s_mult_pippenger_scratch_sizeof(C.size_t(npoints))) / 8
 		scratch := make([]uint64, sz)
 
@@ -2161,6 +2161,71 @@ func P1AffinesMult(pointsIf interface{}, scalarsIf interface{}, nbits int) *P1 {
 		return &ret
 	}
 
+	if npoints < 32 {
+		if numThreads > npoints {
+			numThreads = npoints
+		}
+
+		curItem := uint32(0)
+		msgs := make(chan P1, numThreads)
+
+		for tid := 0; tid < numThreads; tid++ {
+			go func() {
+				var acc P1
+
+				for {
+					workItem := int(atomic.AddUint32(&curItem, 1) - 1)
+					if workItem >= npoints {
+						break
+					}
+
+					var point *P1Affine
+					switch val := pointsIf.(type) {
+					case []*P1Affine:
+						point = val[workItem]
+					case []P1Affine:
+						point = &val[workItem]
+					case P1Affines:
+						point = &val[workItem]
+					}
+
+					var scalar *C.byte
+					switch val := scalarsIf.(type) {
+					case []byte:
+						scalar = (*C.byte)(&val[workItem*nbytes])
+					case [][]byte:
+						scalar = scalars[workItem]
+					case []Scalar:
+						if nbits > 248 {
+							scalar = &val[workItem].b[0]
+						} else {
+							scalar = scalars[workItem]
+						}
+					case []*Scalar:
+						scalar = scalars[workItem]
+					}
+
+					C.go_p1_mult_n_acc(&acc, &point.x, true,
+						scalar, C.size_t(nbits))
+				}
+
+				msgs <- acc
+			}()
+		}
+
+		ret := <-msgs
+		for tid := 1; tid < numThreads; tid++ {
+			point := <-msgs
+			C.blst_p1_add_or_double(&ret, &ret, &point)
+		}
+
+		for i := range scalars {
+			scalars[i] = nil
+		}
+
+		return &ret
+	}
+
 	// this is sizeof(scratch[0])
 	sz := int(C.blst_p1s_mult_pippenger_scratch_sizeof(0)) / 8
 
@@ -2852,7 +2917,7 @@ func P2AffinesMult(pointsIf interface{}, scalarsIf interface{}, nbits int) *P2 {
 
 	numThreads := numThreads(0)
 
-	if numThreads < 2 || npoints < 32 {
+	if numThreads < 2 {
 		sz := int(C.blst_p2s_mult_pippenger_scratch_sizeof(C.size_t(npoints))) / 8
 		scratch := make([]uint64, sz)
 
@@ -2901,6 +2966,71 @@ func P2AffinesMult(pointsIf interface{}, scalarsIf interface{}, nbits int) *P2 {
 		return &ret
 	}
 
+	if npoints < 32 {
+		if numThreads > npoints {
+			numThreads = npoints
+		}
+
+		curItem := uint32(0)
+		msgs := make(chan P2, numThreads)
+
+		for tid := 0; tid < numThreads; tid++ {
+			go func() {
+				var acc P2
+
+				for {
+					workItem := int(atomic.AddUint32(&curItem, 1) - 1)
+					if workItem >= npoints {
+						break
+					}
+
+					var point *P2Affine
+					switch val := pointsIf.(type) {
+					case []*P2Affine:
+						point = val[workItem]
+					case []P2Affine:
+						point = &val[workItem]
+					case P2Affines:
+						point = &val[workItem]
+					}
+
+					var scalar *C.byte
+					switch val := scalarsIf.(type) {
+					case []byte:
+						scalar = (*C.byte)(&val[workItem*nbytes])
+					case [][]byte:
+						scalar = scalars[workItem]
+					case []Scalar:
+						if nbits > 248 {
+							scalar = &val[workItem].b[0]
+						} else {
+							scalar = scalars[workItem]
+						}
+					case []*Scalar:
+						scalar = scalars[workItem]
+					}
+
+					C.go_p2_mult_n_acc(&acc, &point.x, true,
+						scalar, C.size_t(nbits))
+				}
+
+				msgs <- acc
+			}()
+		}
+
+		ret := <-msgs
+		for tid := 1; tid < numThreads; tid++ {
+			point := <-msgs
+			C.blst_p2_add_or_double(&ret, &ret, &point)
+		}
+
+		for i := range scalars {
+			scalars[i] = nil
+		}
+
+		return &ret
+	}
+
 	// this is sizeof(scratch[0])
 	sz := int(C.blst_p2s_mult_pippenger_scratch_sizeof(0)) / 8
 

diff --git a/bindings/go/blst_minpk_test.go b/bindings/go/blst_minpk_test.go
@@ -649,6 +649,13 @@ func TestMultiScalarP1(t *testing.T) {
     for i := range points {
         points[i] = *generator.Mult(scalars[i*4:(i+1)*4])
         refs[i]   = *points[i].Mult(scalars[i*16:(i+1)*16], 128)
+        if i < 27 {
+            ref := P1s(refs[:i+1]).Add()
+            ret := P1s(points[:i+1]).Mult(scalars, 128)
+            if !ref.Equals(ret) {
+                t.Errorf("failed self-consistency multi-scalar test")
+            }
+        }
     }
     ref := P1s(refs).Add()
     ret := P1s(points).Mult(scalars, 128)

diff --git a/bindings/go/blst_minsig_test.go b/bindings/go/blst_minsig_test.go
@@ -653,6 +653,13 @@ func TestMultiScalarP2(t *testing.T) {
     for i := range points {
         points[i] = *generator.Mult(scalars[i*4:(i+1)*4])
         refs[i]   = *points[i].Mult(scalars[i*16:(i+1)*16], 128)
+        if i < 27 {
+            ref := P2s(refs[:i+1]).Add()
+            ret := P2s(points[:i+1]).Mult(scalars, 128)
+            if !ref.Equals(ret) {
+                t.Errorf("failed self-consistency multi-scalar test")
+            }
+        }
     }
     ref := P2s(refs).Add()
     ret := P2s(points).Mult(scalars, 128)

diff --git a/bindings/go/blst_px.tgo b/bindings/go/blst_px.tgo
@@ -459,7 +459,7 @@ func P1AffinesMult(pointsIf interface{}, scalarsIf interface{}, nbits int) *P1 {
 
     numThreads := numThreads(0)
 
-    if numThreads < 2 || npoints < 32 {
+    if numThreads < 2 {
         sz := int(C.blst_p1s_mult_pippenger_scratch_sizeof(C.size_t(npoints)))/8
         scratch := make([]uint64, sz)
 
@@ -508,6 +508,71 @@ func P1AffinesMult(pointsIf interface{}, scalarsIf interface{}, nbits int) *P1 {
         return &ret
     }
 
+    if npoints < 32 {
+        if numThreads > npoints {
+            numThreads = npoints
+        }
+
+        curItem := uint32(0)
+        msgs := make(chan P1, numThreads)
+
+        for tid := 0; tid < numThreads; tid++ {
+            go func() {
+                var acc P1
+
+                for {
+                    workItem := int(atomic.AddUint32(&curItem, 1) - 1)
+                    if workItem >= npoints {
+                        break
+                    }
+
+                    var point *P1Affine
+                    switch val := pointsIf.(type) {
+                    case []*P1Affine:
+                        point = val[workItem]
+                    case []P1Affine:
+                        point = &val[workItem]
+                    case P1Affines:
+                        point = &val[workItem]
+                    }
+
+                    var scalar *C.byte
+                    switch val := scalarsIf.(type) {
+                    case []byte:
+                        scalar = (*C.byte)(&val[workItem*nbytes])
+                    case [][]byte:
+                        scalar = scalars[workItem]
+                    case []Scalar:
+                        if nbits > 248 {
+                            scalar = &val[workItem].b[0]
+                        } else {
+                            scalar = scalars[workItem]
+                        }
+                    case []*Scalar:
+                        scalar = scalars[workItem]
+                    }
+
+                    C.go_p1_mult_n_acc(&acc, &point.x, true,
+                                             scalar, C.size_t(nbits))
+                }
+
+                msgs <- acc
+            }()
+        }
+
+        ret := <-msgs
+        for tid := 1; tid < numThreads; tid++ {
+            point := <- msgs
+            C.blst_p1_add_or_double(&ret, &ret, &point);
+        }
+
+        for i := range(scalars) {
+            scalars[i] = nil
+        }
+
+        return &ret
+    }
+
     // this is sizeof(scratch[0])
     sz := int(C.blst_p1s_mult_pippenger_scratch_sizeof(0))/8