Extend SF patch #707257: Improve code generation
to cover the case for: "x,y,z=1,2,3". Gives a 30% speed-up.
Also, added FOR_ITER to the list of opcodes that can jump.
diff --git a/Python/compile.c b/Python/compile.c
index 3786cd9..57f0edb 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -364,23 +364,35 @@
break;
/* Replace BUILD_SEQN 2 UNPACK_SEQN 2 with ROT2 JMP+2.
+ Replace BUILD_SEQN 3 UNPACK_SEQN 3 with ROT3 ROT2 JMP+1.
Note, these opcodes occur together only in assignment
statements. Accordingly, the unpack opcode is never
a jump target. */
case BUILD_TUPLE:
case BUILD_LIST:
- if (codestr[i+3] != UNPACK_SEQUENCE ||
- GETARG(codestr, i) != 2 ||
- GETARG(codestr, i+3) != 2)
+ if (codestr[i+3] != UNPACK_SEQUENCE)
continue;
- codestr[i] = ROT_TWO;
- codestr[i+1] = JUMP_FORWARD;
- SETARG(codestr, i+1, 2);
- codestr[i+4] = DUP_TOP; /* Filler codes used as NOPs */
- codestr[i+5] = POP_TOP;
+ if (GETARG(codestr, i) == 2 && \
+ GETARG(codestr, i+3) == 2) {
+ codestr[i] = ROT_TWO;
+ codestr[i+1] = JUMP_FORWARD;
+ SETARG(codestr, i+1, 2);
+ codestr[i+4] = DUP_TOP; /* Filler codes used as NOPs */
+ codestr[i+5] = POP_TOP;
+ continue;
+ }
+ if (GETARG(codestr, i) == 3 && \
+ GETARG(codestr, i+3) == 3) {
+ codestr[i] = ROT_THREE;
+ codestr[i+1] = ROT_TWO;
+ codestr[i+2] = JUMP_FORWARD;
+ SETARG(codestr, i+2, 1);
+ codestr[i+5] = DUP_TOP;
+ }
break;
/* Replace jumps to unconditional jumps */
+ case FOR_ITER:
case JUMP_FORWARD:
case JUMP_IF_FALSE:
case JUMP_IF_TRUE: