prog: don't pad data in exec encoding

With leb128 ints it does not make any sense.
Reduces exec sizes a bit more:

- exec sizes: 10%:597 50%:1438 90%:7145
+ exec sizes: 10%:584 50%:1423 90%:7076

4 files changed, 8 insertions, 16 deletions

diff --git a/executor/executor.cc b/executor/executor.cc
index 84a8e0d43..ba2fb4bff 100644
--- a/executor/executor.cc
+++ b/executor/executor.cc
@@ -782,11 +782,10 @@ void execute_one()
 			case arg_data: {
 				uint64 size = read_input(&input_pos);
 				size &= ~(1ull << 63); // readable flag
-				uint64 padded = (size + 7) & ~7;
-				if (input_pos + padded > input_data + kMaxInput)
+				if (input_pos + size > input_data + kMaxInput)
 					fail("data arg overflow");
 				NONFAILING(memcpy(addr, input_pos, size));
-				input_pos += padded;
+				input_pos += size;
 				break;
 			}
 			case arg_csum: {
diff --git a/prog/decodeexec.go b/prog/decodeexec.go
index 4574ef845..bd92854e6 100644
--- a/prog/decodeexec.go
+++ b/prog/decodeexec.go
@@ -232,15 +232,14 @@ func (dec *execDecoder) read() uint64 {
 }
 
 func (dec *execDecoder) readBlob(size uint64) []byte {
-	padded := (size + 7) / 8 * 8
-	if uint64(len(dec.data)) < padded {
+	if uint64(len(dec.data)) < size {
 		dec.setErr(fmt.Errorf("exec program overflow"))
 	}
 	if dec.err != nil {
 		return nil
 	}
 	data := dec.data[:size]
-	dec.data = dec.data[padded:]
+	dec.data = dec.data[size:]
 	return data
 }
 
diff --git a/prog/encodingexec.go b/prog/encodingexec.go
index 2c13d452c..8e12d3491 100644
--- a/prog/encodingexec.go
+++ b/prog/encodingexec.go
@@ -283,7 +283,7 @@ func (w *execContext) writeArg(arg Arg) {
 	case *DataArg:
 		data := a.Data()
 		if len(data) == 0 {
-			return
+			panic("writing data arg with 0 size")
 		}
 		w.write(execArgData)
 		flags := uint64(len(data))
@@ -291,16 +291,11 @@ func (w *execContext) writeArg(arg Arg) {
 			flags |= execArgDataReadable
 		}
 		w.write(flags)
-		padded := len(data)
-		if pad := 8 - len(data)%8; pad != 8 {
-			padded += pad
-		}
-		if len(w.buf) < padded {
+		if len(w.buf) < len(data) {
 			w.eof = true
 		} else {
-			copy(w.buf, data)
-			copy(w.buf[len(data):], make([]byte, 8))
-			w.buf = w.buf[padded:]
+			n := copy(w.buf, data)
+			w.buf = w.buf[n:]
 		}
 	case *UnionArg:
 		w.writeArg(a.Option)
diff --git a/prog/encodingexec_test.go b/prog/encodingexec_test.go
index 2a8ce30b3..19b7d1761 100644
--- a/prog/encodingexec_test.go
+++ b/prog/encodingexec_test.go
@@ -522,7 +522,6 @@ test() (async, rerun: 10)
 					want = binary.AppendVarint(want, int64(elem))
 				case []byte:
 					want = append(want, elem...)
-					want = append(want, make([]byte, ((len(elem)+7) & ^7)-len(elem))...)
 				default:
 					t.Fatalf("unexpected elem type %T %#v", e, e)
 				}