diff --git a/src/simd/_gen/simdgen/ops/Moves/categories.yaml b/src/simd/_gen/simdgen/ops/Moves/categories.yaml
index 0c733e12ee1..49006f8801f 100644
--- a/src/simd/_gen/simdgen/ops/Moves/categories.yaml
+++ b/src/simd/_gen/simdgen/ops/Moves/categories.yaml
@@ -129,7 +129,7 @@
     // halves of the output.  The selection is chosen by the constant parameter h1h0l1l0
     // where each {h,l}{1,0} is two bits specify which element from y or x to select.
     // For example, {0,1,2,3}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7}) returns
-    // {2, 1, 4, 6} (don't forget that the binary constant is written big-endian).
+    // {2, 0, 5, 7} (don't forget that the binary constant is written big-endian).
 
 - go: concatSelectedConstant
   commutative: false
@@ -139,7 +139,7 @@
     // NAME concatenates selected elements from x and y into the lower and upper
     // halves of the output.  The selection is chosen by the constant parameter hilo
     // where hi and lo are each one bit specifying which 64-bit element to select
-    // from y and x.  For example {4,5}.concatSelectedConstant(0b10, {6,7})
+    // from y and x.  For example {4,5}.NAME(0b10, {6,7})
     // returns {4,7}; bit 0, selecting from x, is zero, and selects 4, and bit 1,
     // selecting from y, is 1, and selects 7.
 
@@ -147,13 +147,14 @@
   commutative: false
   out:
     - elemBits: 32
+      bits: 256
   documentation: !string |-
     // NAME concatenates selected elements from 128-bit subvectors of x and y
     // into the lower and upper halves of corresponding subvectors of the output.
     // The selection is chosen by the constant parameter h1h0l1l0
-    // where each {h,l}{1,0} is two bits specify which element from y or x to select.
+    // where each {h,l}{1,0} is two bits specifying which element from y or x to select.
     // For example,
-    // {0,1,2,3,8,9,10,11}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
+    // {0,1,2,3,8,9,10,11}.NAME(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
     // returns {2,0,5,7,10,8,13,15}
     // (don't forget that the binary constant is written big-endian).
 
@@ -161,6 +162,7 @@
   commutative: false
   out:
     - elemBits: 64
+      bits: 256
   documentation: !string |-
     // NAME concatenates selected elements from 128-bit subvectors of x and y
     // into the lower and upper halves of corresponding subvectors of the output.
@@ -168,7 +170,7 @@
     // hi and lo pair select 64-bit elements from the corresponding 128-bit
     // subvectors of x and y.
     //
-    // For example {4,5,8,9}.concatSelectedConstant(0b_11_10, {6,7,10,11})
+    // For example {4,5,8,9}.NAME(0b_11_10, {6,7,10,11})
     // returns {4,7,9,11}; bit 0 is zero, selecting element 0 from x's least
     // 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
     // then 1, selecting element 1 from x's upper 128 bits (9), then 1,
@@ -176,6 +178,44 @@
     // This differs from the same method applied to a 32x8 vector, where
     // the 8-bit constant performs the same selection on both subvectors.
 
+- go: concatSelectedConstantGrouped
+  commutative: false
+  out:
+    - elemBits: 32
+      bits: 512
+  documentation: !string |-
+    // NAME concatenates selected elements from 128-bit subvectors of x and y
+    // into the lower and upper halves of corresponding subvectors of the output.
+    // The selection is chosen by the constant parameter h1h0l1l0
+    // where each {h,l}{1,0} is two bits specifying which element from y or x to select.
+    // For example,
+    // {0,1,2,3,8,9,10,11, 20,21,22,23,28,29,210,211}.NAME(
+    //             0b_11_01_00_10, {4,5,6,7,12,13,14,15, 24,25,26,27,212,213,214,215})
+    // returns {2,0,5,7,10,8,13,15, 22,20,25,27,210,28,213,215}
+    // (don't forget that the binary constant is written big-endian).
+
+- go: concatSelectedConstantGrouped
+  commutative: false
+  out:
+    - elemBits: 64
+      bits: 512
+  documentation: !string |-
+    // NAME concatenates selected elements from 128-bit subvectors of x and y
+    // into the lower and upper halves of corresponding subvectors of the output.
+    // The selections are specified by the constant parameter hilos where each
+    // hi and lo pair select 64-bit elements from the corresponding 128-bit
+    // subvectors of x and y.
+    //
+    // For example {4,5,8,9,12,13,16,17}.NAME(0b11_00_11_10, {6,7,10,11,14,15,18,19})
+    // returns {4,7,9,11,12,14,17,19}; bit 0 is zero, selecting element 0 from x's 
+    // least 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
+    // then 1, selecting element 1 from x's next 128 bits (9), then 1,
+    // selecting element 1 from y's upper 128 bits (11).  The next two 0 bits select
+    // the lower elements from x and y's 3rd 128 bit groups (12, 14), the last two
+    // 1 bits select the upper elements from x and y's last 128 bits (17, 19).
+    // This differs from the same method applied to a 32x8 or 32x16 vector, where
+    // the 8-bit constant performs the same selection on all the subvectors.
+
 - go: Select128FromPair
   commutative: false
   documentation: !string |-
diff --git a/src/simd/ops_amd64.go b/src/simd/ops_amd64.go
index 91e7d91842a..17f45e6bf5e 100644
--- a/src/simd/ops_amd64.go
+++ b/src/simd/ops_amd64.go
@@ -7431,7 +7431,7 @@ func (x Int64x8) blendMasked(y Int64x8, mask Mask64x8) Int64x8
 // halves of the output.  The selection is chosen by the constant parameter h1h0l1l0
 // where each {h,l}{1,0} is two bits specify which element from y or x to select.
 // For example, {0,1,2,3}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7}) returns
-// {2, 1, 4, 6} (don't forget that the binary constant is written big-endian).
+// {2, 0, 5, 7} (don't forget that the binary constant is written big-endian).
 //
 // h1h0l1l0 results in better performance when it's a constant, a non-constant value will be translated into a jump table.
 //
@@ -7454,7 +7454,7 @@ func (x Float64x2) concatSelectedConstant(hilo uint8, y Float64x2) Float64x2
 // halves of the output.  The selection is chosen by the constant parameter h1h0l1l0
 // where each {h,l}{1,0} is two bits specify which element from y or x to select.
 // For example, {0,1,2,3}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7}) returns
-// {2, 1, 4, 6} (don't forget that the binary constant is written big-endian).
+// {2, 0, 5, 7} (don't forget that the binary constant is written big-endian).
 //
 // h1h0l1l0 results in better performance when it's a constant, a non-constant value will be translated into a jump table.
 //
@@ -7477,7 +7477,7 @@ func (x Int64x2) concatSelectedConstant(hilo uint8, y Int64x2) Int64x2
 // halves of the output.  The selection is chosen by the constant parameter h1h0l1l0
 // where each {h,l}{1,0} is two bits specify which element from y or x to select.
 // For example, {0,1,2,3}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7}) returns
-// {2, 1, 4, 6} (don't forget that the binary constant is written big-endian).
+// {2, 0, 5, 7} (don't forget that the binary constant is written big-endian).
 //
 // h1h0l1l0 results in better performance when it's a constant, a non-constant value will be translated into a jump table.
 //
@@ -7501,9 +7501,9 @@ func (x Uint64x2) concatSelectedConstant(hilo uint8, y Uint64x2) Uint64x2
 // concatSelectedConstantGrouped concatenates selected elements from 128-bit subvectors of x and y
 // into the lower and upper halves of corresponding subvectors of the output.
 // The selection is chosen by the constant parameter h1h0l1l0
-// where each {h,l}{1,0} is two bits specify which element from y or x to select.
+// where each {h,l}{1,0} is two bits specifying which element from y or x to select.
 // For example,
-// {0,1,2,3,8,9,10,11}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
+// {0,1,2,3,8,9,10,11}.concatSelectedConstantGrouped(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
 // returns {2,0,5,7,10,8,13,15}
 // (don't forget that the binary constant is written big-endian).
 //
@@ -7515,10 +7515,13 @@ func (x Float32x8) concatSelectedConstantGrouped(h1h0l1l0 uint8, y Float32x8) Fl
 // concatSelectedConstantGrouped concatenates selected elements from 128-bit subvectors of x and y
 // into the lower and upper halves of corresponding subvectors of the output.
 // The selection is chosen by the constant parameter h1h0l1l0
-// where each {h,l}{1,0} is two bits specify which element from y or x to select.
+// where each {h,l}{1,0} is two bits specifying which element from y or x to select.
 // For example,
-// {0,1,2,3,8,9,10,11}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
-// returns {2,0,5,7,10,8,13,15}
+// {0,1,2,3,8,9,10,11, 20,21,22,23,28,29,210,211}.concatSelectedConstantGrouped(
+//
+//	0b_11_01_00_10, {4,5,6,7,12,13,14,15, 24,25,26,27,212,213,214,215})
+//
+// returns {2,0,5,7,10,8,13,15, 22,20,25,27,210,28,213,215}
 // (don't forget that the binary constant is written big-endian).
 //
 // h1h0l1l0 results in better performance when it's a constant, a non-constant value will be translated into a jump table.
@@ -7532,7 +7535,7 @@ func (x Float32x16) concatSelectedConstantGrouped(h1h0l1l0 uint8, y Float32x16)
 // hi and lo pair select 64-bit elements from the corresponding 128-bit
 // subvectors of x and y.
 //
-// For example {4,5,8,9}.concatSelectedConstant(0b_11_10, {6,7,10,11})
+// For example {4,5,8,9}.concatSelectedConstantGrouped(0b_11_10, {6,7,10,11})
 // returns {4,7,9,11}; bit 0 is zero, selecting element 0 from x's least
 // 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
 // then 1, selecting element 1 from x's upper 128 bits (9), then 1,
@@ -7551,13 +7554,15 @@ func (x Float64x4) concatSelectedConstantGrouped(hilos uint8, y Float64x4) Float
 // hi and lo pair select 64-bit elements from the corresponding 128-bit
 // subvectors of x and y.
 //
-// For example {4,5,8,9}.concatSelectedConstant(0b_11_10, {6,7,10,11})
-// returns {4,7,9,11}; bit 0 is zero, selecting element 0 from x's least
-// 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
-// then 1, selecting element 1 from x's upper 128 bits (9), then 1,
-// selecting element 1 from y's upper 128 bits (11).
-// This differs from the same method applied to a 32x8 vector, where
-// the 8-bit constant performs the same selection on both subvectors.
+// For example {4,5,8,9,12,13,16,17}.concatSelectedConstantGrouped(0b11_00_11_10, {6,7,10,11,14,15,18,19})
+// returns {4,7,9,11,12,14,17,19}; bit 0 is zero, selecting element 0 from x's
+// least 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
+// then 1, selecting element 1 from x's next 128 bits (9), then 1,
+// selecting element 1 from y's upper 128 bits (11).  The next two 0 bits select
+// the lower elements from x and y's 3rd 128 bit groups (12, 14), the last two
+// 1 bits select the upper elements from x and y's last 128 bits (17, 19).
+// This differs from the same method applied to a 32x8 or 32x16 vector, where
+// the 8-bit constant performs the same selection on all the subvectors.
 //
 // hilos results in better performance when it's a constant, a non-constant value will be translated into a jump table.
 //
@@ -7567,9 +7572,9 @@ func (x Float64x8) concatSelectedConstantGrouped(hilos uint8, y Float64x8) Float
 // concatSelectedConstantGrouped concatenates selected elements from 128-bit subvectors of x and y
 // into the lower and upper halves of corresponding subvectors of the output.
 // The selection is chosen by the constant parameter h1h0l1l0
-// where each {h,l}{1,0} is two bits specify which element from y or x to select.
+// where each {h,l}{1,0} is two bits specifying which element from y or x to select.
 // For example,
-// {0,1,2,3,8,9,10,11}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
+// {0,1,2,3,8,9,10,11}.concatSelectedConstantGrouped(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
 // returns {2,0,5,7,10,8,13,15}
 // (don't forget that the binary constant is written big-endian).
 //
@@ -7581,10 +7586,13 @@ func (x Int32x8) concatSelectedConstantGrouped(h1h0l1l0 uint8, y Int32x8) Int32x
 // concatSelectedConstantGrouped concatenates selected elements from 128-bit subvectors of x and y
 // into the lower and upper halves of corresponding subvectors of the output.
 // The selection is chosen by the constant parameter h1h0l1l0
-// where each {h,l}{1,0} is two bits specify which element from y or x to select.
+// where each {h,l}{1,0} is two bits specifying which element from y or x to select.
 // For example,
-// {0,1,2,3,8,9,10,11}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
-// returns {2,0,5,7,10,8,13,15}
+// {0,1,2,3,8,9,10,11, 20,21,22,23,28,29,210,211}.concatSelectedConstantGrouped(
+//
+//	0b_11_01_00_10, {4,5,6,7,12,13,14,15, 24,25,26,27,212,213,214,215})
+//
+// returns {2,0,5,7,10,8,13,15, 22,20,25,27,210,28,213,215}
 // (don't forget that the binary constant is written big-endian).
 //
 // h1h0l1l0 results in better performance when it's a constant, a non-constant value will be translated into a jump table.
@@ -7598,7 +7606,7 @@ func (x Int32x16) concatSelectedConstantGrouped(h1h0l1l0 uint8, y Int32x16) Int3
 // hi and lo pair select 64-bit elements from the corresponding 128-bit
 // subvectors of x and y.
 //
-// For example {4,5,8,9}.concatSelectedConstant(0b_11_10, {6,7,10,11})
+// For example {4,5,8,9}.concatSelectedConstantGrouped(0b_11_10, {6,7,10,11})
 // returns {4,7,9,11}; bit 0 is zero, selecting element 0 from x's least
 // 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
 // then 1, selecting element 1 from x's upper 128 bits (9), then 1,
@@ -7617,13 +7625,15 @@ func (x Int64x4) concatSelectedConstantGrouped(hilos uint8, y Int64x4) Int64x4
 // hi and lo pair select 64-bit elements from the corresponding 128-bit
 // subvectors of x and y.
 //
-// For example {4,5,8,9}.concatSelectedConstant(0b_11_10, {6,7,10,11})
-// returns {4,7,9,11}; bit 0 is zero, selecting element 0 from x's least
-// 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
-// then 1, selecting element 1 from x's upper 128 bits (9), then 1,
-// selecting element 1 from y's upper 128 bits (11).
-// This differs from the same method applied to a 32x8 vector, where
-// the 8-bit constant performs the same selection on both subvectors.
+// For example {4,5,8,9,12,13,16,17}.concatSelectedConstantGrouped(0b11_00_11_10, {6,7,10,11,14,15,18,19})
+// returns {4,7,9,11,12,14,17,19}; bit 0 is zero, selecting element 0 from x's
+// least 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
+// then 1, selecting element 1 from x's next 128 bits (9), then 1,
+// selecting element 1 from y's upper 128 bits (11).  The next two 0 bits select
+// the lower elements from x and y's 3rd 128 bit groups (12, 14), the last two
+// 1 bits select the upper elements from x and y's last 128 bits (17, 19).
+// This differs from the same method applied to a 32x8 or 32x16 vector, where
+// the 8-bit constant performs the same selection on all the subvectors.
 //
 // hilos results in better performance when it's a constant, a non-constant value will be translated into a jump table.
 //
@@ -7633,9 +7643,9 @@ func (x Int64x8) concatSelectedConstantGrouped(hilos uint8, y Int64x8) Int64x8
 // concatSelectedConstantGrouped concatenates selected elements from 128-bit subvectors of x and y
 // into the lower and upper halves of corresponding subvectors of the output.
 // The selection is chosen by the constant parameter h1h0l1l0
-// where each {h,l}{1,0} is two bits specify which element from y or x to select.
+// where each {h,l}{1,0} is two bits specifying which element from y or x to select.
 // For example,
-// {0,1,2,3,8,9,10,11}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
+// {0,1,2,3,8,9,10,11}.concatSelectedConstantGrouped(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
 // returns {2,0,5,7,10,8,13,15}
 // (don't forget that the binary constant is written big-endian).
 //
@@ -7647,10 +7657,13 @@ func (x Uint32x8) concatSelectedConstantGrouped(h1h0l1l0 uint8, y Uint32x8) Uint
 // concatSelectedConstantGrouped concatenates selected elements from 128-bit subvectors of x and y
 // into the lower and upper halves of corresponding subvectors of the output.
 // The selection is chosen by the constant parameter h1h0l1l0
-// where each {h,l}{1,0} is two bits specify which element from y or x to select.
+// where each {h,l}{1,0} is two bits specifying which element from y or x to select.
 // For example,
-// {0,1,2,3,8,9,10,11}.concatSelectedConstant(0b_11_01_00_10, {4,5,6,7,12,13,14,15})
-// returns {2,0,5,7,10,8,13,15}
+// {0,1,2,3,8,9,10,11, 20,21,22,23,28,29,210,211}.concatSelectedConstantGrouped(
+//
+//	0b_11_01_00_10, {4,5,6,7,12,13,14,15, 24,25,26,27,212,213,214,215})
+//
+// returns {2,0,5,7,10,8,13,15, 22,20,25,27,210,28,213,215}
 // (don't forget that the binary constant is written big-endian).
 //
 // h1h0l1l0 results in better performance when it's a constant, a non-constant value will be translated into a jump table.
@@ -7664,7 +7677,7 @@ func (x Uint32x16) concatSelectedConstantGrouped(h1h0l1l0 uint8, y Uint32x16) Ui
 // hi and lo pair select 64-bit elements from the corresponding 128-bit
 // subvectors of x and y.
 //
-// For example {4,5,8,9}.concatSelectedConstant(0b_11_10, {6,7,10,11})
+// For example {4,5,8,9}.concatSelectedConstantGrouped(0b_11_10, {6,7,10,11})
 // returns {4,7,9,11}; bit 0 is zero, selecting element 0 from x's least
 // 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
 // then 1, selecting element 1 from x's upper 128 bits (9), then 1,
@@ -7683,13 +7696,15 @@ func (x Uint64x4) concatSelectedConstantGrouped(hilos uint8, y Uint64x4) Uint64x
 // hi and lo pair select 64-bit elements from the corresponding 128-bit
 // subvectors of x and y.
 //
-// For example {4,5,8,9}.concatSelectedConstant(0b_11_10, {6,7,10,11})
-// returns {4,7,9,11}; bit 0 is zero, selecting element 0 from x's least
-// 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
-// then 1, selecting element 1 from x's upper 128 bits (9), then 1,
-// selecting element 1 from y's upper 128 bits (11).
-// This differs from the same method applied to a 32x8 vector, where
-// the 8-bit constant performs the same selection on both subvectors.
+// For example {4,5,8,9,12,13,16,17}.concatSelectedConstantGrouped(0b11_00_11_10, {6,7,10,11,14,15,18,19})
+// returns {4,7,9,11,12,14,17,19}; bit 0 is zero, selecting element 0 from x's
+// least 128-bits (4), then 1, selects the element 1 from y's least 128-bits (7),
+// then 1, selecting element 1 from x's next 128 bits (9), then 1,
+// selecting element 1 from y's upper 128 bits (11).  The next two 0 bits select
+// the lower elements from x and y's 3rd 128 bit groups (12, 14), the last two
+// 1 bits select the upper elements from x and y's last 128 bits (17, 19).
+// This differs from the same method applied to a 32x8 or 32x16 vector, where
+// the 8-bit constant performs the same selection on all the subvectors.
 //
 // hilos results in better performance when it's a constant, a non-constant value will be translated into a jump table.
 //