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| author | Georg-Johann Lay <avr@gjlay.de> | 2024-08-30 19:38:30 +0200 |
|---|---|---|
| committer | Georg-Johann Lay <avr@gjlay.de> | 2024-08-31 20:30:40 +0200 |
| commit | df89afbb7732bdf9f003af0020a46b6deb3c4eeb (patch) | |
| tree | d4c3a4a9aa1ad79e3cbf167542220208130aa7f9 /gcc | |
| parent | 60fc5501ddc77d496f1584532c29d209eea13734 (diff) | |
| download | gcc-df89afbb7732bdf9f003af0020a46b6deb3c4eeb.zip gcc-df89afbb7732bdf9f003af0020a46b6deb3c4eeb.tar.gz gcc-df89afbb7732bdf9f003af0020a46b6deb3c4eeb.tar.bz2 | |
AVR: Run pass avr-fuse-add a second time after pass_cprop_hardreg.
gcc/
* config/avr/avr-passes.cc (avr_pass_fuse_add) <clone>: Override.
* config/avr/avr-passes.def (avr_pass_fuse_add): Run again
after pass_cprop_hardreg.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/avr/avr-passes.cc | 7 | ||||
| -rw-r--r-- | gcc/config/avr/avr-passes.def | 21 |
2 files changed, 28 insertions, 0 deletions
diff --git a/gcc/config/avr/avr-passes.cc b/gcc/config/avr/avr-passes.cc index 58b132b..8a71b57 100644 --- a/gcc/config/avr/avr-passes.cc +++ b/gcc/config/avr/avr-passes.cc @@ -1026,6 +1026,13 @@ public: this->name = name; } + // Cloning is required because we are running one instance of the pass + // before peephole2. and a second one after cprop_hardreg. + opt_pass * clone () final override + { + return make_avr_pass_fuse_add (m_ctxt); + } + bool gate (function *) final override { return optimize && avr_fuse_add > 0; diff --git a/gcc/config/avr/avr-passes.def b/gcc/config/avr/avr-passes.def index 3be82e0..cd89d67 100644 --- a/gcc/config/avr/avr-passes.def +++ b/gcc/config/avr/avr-passes.def @@ -26,6 +26,27 @@ INSERT_PASS_BEFORE (pass_peephole2, 1, avr_pass_fuse_add); +/* There are cases where avr-fuse-add doesn't find POST_INC cases because + the RTL code at that time is too long-winded, and moves registers back and + forth (which seems to be the same reason for why pass auto_inc_dec cannot + find POST_INC, either). Some of that long-windedness is cleaned up very + late in pass cprop_hardreg, which opens up new opportunities to find post + increments. An example is the following function from AVR-LibC's qsort: + + void swapfunc (char *a, char *b, int n) + { + do + { + char tmp = *a; + *a++ = *b; + *b++ = tmp; + } while (--n > 0); + } + + Hence, run avr-fuse-add twice; the second time after cprop_hardreg. */ + +INSERT_PASS_AFTER (pass_cprop_hardreg, 1, avr_pass_fuse_add); + /* An analysis pass that runs prior to prologue / epilogue generation. Computes cfun->machine->gasisr.maybe which is used in prologue and epilogue generation provided -mgas-isr-prologues is on. */ |