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| author | Neil Schemenauer <nascheme@enme.ucalgary.ca> | 2009-10-14 19:14:38 (GMT) |
|---|---|---|
| committer | Neil Schemenauer <nascheme@enme.ucalgary.ca> | 2009-10-14 19:14:38 (GMT) |
| commit | e441cb71c73649da991d8bc418650f2748a58f72 (patch) | |
| tree | b66219e97e32365d78713941065d74315d8d026d /Python/compile.c | |
| parent | 46afef330f88ddcf4106094e86f54f90dbdec390 (diff) | |
| download | cpython-e441cb71c73649da991d8bc418650f2748a58f72.zip cpython-e441cb71c73649da991d8bc418650f2748a58f72.tar.gz cpython-e441cb71c73649da991d8bc418650f2748a58f72.tar.bz2 | |
Issue #1754094: Improve the stack depth calculation in the compiler.
There should be no other effect than a small decrease in memory use.
Diffstat (limited to 'Python/compile.c')
| -rw-r--r-- | Python/compile.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/Python/compile.c b/Python/compile.c index 24975b6..d06a03b 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -772,7 +772,7 @@ opcode_stack_effect(int opcode, int oparg) case UNPACK_EX: return (oparg&0xFF) + (oparg>>8); case FOR_ITER: - return 1; + return 1; /* or -1, at end of iterator */ case STORE_ATTR: return -2; @@ -799,7 +799,7 @@ opcode_stack_effect(int opcode, int oparg) case COMPARE_OP: return -1; case IMPORT_NAME: - return 0; + return -1; case IMPORT_FROM: return 1; @@ -3546,7 +3546,7 @@ dfs(struct compiler *c, basicblock *b, struct assembler *a) static int stackdepth_walk(struct compiler *c, basicblock *b, int depth, int maxdepth) { - int i; + int i, target_depth; struct instr *instr; if (b->b_seen || b->b_startdepth >= depth) return maxdepth; @@ -3559,8 +3559,17 @@ stackdepth_walk(struct compiler *c, basicblock *b, int depth, int maxdepth) maxdepth = depth; assert(depth >= 0); /* invalid code or bug in stackdepth() */ if (instr->i_jrel || instr->i_jabs) { + target_depth = depth; + if (instr->i_opcode == FOR_ITER) { + target_depth = depth-2; + } else if (instr->i_opcode == SETUP_FINALLY || + instr->i_opcode == SETUP_EXCEPT) { + target_depth = depth+3; + if (target_depth > maxdepth) + maxdepth = target_depth; + } maxdepth = stackdepth_walk(c, instr->i_target, - depth, maxdepth); + target_depth, maxdepth); if (instr->i_opcode == JUMP_ABSOLUTE || instr->i_opcode == JUMP_FORWARD) { goto out; /* remaining code is dead */ |