diff options
Diffstat (limited to 'src/compiler/nir/nir_deref.c')
-rw-r--r-- | src/compiler/nir/nir_deref.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_deref.c b/src/compiler/nir/nir_deref.c index 762b21833cf..4e48f2b2da8 100644 --- a/src/compiler/nir/nir_deref.c +++ b/src/compiler/nir/nir_deref.c @@ -23,6 +23,63 @@ #include "nir.h" #include "nir_builder.h" +#include "nir_deref.h" + +void +nir_deref_path_init(nir_deref_path *path, + nir_deref_instr *deref, void *mem_ctx) +{ + assert(deref != NULL); + + /* The length of the short path is at most ARRAY_SIZE - 1 because we need + * room for the NULL terminator. + */ + static const int max_short_path_len = ARRAY_SIZE(path->_short_path) - 1; + + int count = 0; + + nir_deref_instr **tail = &path->_short_path[max_short_path_len]; + nir_deref_instr **head = tail; + + *tail = NULL; + for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) { + count++; + if (count <= max_short_path_len) + *(--head) = d; + } + + if (count <= max_short_path_len) { + /* If we're under max_short_path_len, just use the short path. */ + path->path = head; + goto done; + } + +#ifndef NDEBUG + /* Just in case someone uses short_path by accident */ + for (unsigned i = 0; i < ARRAY_SIZE(path->_short_path); i++) + path->_short_path[i] = (void *)0xdeadbeef; +#endif + + path->path = ralloc_array(mem_ctx, nir_deref_instr *, count + 1); + head = tail = path->path + count; + *tail = NULL; + for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) + *(--head) = d; + +done: + assert(head == path->path); + assert(tail == head + count); + assert((*head)->deref_type == nir_deref_type_var); + assert(*tail == NULL); +} + +void +nir_deref_path_finish(nir_deref_path *path) +{ + if (path->path < &path->_short_path[0] || + path->path > &path->_short_path[ARRAY_SIZE(path->_short_path) - 1]) + ralloc_free(path->path); +} /** * Recursively removes unused deref instructions |