diff options
Diffstat (limited to 'gcc/print-rtl.h')
| -rw-r--r-- | gcc/print-rtl.h | 81 |
1 files changed, 80 insertions, 1 deletions
diff --git a/gcc/print-rtl.h b/gcc/print-rtl.h index e722038..5f7cefb 100644 --- a/gcc/print-rtl.h +++ b/gcc/print-rtl.h @@ -20,12 +20,19 @@ along with GCC; see the file COPYING3. If not see #ifndef GCC_PRINT_RTL_H #define GCC_PRINT_RTL_H +#ifndef GENERATOR_FILE +#include "bitmap.h" +#endif /* #ifndef GENERATOR_FILE */ + +class rtx_reuse_manager; + /* A class for writing rtx to a FILE *. */ class rtx_writer { public: - rtx_writer (FILE *outfile, int ind, bool simple, bool compact); + rtx_writer (FILE *outfile, int ind, bool simple, bool compact, + rtx_reuse_manager *reuse_manager); void print_rtx (const_rtx in_rtx); void print_rtl (const_rtx rtx_first); @@ -60,6 +67,9 @@ class rtx_writer printed with a '%' sigil e.g. "%0" for (LAST_VIRTUAL_REGISTER + 1), - insn names are prefixed with "c" (e.g. "cinsn", "cnote", etc). */ bool m_compact; + + /* An optional instance of rtx_reuse_manager. */ + rtx_reuse_manager *m_rtx_reuse_manager; }; #ifdef BUFSIZ @@ -80,4 +90,73 @@ extern const char *str_pattern_slim (const_rtx); extern void print_rtx_function (FILE *file, function *fn, bool compact); +#ifndef GENERATOR_FILE + +/* For some rtx codes (such as SCRATCH), instances are defined to only be + equal for pointer equality: two distinct SCRATCH instances are non-equal. + copy_rtx preserves this equality by reusing the SCRATCH instance. + + For example, in this x86 instruction: + + (cinsn (set (mem/v:BLK (scratch:DI) [0 A8]) + (unspec:BLK [ + (mem/v:BLK (scratch:DI) [0 A8]) + ] UNSPEC_MEMORY_BLOCKAGE)) "test.c":2 + (nil)) + + the two instances of "(scratch:DI)" are actually the same underlying + rtx pointer (and thus "equal"), and the insn will only be recognized + (as "*memory_blockage") if this pointer-equality is preserved. + + To be able to preserve this pointer-equality when round-tripping + through dumping/loading the rtl, we need some syntax. The first + time a reused rtx is encountered in the dump, we prefix it with + a reuse ID: + + (0|scratch:DI) + + Subsequent references to the rtx in the dump can be expressed using + "reuse_rtx" e.g.: + + (reuse_rtx 0) + + This class is responsible for tracking a set of reuse IDs during a dump. + + Dumping with reuse-support is done in two passes: + + (a) a first pass in which "preprocess" is called on each top-level rtx + to be seen in the dump. This traverses the rtx and its descendents, + identifying rtx that will be seen more than once in the actual dump, + and assigning them reuse IDs. + + (b) the actual dump, via print_rtx etc. print_rtx detect the presence + of a live rtx_reuse_manager and uses it if there is one. Any rtx + that were assigned reuse IDs will be printed with it the first time + that they are seen, and then printed as "(reuse_rtx ID)" subsequently. + + The first phase is needed since otherwise there would be no way to tell + if an rtx will be reused when first encountering it. */ + +class rtx_reuse_manager +{ + public: + rtx_reuse_manager (); + + /* The first pass. */ + void preprocess (const_rtx x); + + /* The second pass (within print_rtx). */ + bool has_reuse_id (const_rtx x, int *out); + bool seen_def_p (int reuse_id); + void set_seen_def (int reuse_id); + + private: + hash_map<const_rtx, int> m_rtx_occurrence_count; + hash_map<const_rtx, int> m_rtx_reuse_ids; + bitmap_head m_defs_seen; + int m_next_id; +}; + +#endif /* #ifndef GENERATOR_FILE */ + #endif // GCC_PRINT_RTL_H |