blas/gonum: avoid bounds checks in Ztbmv

gonum · Apr 25, 2018 · 0802470 · 0802470
1 parent 47734a4
commit 0802470
Showing 1 changed file with 32 additions and 16 deletions.
diff --git a/blas/gonum/level2cmplx128.go b/blas/gonum/level2cmplx128.go
@@ -1273,52 +1273,60 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 		if uplo == blas.Upper {
 			if incX == 1 {
 				for i := 0; i < n; i++ {
+					xi := x[i]
 					if diag == blas.NonUnit {
-						x[i] *= ab[i*ldab]
+						xi *= ab[i*ldab]
 					}
 					kk := min(k, n-i-1)
 					for j, aij := range ab[i*ldab+1 : i*ldab+kk+1] {
-						x[i] += x[i+j+1] * aij
+						xi += x[i+j+1] * aij
 					}
+					x[i] = xi
 				}
 			} else {
 				ix := kx
 				for i := 0; i < n; i++ {
+					xi := x[ix]
 					if diag == blas.NonUnit {
-						x[ix] *= ab[i*ldab]
+						xi *= ab[i*ldab]
 					}
 					kk := min(k, n-i-1)
 					jx := ix + incX
 					for _, aij := range ab[i*ldab+1 : i*ldab+kk+1] {
-						x[ix] += x[jx] * aij
+						xi += x[jx] * aij
 						jx += incX
 					}
+					x[ix] = xi
 					ix += incX
 				}
 			}
 		} else {
 			if incX == 1 {
 				for i := n - 1; i >= 0; i-- {
+					xi := x[i]
 					if diag == blas.NonUnit {
-						x[i] *= ab[i*ldab+k]
+						xi *= ab[i*ldab+k]
 					}
 					kk := min(k, i)
 					for j, aij := range ab[i*ldab+k-kk : i*ldab+k] {
-						x[i] += x[i-kk+j] * aij
+						xi += x[i-kk+j] * aij
 					}
+					x[i] = xi
 				}
 			} else {
 				ix := kx + (n-1)*incX
 				for i := n - 1; i >= 0; i-- {
+					xi := x[ix]
 					if diag == blas.NonUnit {
-						x[ix] *= ab[i*ldab+k]
+						xi *= ab[i*ldab+k]
 					}
 					kk := min(k, i)
 					jx := ix - kk*incX
 					for _, aij := range ab[i*ldab+k-kk : i*ldab+k] {
-						x[ix] += x[jx] * aij
+						xi += x[jx] * aij
 						jx += incX
 					}
+					x[ix] = xi
 					ix -= incX
 				}
 			}
@@ -1328,8 +1336,9 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 			if incX == 1 {
 				for i := n - 1; i >= 0; i-- {
 					kk := min(k, n-i-1)
+					xi := x[i]
 					for j, aij := range ab[i*ldab+1 : i*ldab+kk+1] {
-						x[i+j+1] += x[i] * aij
+						x[i+j+1] += xi * aij
 					}
 					if diag == blas.NonUnit {
 						x[i] *= ab[i*ldab]
@@ -1340,8 +1349,9 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 				for i := n - 1; i >= 0; i-- {
 					kk := min(k, n-i-1)
 					jx := ix + incX
+					xi := x[ix]
 					for _, aij := range ab[i*ldab+1 : i*ldab+kk+1] {
-						x[jx] += x[ix] * aij
+						x[jx] += xi * aij
 						jx += incX
 					}
 					if diag == blas.NonUnit {
@@ -1354,8 +1364,9 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 			if incX == 1 {
 				for i := 0; i < n; i++ {
 					kk := min(k, i)
+					xi := x[i]
 					for j, aij := range ab[i*ldab+k-kk : i*ldab+k] {
-						x[i-kk+j] += x[i] * aij
+						x[i-kk+j] += xi * aij
 					}
 					if diag == blas.NonUnit {
 						x[i] *= ab[i*ldab+k]
@@ -1366,8 +1377,9 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 				for i := 0; i < n; i++ {
 					kk := min(k, i)
 					jx := ix - kk*incX
+					xi := x[ix]
 					for _, aij := range ab[i*ldab+k-kk : i*ldab+k] {
-						x[jx] += x[ix] * aij
+						x[jx] += xi * aij
 						jx += incX
 					}
 					if diag == blas.NonUnit {
@@ -1382,8 +1394,9 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 			if incX == 1 {
 				for i := n - 1; i >= 0; i-- {
 					kk := min(k, n-i-1)
+					xi := x[i]
 					for j, aij := range ab[i*ldab+1 : i*ldab+kk+1] {
-						x[i+j+1] += x[i] * cmplx.Conj(aij)
+						x[i+j+1] += xi * cmplx.Conj(aij)
 					}
 					if diag == blas.NonUnit {
 						x[i] *= cmplx.Conj(ab[i*ldab])
@@ -1394,8 +1407,9 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 				for i := n - 1; i >= 0; i-- {
 					kk := min(k, n-i-1)
 					jx := ix + incX
+					xi := x[ix]
 					for _, aij := range ab[i*ldab+1 : i*ldab+kk+1] {
-						x[jx] += x[ix] * cmplx.Conj(aij)
+						x[jx] += xi * cmplx.Conj(aij)
 						jx += incX
 					}
 					if diag == blas.NonUnit {
@@ -1408,8 +1422,9 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 			if incX == 1 {
 				for i := 0; i < n; i++ {
 					kk := min(k, i)
+					xi := x[i]
 					for j, aij := range ab[i*ldab+k-kk : i*ldab+k] {
-						x[i-kk+j] += x[i] * cmplx.Conj(aij)
+						x[i-kk+j] += xi * cmplx.Conj(aij)
 					}
 					if diag == blas.NonUnit {
 						x[i] *= cmplx.Conj(ab[i*ldab+k])
@@ -1420,8 +1435,9 @@ func (Implementation) Ztbmv(uplo blas.Uplo, trans blas.Transpose, diag blas.Diag
 				for i := 0; i < n; i++ {
 					kk := min(k, i)
 					jx := ix - kk*incX
+					xi := x[ix]
 					for _, aij := range ab[i*ldab+k-kk : i*ldab+k] {
-						x[jx] += x[ix] * cmplx.Conj(aij)
+						x[jx] += xi * cmplx.Conj(aij)
 						jx += incX
 					}
 					if diag == blas.NonUnit {